Patent Publication Number: US-2021177608-A1

Title: Hip joint device and method

Description:
FIELD OF INVENTION 
     The present invention relates generally to a medical device for implantation in a hip joint, and a method of providing said medical device. 
     BACKGROUND 
     Hip joint Osteoarthritis is a syndrome in which low-grade inflammation results in pain in the hip joints, caused by abnormal wearing of the Cartilage that acts as a cushion inside if the hip joint. This abnormal wearing of the cartilage also results in a decrease of the joints lubricating fluid called Synovial fluid. Hip joint Osteoarthritis is estimated to affect 80% of all people over 65 years of age, in more or less serious forms. 
     The present treatment for hip osteoarthritis comprises NSAID drugs, local injections of Hyaluronic acid or Glucocorticoid to help lubricating the hip joint, and replacing parts of the hip joint with a prosthesis through hip joint surgery. 
     The replacing of parts of the hip joint is one of the most common surgeries to date performed at hundreds of thousand of patients in the world every year. The most common method comprises placing a metal prosthesis in Femur and a plastic bowl in Acetabulum. This operation is usually done through a lateral incision in the hip and upper thigh and through, Fascia Lata and the lateral muscles of the thigh. To get access to the hip joint, the supporting hip joint capsule attached to Femur and Ilium of Pelvis needs to be penetrated, making it difficult to get a fully functional joint after the surgery. Femur is then cut at the neck with a bone saw and the prosthesis is placed in femur either with bone cement or without. Acetabulum is slightly enlarged using an Acetabular reamer, and the plastic bowl is positioned using screws or bone cement. 
     The surgery typically requires one week of hospitalization due to the increased risk of infection. The recovery process is on average about 6 weeks, but even after this period the patient should not perform any physical activates that places large strain on the joint. 
     SUMMARY 
     An medical device for implantation in a hip joint for providing a joint surface is provided. The medical device comprises an artificial caput femur surface adapted to function as a bearing surface of the hip joint when in its functional position, and a fixating part, adapted to at least partially be placed inside of the femoral bone for fixating the artificial caput femur surface to the femoral bone, wherein said medical device comprises at least two parts adapted to be connected to each other in situ to form said artificial medical device. 
     According to one embodiment the at least two artificial hip joint surface parts are adapted to be mounted in situ to form a mounted medical device. 
     According to another embodiment, a first part of the at least two parts comprises a hip joint contacting surface, and a second part of the at least two parts comprises a hip joint contacting surface. The first and second parts are connected at an interconnecting area of the medical device, and the interconnecting area is a part of the contacting surface of the mounted medical device. 
     According to yet another embodiment the medical device further comprises a locking member adapted to lock the first part and the second part together after the first and second part has been connected into a mounted medical device. 
     At least one of the at least two parts could comprise a hip joint contacting surface, adapted to be in contact with an acetabulum or an artificial replacement therefor, and a femur contacting surface adapted to be in connection with the femoral bone of the patient. 
     The medical, according to any of the embodiments, could be frustum spherical. 
     According to one embodiment, the first artificial hip joint surface could comprise a first carrying surface, carrying weight in the hip joint. The first and second parts of the at least two parts could be adapted to be fixated to each other creating a first connection line in between themselves. The first connection line could at least partly be located within the first carrying surface. 
     The said at least two artificial hip joint surface parts, according to any of the embodiments, could be adapted to be introduced through a hole in the pelvic bone having a cross sectional area smaller than 530 mm2, or smaller than 380 mm2, or smaller than 250 mm2, or smaller than 180 mm2, or smaller than 110 mm2. 
     The locking member could according to one embodiment be a locking band adapted to encircle a portion of the femoral bone. 
     According to another embodiment the at least two parts have a distribution which is a part of a circle. 
     According to yet another embodiment, the mounted medical device displays a partly spherical shape being hollow, and could be adapted to be fixated to the femoral bone of the patient by at least partly surrounding a portion of the femoral bone. 
     According to yet another embodiment the locking member could be a locking band adapted to encircle the mounted medical device to further fixate the mounted medical device to the portion of the femoral bone. 
     The medical device, according to any of the embodiments herein, could be adapted to be inserted through a hole in the pelvic bone from the opposite side from acetabulum. The hole could have a diameter less than the largest diameter of the medical device, when the device is in its functional position in the hip joint. 
     According to yet another embodiment, the at least two artificial caput femur surface parts could be adapted to be inserted through a hole in the hip joint capsule, a hole which has a diameter less than the largest diameter of the medical device, when the device is in its functional position in the hip joint. 
     The at least two artificial caput femur surface parts could further be adapted to be inserted through a hole in the femoral bone, a hole which has a diameter less than the largest diameter of the medical device in its functional position in the hip joint. 
     At least one of said at least two parts, in any of the embodiments herein, could be a part adapted to serve as base part to which at least one additional part can be connected. 
     According to one embodiment, the medical device could comprises multiple ring shaped objects, said multiple ring shaped objects being adapted to connect to each other in situ, after insertion in a hip joint to form an artificial acetabulum surface. 
     According to yet another embodiment the medical device could further comprise a second artificial hip joint surface for replacing a second carrying surface, carrying weight in the hip joint. A third and fourth part of the at least two parts could be adapted to contact the first carrying surface, or an artificial replacement therefor during functional hip movements. The third and fourth parts could further be adapted to be fixated to each other creating a second connection line in between themselves, and wherein said second connection line is at least partly located within said second carrying surface. 
     The at least two parts, according to any of the embodiments herein, could be adapted to be mounted together creating a substantially even surface. 
     According to yet another embodiment the parts creates the substantially even surface along the connection line have a height difference of maximally 10 micrometer. 
     The parts creating the substantially even surface could have a height difference of maximally 100 micrometer or maximally 1 millimeter. 
     According to yet another embodiment the parts comprises a form fitted structure with a locking position for being mechanically fixated to each other. 
     According to yet another embodiment the medical device comprises a form fitted structure which further comprises a self-locking structure adapted to lock in the locking position. 
     The at least two parts could according to one embodiment comprise a structure adapted to enable the parts to slide in relation to each other. The two parts could further be adapted to, in the locking position, be substantially locked at least in all directions except the sliding direction and/or backwards thereof. 
     The form fitted structure could comprise a structure of the parts adapted to, when mounting them together, have at least one portion of at least one of the parts introduced into the other part, adapted to be introduced in at least two consecutive different directions and in the locking position adapted to be substantially locked at least in all directions except the last introduced direction and/or backwards thereof. 
     The at least two parts could according to yet another embodiment be adapted to be displaceable in relation to each other until they are positioned in a functional position inside of the hip joint in a predefined position, such that the medical device can function as a hip joint surface. 
     The at least two parts could according to one embodiment be adapted to be rotatably connected to each other in situ, and adapted to function as hip joint surface when the at least two parts have been connected in situ. 
     According to yet another embodiment, at least one of the at least two parts could comprise an elastic member. The medical device is could thus be adapted to be fixated to a caput femur or the pelvic bone by the elastic member exerting a squeezing force on the femoral bone or the pelvic bone. 
     An implantable medical device for treating hip joint osteoarthritis by providing a hip joint surface is further provided. The medical device comprises at least two artificial hip joint surface parts, which are adapted to be connected to each other to form the artificial hip joint surface during an operation for treating hip joint osteoarthritis. 
     According to one embodiment the medical device could be adapted to provide an artificial caput femur surface, and according to another embodiment the medical device could be adapted to provide an artificial acetabulum surface. It is also conceivable that the medical device is adapted to provide both an artificial caput femur surface and an artificial acetabulum surface. 
     Appearance 
     The at least two parts of the medical device could have a circular distribution or the least two parts could have a distribution which is a part of a circle for corresponding with the acetabulum, and/or the caput femur. The parts according to any of the embodiments herein could be made from the same material and could be adapted to be mounted inside of the hip joint during an operation. 
     According to one embodiment the medical device comprises at least one artificial caput femur surface and/or an artificial acetabulum surface, which displays a partly spherical shape being hollow, and through its shape being adapted to mechanically fixate the artificial caput femur surface to the caput femur, or an artificial replacement therefore, by at least partly surrounding the caput femur beyond a maximum diameter of the caput femur. 
     According to one embodiment the at least two artificial caput femur surface parts are adapted to be inserted through a hole in the pelvic bone from the opposite side from acetabulum of a human patient. The hole could have a diameter less than the largest diameter of the medical device in its functional position in the hip joint, for enabling a less invasive insertion of the medical device. 
     According to one embodiment at least one of said at least two parts is a part adapted to serve as base part to which at least one additional part can be connected. The base part could be located in the center in relation to said at least one additional part. 
     According to another embodiment the medical device comprises multiple ring shaped objects, being adapted to connect to each other after insertion in a hip joint to form an artificial acetabulum surface. 
     According to one embodiment the medical device defines a more than a hemisphere spherical shape. 
     The implantable medical device could comprise a first carrying surface, carrying weight in the hip joint, wherein said parts are adapted to be fixated to each other creating a first connection line in between themselves, and wherein said line at least partly involves said first carrying surface. However, it is equally conceivable that said line do not involve said first carrying surface. 
     According to yet another embodiment the implantable medical device further comprises a second artificial hip joint surface for replacing a second carrying surface, carrying weight in the hip joint. The second carrying surface is adapted to contact the first carrying surface or an artificial replacement therefore during functional hip movements, wherein said second parts are adapted to be fixated to each other creating a second connection line in between themselves, and wherein said line at least partly involves said second contacting surface. However, it is equally conceivable that said line do not involve said first carrying surface. 
     The parts along the connection line involving said carrying surface, could be adapted to be mounted together creating a substantially even surface which according to one embodiment has a height difference of maximally 10 micrometer, according to another embodiment has a height difference of maximally 100 micrometer and according to another embodiment has a height difference of maximally 1 millimeter. 
     According to one embodiment, the implantable medical device parts comprises a form fitted structure with a locking position for being mechanically fixated to each other. The form fitted structure could furthermore comprise a self-locking structure adapted to lock in said locking position. 
     According to one embodiment the medical device comprises a form fitted structure which comprises a structure of the parts adapted to, when mounting them together, have the parts sliding in relation to each other and in the locking position adapted to be substantially locked at least in all directions except the sliding direction and/or backwards thereof. 
     According to one embodiment the medical device comprises a form fitted structure which comprises a structure of the parts adapted to, when mounting them together, have at least one portion of at least one of the parts introduced into the other part and in the locking position adapted to be substantially locked at least in all directions except the introduced direction and/or backwards thereof. 
     According to one embodiment the medical device comprises a form fitted structure which comprises a structure of the parts adapted to, when mounting them together, have at least one portion of at least one of the parts introduced into the other part, adapted to be introduced in at least two consecutive different directions and in the locking position adapted to be substantially locked at least in all directions except the last introduced direction and/or backwards thereof. 
     The implantable medical could further comprise a locking member adapted to lock the structure in a locking position. The locking member could be adapted to lock the parts in the locking position keeping the parts mounted to each other. 
     According to another embodiment the locking member is adapted to lock the parts in said locking position by keeping said parts mounted to the human bone. The locking member according to any of the embodiments could comprise a splint and/or screw. 
     The locking member could be adapted to, in relation to the parts, be able to be; rotated, angled, introduced into or bent to lock said parts in said locking position. 
     The implantable medical device could further comprise a self locking member, adapted to lock in a self-locking position, which could be further assisted by a locking member, adapted to further lock in said self-locking position. 
     According to one embodiment the implantable medical device comprises a locking member, and the parts in the form fitted structure, comprises at least one portion of at least one of the parts adapted to be introduced into the other part, when mounted together in the hip joint in the locking position, and adapted to be substantially locked by the locking member. 
     The parts in the form fitted structure, according to any of the embodiments above, could comprise at least one flat surface each adapted to be mounted towards each other, when mounted together in the hip joint in the locking position, and adapted to be substantially locked by the locking member. 
     According to one embodiment the first contacting surface in the hip joint comprises three or more second parts adapted to be mechanically fixated to each other when implanted in said hip joint, after being introduced inside said hip capsule into said hip joint. 
     According to yet another embodiment of the medical device the second artificial surface for replacing the second contacting surface in the hip joint, comprises three or more second parts adapted to be mechanically fixated to each other when implanted in the hip joint, after being introduced inside the hip joint capsule into the hip joint. 
     The first artificial surface could comprise at least two layers mounted together, wherein one layer could comprise a flexible layer adapted to have at least one carrying layer mounted thereon. The carrying layer could comprise two or more parts mounted onto the flexible layer. 
     According to another embodiment of the medical device the second artificial surface, comprises at least two layers mounted together. 
     One layer could comprise a flexible layer adapted to have at least one carrying layer mounted thereon. The carrying layer could comprise two or more parts mounted onto the flexible layer. 
     The second artificial surface could be adapted to be introduced in the hip joint bent or rolled, and the parts of the carrying layer could be in a first position towards each other, and after being introduced inside said hip capsule into said hip joint, adapted to be unrolled or unbent, wherein said parts of said carrying layer are in a second position towards each other, adapted to create a carrying surface for replacing at least the part of said second contacting surface carrying weight in the hip joint, during functional movements of the hip joint. 
     The carrying layer according to any of the embodiments could comprise three or more parts mounted onto a flexible layer, and the parts of the carrying layer could be adapted to be form fitted, when said carrying layer is in said second position, to create a substantially even surface. The parts of the carrying layer could be glued to each other to keep the even surface. 
     Connection/Fixation 
     The two artificial hip joint surface parts, according to any of the embodiments above, could be adapted to be mechanically connected to each other using an element selected from a group consisting of: at least one screw, at least one splint, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, sprint, wire, a ball mounted into a cup being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, and/or other mechanical connecting members. 
     According to another embodiment the at least two parts could be adapted to mechanically connect to each other using self locking elements, which in turn could be assisted by adhesive or bone cement. 
     The medical device could comprise at least one elastic member for changing the shape of the medical device. 
     The two parts, according to any of the embodiments above, could be adapted to be connected to each other and to at least partly be displaceable in relation to each other when connected. 
     According to another embodiment of the medical device, the at least two displaceable parts could be adapted to be displaceable in relation to each other until they are positioned in a functional position inside of said hip joint comprising a predefined position, wherein the at least two parts get fixated such that the medical device can function as a hip joint surface. 
     The at least two parts could be rotatably connected to each other such that the medical device has a first state adapted for the insertion in the hip joint through a hole, and a second state adapted to enable the artificial hip joint surface to function as a hip joint surface, the medical device could further be adapted to alter between said first and second state by means of said rotatable connection. 
     According to one embodiment the medical device is adapted to be fixated to the caput femur or the pelvic bone using at least one element selected from a list consisting of: at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, and other mechanical connecting members. It is furthermore conceivable that the medical device is adapted to be fixated to the caput femur or the pelvic bone without penetration of the cortex of the caput femur, the femur bone or the pelvic bone e.g. by means of an elastic member exerting a squeezing force on said caput femur or said pelvic bone. However, the medical device could also be adapted to be fixated to the caput femur or the pelvic bone by penetration of the cortex of the caput femur, the femur bone or the pelvic bone. 
     The medical device could be adapted to be inserted through a hole in the pelvic bone, a hole in the femur bone, or a hole in the hip joint capsule. 
     It is furthermore conceivable that the medical device is adapted to provide at least one hip joint surface, when said hip joint is in its normal functional position or in a dislocated position. 
     In the embodiment where the medical device comprises an elastic member, the elastic member could be adapted for changing the largest diameter or largest cross-sectional distance of the medical device for insertion through a hole having a diameter smaller than said largest diameter or cross-sectional distance of said medical device, for enabling a less invasive insertion of the medical device. 
     According to one embodiment the at least two hip joint surface parts are adapted to be inserted through a hole in the pelvic bone from the opposite side from acetabulum of a human patient, the hole having a diameter less than the largest diameter of said medical device. 
     The medical device according to any of the embodiments could have the size of the largest diameter, largest radius or a largest cross-sectional distance being variable such that the medical device can be introduced through a hole having a cross sectional area smaller than 530 mm2 or smaller than 380 mm2 or smaller than 250 mm2 or smaller than 180 mm2 or smaller than 110 mm2. 
     Material 
     The medical device according to any one the embodiments herein could comprise at least one of the materials selected from a group consisting of: PTFE, Corian, Polyethylene based material, Titanium, Stainless steel, Wolfram, Other metal material, A combination of metal material, Carbon fiber, Boron, A combination of metal and plastic material, A combination of metal and carbon based material, A combination of carbon and plastic based material, Multi-material, wherein one material comprise a flexible material, Multi-material, wherein one material comprise an elastic material, Multi-material, wherein one material comprising more parts than the other at least one material, PE, and acrylic polymers. 
     The medical device could furthermore be adapted to be non-invasively lubricated after insertion in said hip joint, e.g. by means of an implantable lubrication system, or the medical device could comprise a self lubricating material. 
     Instrument 
     According to yet another embodiment the medical device could be adapted to be introduced into the hip joint using manual manipulation or a surgical instrument adapted therefore. The surgical instrument could in turn comprise a bend comprising at least one element selected from a list consisting of: a fixed angle, an adjustable angle, and a parallel displaced part or section. 
     Surgical/Laparoscopic Method 
     A method of treating a hip joint of a human patient by providing a medical device according to any of the embodiments above is further provided. The method could comprise the steps of: cutting the skin of the human patient, dissecting an area of the pelvic bone on the opposite side from said acetabulum, creating a hole in the dissected area passing through the pelvic bone and into the hip joint of the human patient, and providing the medical device to the hip joint, through the hole in the pelvic bone of the human patient. 
     A method of treating a hip joint of a human patient providing a medical device according to any of the embodiments above is further provided. The method could comprise the steps of: inserting a needle or a tube like instrument into the patient&#39;s body, using the needle or tube like instrument to fill a part of the patient&#39;s body with gas and thereby expanding a cavity within the body, placing at least two laparoscopic trocars in said cavity, inserting a camera through one of the laparoscopic trocars into the cavity, inserting at least one dissecting tool through one of the at least two laparoscopic trocars, dissecting an area of the pelvic bone on the opposite side from the acetabulum, creating a hole in the dissected area passing through the pelvic bone and into the hip joint of the human patient, and providing the medical device to the hip joint, through the hole in the pelvic bone of the human patient. 
     According to one embodiment the method comprises the steps of: cutting the skin of the human patient, dissecting an area of the hip joint, creating a hole in said dissected area, said hole passing into the hip joint of the human patient, and providing said medical device to the hip joint, through said hole. 
     A method of treating a hip joint of a human patient providing a medical device according to any of the embodiments above is further provided. The method could comprise the steps of: inserting a needle or a tube like instrument into the patient&#39;s body, using the needle or tube like instrument to fill a part of the patient&#39;s body with gas and thereby expanding a cavity within the body, placing at least two laparoscopic trocars in the cavity, inserting a camera through one of the laparoscopic trocars into the cavity, inserting at least one dissecting tool through one of the at least two laparoscopic trocars, dissecting an area of a hip joint, creating a hole in the dissected area passing into the hip joint, and providing the medical device to the hip joint, through the hole. 
     According to one embodiment, the method further comprises at least one of the following steps: dissecting an area of the hip joint, comprising the step of dissecting the pelvic bone on the opposite side from the acetabulum, creating a hole in said dissected area, comprises the step of creating a hole passing through the pelvic bone and into the hip joint of the human patient, and providing the medical device to the hip joint, comprises providing the medical device to the hip joint through the hole in the pelvic bone of the human patient. 
     Further Steps of the Operation 
     The methods according to any of the embodiments could further comprise the step of reaming the acetabulum and/or the caput femur, fixating the hip joint surface to the caput femur and/or to the acetabulum. The fixation could be performed by means of mechanical fixating members, bone cement or adhesive. 
     According to yet another embodiment the method further comprises the step of closing the hole by means of bone cement, a bone plug, or a prosthetic part. 
     According to yet another embodiment the method further comprises the step of placing a mould inside of said hip joint, and the step of injecting a fluid into said mould placed inside of the hip joint of the human patient, or placing at least one sealing member between the acetabulum and the caput femur, thus creating a sealed area between the acetabulum and the caput femur, and injecting a fluid into the sealed area. 
     After the methods are concluded the step of withdrawing the instruments and closing the skin of the human patient using sutures or staples is preferably performed. 
     Incision and Dissection 
     According to one embodiment the step of cutting the skin of the human patient is performed in the abdominal wall, the inguinal area and/or pelvic region of the patient. 
     According to the embodiments in which a cavity is made, the cavity can be located in the abdominal region the inguinal region and/or the pelvic region of the human patient. 
     The step of dissecting an area of the pelvic bone, described in the methods, could comprise dissecting an area of the abdominal cavity, an area between peritoneum and the pelvic bone, an area between the pelvic bone and the surrounding tissue, an area of the pelvic region and/or an area of the inguinal region. 
     A surgical method of implanting a medical device according to any one the embodiments is further provided, the method comprises the steps of: cutting the skin of a human patient, dissecting an area of the hip joint, dissecting and preparing the area of the first carrying surface, introducing the parts through the hip joint capsule into the hip joint, connecting, mechanically, the parts to each other, replacing the first carrying surface with the first artificial hip joint surface, and mounting the parts mounted together, in the functional hip joint. 
     A surgical method of implanting a medical device according to any one the embodiments is further provided, the method comprises the steps of: cutting the skin of a human patient, dissecting an area of the hip joint, dissecting and preparing the area of the second carrying surface, introducing the second parts through the hip joint capsule into the hip joint, connecting, mechanically, the second parts to each other, replacing the second contacting surface with the second artificial surface, comprising the second parts mounted together, in the functional hip joint. 
     An arthroscopic method of implanting the medical device according to any of the embodiments in a hip joint, the method comprises the steps of: inserting at least one needle or a tube like instrument into the patient&#39;s hip joint, using the needle or tube like instrument to fill the hip joint with a fluid, placing at least two arthroscopic trocars in the hip joint, inserting a camera through one of the arthroscopic trocars into the hip joint, inserting at least one dissecting tool through one of the at least two trocars, dissecting and preparing the area of the first carrying surface, introducing the parts through the hip joint capsule into the hip joint, connecting, mechanically, the parts to each other, replacing the first carrying surface with the artificial hip joint surface, mounting the parts together, in a functional hip joint. 
     The step of using the needle or tube like instrument to fill the joint with a fluid, could further comprise the steps of: circling the fluid with one inlet and one outlet from said hip joint. 
     Furthermore, an arthroscopic method of implanting a medical device according to any of the embodiments herein is provided. The method comprises the steps of: inserting at least one needle or a tube like instrument into the patient&#39;s hip joint, using the needle or tube like instrument to fill the hip joint with a fluid, placing at least two arthroscopic trocars in the hip joint, inserting a camera through one of the arthroscopic trocars into the hip joint, inserting at least one dissecting tool through one of the at least two trocars, dissecting and preparing the area of the second carrying surface, introducing the second parts through the hip joint capsule into the hip joint, connecting, mechanically, the second parts to each other, replacing the second carrying surface with the second artificial hip joint surface, mounting the second parts together, in a functional hip joint. 
     According to one embodiment the method could further comprise the step of circling the fluid with one inlet and one outlet from the hip joint. 
     Please note that any embodiment or part of embodiment, feature, method, associated system, part of system described herein may be combined in any way. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The embodiments are now described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  shows the hip joint in section, 
         FIG. 2  shows a lateral view of a conventional hip joint surgery, 
         FIG. 3  shows a medical device, according to one embodiment, being used in conventional surgery, 
         FIG. 4  shows a medical device, according to one embodiment, being used in conventional surgery, 
         FIG. 5  shows a medical device, according to one embodiment, being used in conventional surgery, 
         FIG. 6  shows a medical device, according to one embodiment, being used in conventional surgery, 
         FIG. 7  shows a medical device, according to one embodiment, being used in conventional surgery, 
         FIG. 8  shows a medical device, according to one embodiment, being used in conventional surgery, 
         FIG. 9  shows a medical device, according to one embodiment, being used in conventional surgery, 
         FIG. 10  shows a lateral view of the thigh region of the patient when the incision has been closed using sutures, 
         FIG. 11  shows an artificial caput femur surface being larger than equator frustum spherical, 
         FIG. 12 a    shows an artificial caput femur surface according to one embodiment, 
         FIG. 12 b    shows an artificial caput femur surface according to one embodiment, when fixated to the caput femur, 
         FIG. 13  shows cross-sectional views of the hip joint. 
         FIG. 14  shows an artificial caput femur surface according to one embodiment, 
         FIG. 15 a    shows an artificial caput femur surface according to a larger than equator frustum spherical embodiment, 
         FIG. 15 b    shows the artificial caput femur surface according to another embodiment, 
         FIG. 16 a -16 e    shows the artificial caput femur surface according to a yet another embodiment, 
         FIG. 17 a    shows the artificial caput femur surface according to yet another embodiment, 
         FIG. 17 b    shows the artificial caput femur surface according to 17a, in its folded state, 
         FIG. 18 a    shows the artificial caput femur surface according yet another embodiment, 
         FIG. 18 b    shows the artificial caput femur surface according to the embodiment of  18   a  when assembled, 
         FIG. 18 c    shows the artificial caput femur surface according to 18a,b with the connecting members enlarged, 
         FIG. 19 a    shows the artificial caput femur surface according to yet another embodiment, 
         FIG. 19 b    shows the artificial caput femur surface according to 19a in greater detail, 
         FIG. 19 c    shows the artificial caput femur surface according to 19a when assembled, 
         FIG. 20 a    shows a conceptual view of the function of the expandable caput femur surface, 
         FIG. 20 b    discloses the adjustable locking member to be mounted on the artificial acetabulum surface, 
         FIGS. 20 c -20 f    shows different embodiments of a locking member and an engagement member, 
         FIG. 20 g    shows a medical device and a locking member according to yet another embodiment, 
         FIG. 20 h    shows a medical device and a locking member according to yet another embodiment, 
         FIG. 20 i    shows a medical device with an integrated locking member according to one embodiment, 
         FIG. 20 j    shows a medical device with an integrated locking member according to another embodiment, 
         FIG. 20 k    shows an embodiment of a medical device and a mechanical fixating member, 
         FIG. 20 l    shows a first kit comprising three artificial caput femur surfaces and one locking member, 
         FIG. 20 m    shows a second kit comprising one artificial caput femur surfaces and three locking members, 
         FIG. 20 n    shows a third kit comprising three artificial caput femur surfaces and three locking members. 
         FIG. 21  shows a conceptual view of the function of the expandable caput femur surface, 
         FIG. 22 a    shows a conceptual view of the function of the expandable acetabulum surface, 
         FIG. 22 b    shows the hip joint in section when an artificial acetabulum surface has been provided, 
         FIG. 23  shows the assembly of a medical device, 
         FIG. 24  shows the assembly of a medical device, 
         FIG. 25  shows the assembly of a medical device, 
         FIG. 26  shows the assembly of a medical device, 
         FIG. 27   a,b,c  shows the assembly of a medical device, 
         FIG. 28   a,b,c  shows the assembly of a medical device, 
         FIG. 29   a,b,c  shows the assembly of a medical device, 
         FIG. 30   a,b,c  shows the assembly of a medical device, 
         FIG. 31 a    shows the providing of a first flexible layer onto the caput femur, 
         FIG. 31 b    shows the caput femur when a flexible layer has been provided, 
         FIG. 32 a    shown a medical device comprising multiple parts, 
         FIG. 32 b    shown a medical device comprising multiple parts, in further detail, 
         FIG. 33  shows the placing of a second stiff layer onto a first flexible layer, 
         FIG. 34  shows the hip joint when a second stiff layer has been placed onto a first flexible layer, 
         FIG. 35  shows the insertion of artificial hip joint surface parts in the surgical method, 
         FIG. 36  shows a step of the laparoscopic/arthroscopic method in further detail, 
         FIG. 37  shows different locations of the incisions made in the human body in the surgical method, 
         FIG. 38  shows different locations where small incisions can be made in the human body in the laparoscopic/arthroscopic method, 
         FIG. 39 a    shows the laparoscopic/arthroscopic method of operating the hip joint of a human patient, 
         FIG. 39 b    shows a lateral view in section of the laparoscopic/arthroscopic method, 
         FIG. 40  shows the hip joint in section when a hole is created in the pelvic bone, 
         FIG. 41  shows the hip joint in section when a small hole is created in the pelvic bone, 
         FIG. 42  shows the instrument that creates a hole in the pelvic bone according to a first embodiment, 
         FIG. 43  shows the instrument that creates a hole in the pelvic bone according to a first embodiment in further detail, 
         FIG. 44  shows the instrument that creates a hole in the pelvic bone according to a second embodiment, 
         FIG. 45  shows the instrument that creates a hole in the pelvic bone according to a third embodiment, 
         FIG. 46  shows the bone contacting organ according to a first embodiment, 
         FIG. 47  shows the bone contacting organ according to a second embodiment, 
         FIG. 48 a    shows the step of providing an artificial caput femur surface, 
         FIG. 48 b    shows the a section of the hip joint after the artificial caput femur surface has been provided, 
         FIG. 49  shows the expandable reamer, 
         FIG. 50  shows the expandable reamer in its folded state, 
         FIG. 51  shows the expandable reamer from underneath, 
         FIG. 52  shows the expandable reamer being used in the surgical or laparoscopic/arthroscopic method, 
         FIG. 53 a    shows an expandable artificial caput femur surface, according to the second embodiment, when travelling through a hole in the pelvic bone. 
         FIG. 53 b    shows an expandable artificial ca put femur surface, according to the second embodiment, when being placed on the caput femur. 
         FIG. 53 c    shows an expandable artificial caput femur surface, according to the second embodiment, when placed on the caput femur. 
         FIG. 54 a    show the insertion of artificial caput femur surface parts into the hip joint, 
         FIG. 54 b    shows the artificial caput femur surface parts after they have been connected inside of the hip joint forming an artificial caput femur surface, 
         FIG. 54 c    shows how the form of the artificial caput femur surface parts enables the connection of the artificial caput femur surface parts to form an artificial caput femur surface, 
         FIG. 54 d    shows a camera being inserted into the hip joint, 
         FIG. 55 a    shows the hip joint when a medical device comprising multiple parts is being provided, 
         FIG. 55 a    shows the hip joint when a medical device comprising multiple parts is being provided, in a top view, 
         FIG. 56  shows the human patient in section when a medical device adapted to create a hole in the pelvic bone is provided, 
         FIG. 57  shows the hip joint in section when a hole is being created in the pelvic bone, 
         FIG. 58  shows the hip joint in section when a surgical instrument for removing the caput femur is provided, 
         FIG. 59  shows the hip joint in section when a surgical instrument for removing the caput femur is positioned inside of the caput and collum femur, 
         FIG. 60  shows the removing of the caput femur through a hole in the femoral bone, 
         FIG. 61  shows the removing of a part of a piece of bone from the caput femur, 
         FIG. 62  shows the piece of bone being placed on the medical device, 
         FIG. 63  shows the medical device with the piece of bone being inserted through a hole in the pelvic bone, 
         FIG. 64  shows the hip joint in section when the medical device has been provided, 
         FIG. 65  shows the step of reaming the collum femur from a hole in the pelvic bone, 
         FIG. 66  shows the step of applying an adhesive to an area of the collum femur, 
         FIG. 67  shows the step of placing an artificial hip joint surface in the collum femur, 
         FIG. 68  shows the parts of a medical device according to another embodiment, 
         FIG. 69  shows the hip joint in section when a medical device has been provided, 
         FIG. 70  shows the placing of a prosthetic part in the hole in the pelvic bone, 
         FIG. 71  shows a section of the hip joint when a medical device has been fixated. 
         FIG. 72  shows a pre-mounted embodiment of the medical device, 
         FIG. 73  shows a pre-mounted embodiment of the medical device, when assembled, 
         FIG. 74  shows a pre-mounted embodiment of the medical device, 
         FIG. 75  shows a pre-mounted embodiment of the medical device, when assembled, 
         FIG. 76  shows a pre-mounted embodiment of the medical device, when being mounted in the collum femur, 
         FIG. 77  shows a pre-mounted embodiment of the medical device, when mounted in the collum femur, 
         FIG. 78  shows an artificial acetabulum surface when being inserted into a hip joint, 
         FIG. 79  shows an artificial acetabulum surface according to a first embodiment, 
         FIG. 80 a    shows an artificial acetabulum surface according to a second embodiment, 
         FIG. 80 b    shows an artificial acetabulum surface according to the second embodiment in further detail, 
         FIG. 80 c    shows the artificial acetabulum surface when assembled, 
         FIG. 81 a    shows an artificial acetabulum surface according to a third embodiment, 
         FIG. 81 b    shows an artificial acetabulum surface according to the third embodiment when assembled, 
         FIG. 81 c    shows the connection function of the artificial acetabulum surface according to the third embodiment, 
         FIG. 82 a    shows an artificial acetabulum surface according to a fourth embodiment, 
         FIG. 82 b    shows the function of the artificial acetabulum surface according to the fourth embodiment, 
         FIG. 82 c    shows an artificial acetabulum surface according to a fourth embodiment in its folded state, 
         FIG. 82 d    shows the connection function of the artificial acetabulum surface according to a fourth embodiment, 
         FIG. 83 a    shows an artificial acetabulum surface according to a fifth embodiment, 
         FIG. 83 b    shows an artificial acetabulum surface according to the fifth embodiment in its folded state, 
         FIG. 84 a    shows an instrument for inserting parts into a hip joint according to a first embodiment, 
         FIG. 84 b    shows an instrument for inserting parts into a hip joint according to a second embodiment, 
         FIG. 84 c    shows an instrument for inserting parts into a hip joint according to a third embodiment, 
         FIG. 85  shows a hip joint in section after an artificial caput femur surface and an artificial acetabulum surface have been provided, 
         FIG. 86  shows the hip joint in section when a medical device has been provided, in a first state, 
         FIG. 87  shows the hip joint in section when a medical device has been provided, in a second state, 
         FIG. 88  shows the hip joint in section when a medical device has been provided, in a first state, 
         FIG. 89  shows the hip joint in section when a medical device has been provided, in a second state, 
         FIG. 90  shows the medical device in section, 
         FIG. 91  shows an alternative embodiment of the medical device shown in  FIG. 88 , in a first state, 
         FIG. 92  shows an alternative embodiment of the medical device shown in  FIG. 88 , in a second state, 
         FIG. 93  shows the hip joint in section, when a medical device according to yet another embodiment is provided, in a first state, 
         FIG. 94  shows the hip joint in section, when a medical device according to yet another embodiment is provided, in a second state, 
         FIG. 95 a    shows the hip joint in section when a medical device comprising an elastic or rupture band has been provided, in a first state, 
         FIG. 95 b    shows the medical device of  FIG. 95 a   , in section, in a first state, 
         FIG. 96 a    shows the hip joint in section when a medical device comprising an elastic or rupture band is provided, in a second state, 
         FIG. 96 b    shows the medical device of  FIG. 19 a   , in section, in a second state, 
         FIG. 97  shows the hip joint in section, when a medical device according to yet another embodiment has been provided, in a first state, 
         FIG. 98  shows the hip joint in section, when a medical device according to yet another embodiment has been provided, in a second state, 
         FIG. 99  shows the hip joint in section, when a medical device according to yet another embodiment has been provided, in a first state, 
         FIG. 100  shows the hip joint in section, when a medical device according to yet another embodiment has been provided, in a second state, 
         FIG. 101  shows the hip joint in section when a medical device, according to an embodiment where the artificial acetabulum surface comprises elastic elements, has been provided, in a first state, 
         FIG. 102  shows the hip joint in section when a medical device, according to an embodiment where the artificial acetabulum surface comprises elastic elements, has been provided, in a second state, 
         FIG. 103  shows an alternative embodiment of the medical device shown in  FIG. 101 , 
         FIG. 104  shows an embodiment in which an artificial acetabulum surface has been fixated to the pelvic bone, and an artificial caput femur surface has been fixated to the caput femur, 
         FIG. 105  shows a hip joint in section when a mould is being inserted, 
         FIG. 106 a    shows the creation of a hole in the femoral bone, 
         FIG. 106 b    shows an instrument able to introduce objects into a hip joint through the femoral bone, 
         FIG. 106 c    shows the placing of a mould inside of the hip joint using an instrument that operates through the femoral bone, 
         FIG. 106 d    shows the hip joint in section after the placing of a mould inside of the hip joint using an instrument that operates through the femoral bone, 
         FIG. 107  shows the insertion of a first sealing member into a hip joint, 
         FIG. 108  shows the insertion of a second sealing member, 
         FIG. 109 a    shows the creation of a hole in the femoral bone, 
         FIG. 109 b    shows an instrument able to introduce objects into a hip joint through the femoral bone, 
         FIG. 109 c    shows the placing of a sealing member inside of the hip joint using an instrument that operates through the femoral bone, 
         FIG. 110 a    shows an instrument for insertion of a mould or a sealing member into a hip joint, 
         FIG. 110 b    shows the instrument for insertion of a mould or a sealing member into a hip joint in section, 
         FIG. 110 c    shows the instrument for insertion of a mould or a sealing member into a hip joint according to a second embodiment, 
         FIG. 111  shows the filling of a sealed area inside of the hip joint using an instrument that operates through the pelvic bone, 
         FIG. 112  shows the filling of a mould inside of the hip joint using an instrument that operates through the femoral bone, 
         FIG. 113  shows the filling of a sealed area inside of the hip joint using an instrument that operates through the femoral bone, 
         FIG. 114  shows a hip joint in section after a sealed area in the hip joint has been filled with a fluid, 
         FIG. 115  shows the insertion of fluid into an area of the hip joint, 
         FIG. 116  shows the closing of a hole in the hip joint using a bone plug, 
         FIG. 117  shows the fixation of a bone plug in the pelvic bone, 
         FIG. 118  shows a part for closing a hole in the pelvic bone having displaceable supporting members, 
         FIG. 119 a    shows a prosthetic part being used to close a hole in the pelvic bone, 
         FIG. 119 b    shows how sections of a prosthetic part is used as support against the edges of the hole in the pelvic bone, 
         FIG. 119 c    shows the insertion of a prosthetic part in the hole in the pelvic bone, 
         FIG. 120  shows how screws are being used to fixate a bone plug or a prosthetic part in the hole in the pelvic bone of a human patient, 
         FIG. 121  shows a cross-sectional view of the pelvic bone, 
         FIG. 122 a    shows how a supporting plate is being used to fixate a bone plug or a prosthetic part in the hole in the pelvic bone of a human patient, 
         FIG. 122 b    shows two bone plugs or prosthetic parts being fixated using a supporting plate, 
         FIG. 122 c    shows a section of the hip joint after two holes in the pelvic bone have been filled with a fluid, 
         FIG. 123 a    shows an injecting member adapted to inject a fluid into an area of the hip joint, 
         FIG. 123 b    shows an injecting member adapted to inject a fluid into an area of the hip joint when injecting a fluid, 
         FIG. 124  shows an injecting member in further detail, 
         FIG. 125 a    shows the step of suturing or stapling in the surgical method, 
         FIG. 125 b    shows the step of suturing or stapling in the laparoscopic/arthroscopic method. 
         FIG. 126  shows a frontal view of a patient when a lubricating system is provided, 
         FIG. 127  shows the hip joint and lubricating system in further detail, 
         FIG. 128  shows a circling lubricating system, 
         FIG. 129  shows a circling lubricating system, with filter. 
     
    
    
     DETAILED DESCRIPTION 
     Biocompatible material is to be understood as being a material with low level of immune response. Biocompatible materials are sometimes also referred to as biomaterials. Analogous is biocompatible metals a metal with low immune response such as titanium or tantalum. The biocompatible metal could also be a biocompatible alloy comprising at least one biocompatible metal. 
     Form fitting is to be understood as an element having a part or section which is adapted to enable a mechanical connection of said element to at least one other element using said part or section. Form fitted structure is a structure of an element which enables form fitting. 
     Elasticity is to be understood as a materials ability to deform in an elastic way. 
     Elastic deformation is when a material deforms under stress (e.g. external forces), but returns to its original shape when the stress is removed. A more elastic material is to be understood as a material having a lower modulus of elasticity. The elastic modulus of an object is defined as the slope of its stress-strain curve in the elastic deformation region. The elastic modulus is calculated as stress/strain, where stress is the force causing the deformation, divided by the area to which the force is applied; and strain is the ratio of the change caused by the stress. 
     Stiffness is to be understood as the resistance of an elastic body to deformation by an applied force. 
     Functional hip movements are to be understood as movements of the hip that at least partly correspond to the natural movements of the hip. 
     On some occasions the natural movements of the hip joint might be somewhat limited or altered after hip joint surgery, which makes the functional hip movements of a hip joint with artificial surfaces somewhat different than the functional hip movements of a natural hip joint. 
     The functional position of an implantable medical device or prosthesis is the position in which the hip joint can perform functional hip movements. 
     Functional hip joint is a hip joint that can perform functional hip movements either with or without an implanted medical device or prosthesis. 
     The contacting surfaces in any of the embodiments herein could comprise a ceramic material such as a Zirconium dioxide ceramic material. 
     In the following a detailed description of embodiments will be given. 
     In the drawing figures, like reference numerals designate identical or corresponding elements throughout the several figures. It will be appreciated that these figures are for illustration only and are not in any way restricting the scope. Thus, any references to direction, such as “up” or “down”, are only referring to the directions shown in the figures. Also, any dimensions etc. shown in the figures are for illustration purposes. 
       FIG. 1  shows the hip joint of a human patient in section. The hip joint comprises a caput femur  5  placed at the very top of collum femur  6  which is the top part of the femoral bone  7 . The caput femur is in connection with the acetabulum  8  which is a bowl shaped part of the pelvic bone  9 . Both the caput femur surface  10  and the acetabulum surface  11  is covered with articular cartilage  13  which acts as a cushion in the hip joint. In patients with hip joint osteoarthritis, this articular cartilage  13  is abnormally worn down due to a low grade inflammation. The hip joint is surrounded by the hip joint capsule  12  which provides support for the joint and hinders luxation. After conventional hip joint surgery, penetrating the hip joint capsule  12 , the capsule  12  is dramatically weakened due to the limited healing possibilities of its ligament tissue. By performing hip joint surgery without damaging the hip joint capsule  12  the patient can fully recover and place equal amount of strain on an artificial joint as is possible on a natural one. 
     Functional hip movements are to be understood as movements of the hip that at least partly correspond to the natural movements of the hip. On some occasions the natural movements of the hip joint might be somewhat limited or altered after hip joint surgery, which makes the functional hip movements of a hip joint with artificial surfaces somewhat different than the functional hip movements of a natural hip joint. 
     The functional position or normal functional position, of an implantable medical device or prosthesis is the position in which the hip joint can perform functional hip movements. The final position is to be understood as a functional position in which the medical device needs no further position change. 
       FIG. 2  shows a lateral view of a conventional hip joint surgery where an incision  112  is made in the tight  113  enabling the surgeon to reach the femoral bone  7  on which the caput femur  5  is located. 
       FIG. 3  shows the placing of an artificial caput femur surface  45  on the caput femur  5  in conventional surgery when the femoral bone has been removed from its position in the hip joint. 
       FIG. 4  shows the placing of an artificial caput femur surface  45  on the caput femur in conventional surgery. The artificial caput femur according to this embodiment comprises slits  49  and arms  50  making the structure of the artificial caput femur surface flexible for clasping the caput femur  5  and going beyond the maximum diameter of the caput femur  5 . Furthermore the artificial caput femur surface  45  can be inserted into a hip joint through a hole smaller than the full functional size of the artificial caput femur surface  45 , enabling a less invasive surgical procedure. 
       FIG. 5  shows the placing of an artificial caput femur surface  45  on the caput femur in conventional surgery. The artificial caput femur according to this embodiment comprises slits larger slits  49  and smaller arms making the structure of the artificial caput femur surface flexible for clasping the caput femur  5  and going beyond the maximum diameter of the caput femur  5 . 
     Furthermore the artificial caput femur surface  45  can be inserted into a hip joint through a hole smaller than the full functional size of the artificial caput femur surface  45 , enabling a less invasive surgical procedure. 
       FIG. 6  shows the placing of an artificial caput femur surface  45  on the caput femur in conventional surgery. The artificial caput femur surface  45  comprises multiple ring-shaped artificial caput femur surface parts  63 . Said multiple ring-shaped artificial caput femur surface parts  63  are adapted to be connected to each other to form an artificial caput femur surface  45   
       FIG. 7  shows the placing of an artificial caput femur surface  45  on the caput femur in conventional surgery. The artificial caput femur surface  45  comprises multiple parts  46  adapted to be connected to each other to form an artificial caput femur surface  45   
       FIG. 8  shows the placing of an artificial caput femur  45  in conventional surgery, the femoral bone  7  has been cut at the neck, the collum femur, and the neck is replaced by a prosthetic stem  1201  which also fixates the medical device in the femoral bone  7  by the prosthetic stem being fixated in the femoral bone  7  either with bone cement or without. An artificial acetabulum surface  65  is pre-mounted on the artificial caput femur  45 . The artificial acetabulum surface  65  is flexible by means of the artificial acetabulum surface  65  comprising slits  66 . The artificial acetabulum surface  65  is further fixated by means of a band, cord or wire  59  placed beyond the maximum diameter of the caput femur for securing the artificial acetabulum  65  to the artificial caput femur  45 . 
       FIG. 9  shows an artificial acetabulum surface  65  which has been placed in the acetabulum of a patient and fixated to the pelvic bone  9 . The artificial acetabulum  65  is flexible in its construction by the artificial acetabulum comprising slits  66  which enables the artificial acetabulum  65  to travel beyond the maximum diameter of the caput femur  5  and/or passing through a hole smaller than the full functional size of the artificial acetabulum surface  65  enabling a less invasive surgical procedure. 
       FIG. 10  shows a lateral view of the thigh region of a patient when the incision made to reach the hip joint have been closed by means of sutures  110 . 
       FIG. 11  shows an artificial caput femur surface  45  in section having a greatest cross-sectional distance  52  adapted to travel over and beyond the maximum diameter of the caput femur  5 . The maximum diameter of the caput femur  5  being positioned at a corresponding largest cross sectional distance  61  of the artificial caput femur surface A second distance  62  is the distance that the artificial caput femur surface  45  travels beyond the maximum diameter of the caput femur  5 . Said distance  62  is the beyond part of the artificial caput femur surface and is a part of the mechanical fixation of the artificial caput femur surface  45  to the caput femur  5 . 
       FIG. 12 a    shows an artificial caput femur surface according to a first embodiment, the artificial caput femur surface  45  is adapted to pass beyond the maximum diameter of the caput femur  5 . This enables a mechanical fixation using the form of said artificial caput femur surface  45 . In this embodiment the artificial caput femur surface  45  comprises at least one slit  49  adapted to make said artificial caput femur surface  45  flexible for traveling over and beyond the maximum diameter of the caput femur  5 . The construction could further be made flexible so that the size of the artificial caput femur surface  45  can vary to become smaller for insertion through a hole  18  in the pelvic bone  9  smaller than the full functional size of the artificial caput femur surface  45 . It is also conceivable that the artificial caput femur surface  45  comprises two or more artificial caput femur surface arms  50  which have a cross sectional distance  52  between each other. This cross sectional distance  52  is according to one embodiment shorter than the maximum diameter of the caput femur  5  enabling the mechanical fixation of the artificial caput femur surface  45  by means of said artificial caput femur surface arms  50 . For further fixation a band, cord or wire  59  can be placed around the artificial caput femur surface  45  beyond the maximum diameter of the caput femur  5 . The band, cord or wire  59  can be mechanically connected using a self locking member  60  for forming a ring-shaped element able to assist in the fixation of the artificial caput femur surface  45  to the caput femur  5 . 
       FIG. 12 b    shows the artificial caput femur surface  45  when fixated to the caput femur with the supporting band, cord or wire placed around the artificial caput femur surface  45  beyond the maximum diameter of the caput femur  5 . The arms may also be adapted to go into the bone of caput femur  5  to lock said artificial caput femur surface  45 . 
       FIG. 13  shows the hip joint in section, the hip joint has a collum femur  6 , having a first axial distribution leading to a caput femur  5 , the center axis L 1  of the caput femur  5  being the caput femur center axis L 1 , caput femur having a substantially ball shaped configuration with an outer maximum diameter  1203 , shown in the section A-A, substantially perpendicular to the caput femur center axis L 1 . The caput femur  5  is normally placed in a bowl shaped acetabulum  8 , having an opening, the bowl shaped acetabulum  8  has a second axial distribution with an acetabulum center axis L 2  from the center of the bottom of the acetabulum bowl  8  and following the center of the bowl towards the center of the opening of the bowl towards the caput femur  5 . The acetabulum bowl  8  has an inner maximum diameter  1202 , as shown in the section B-B, substantially perpendicular to the acetabulum center axis L 2 , wherein the caput femur center axis L 1  is in line with the acetabulum center axis L 2  in a special centered position when the caput femur  5  is: placed, aligned, centered and symmetrical, as shown in  FIG. 13 , in the acetabulum bowl  8  in the hip joint. The caput femur  5  and the acetabulum  8  have one hip joint surface each, placed towards and contacting each other, the hip joint surfaces carries weight in the hip joint. 
       FIG. 14  shows the artificial caput femur surface  45  according to a second embodiment, The shaft or screw placed in the middle of the artificial caput femur surface  45  serves as a mechanical attachment  44  penetrating the cortex of the caput femur  5  and fixating the artificial caput femur surface  45  to the caput femur  5 . However it is also conceivable that said shaft or screw is assisted or replaced with screws, welding, sprints, band, adhesive or some other mechanical connecting member. 
       FIG. 15 a    shows an artificial hip joint surface according to an embodiment where the artificial hip joint surface comprises an inner surface  906 , and an outer surface  907 . The inner surface has a first point  908   a , a second point  909   a , a third point  908   b , a fourth point  909   b , a fifth point  908   c , and a sixth point  909   c , all points located on different places along a length axis L 1  of said inner surface  906 , wherein: a first straight line  910   a , reaching from said first point  908   a  to said second point  909   a  is parallel to a second straight line  910   b  reaching from said third point  908   b  to said fourth point  909   b , which in turn is parallel to a third straight line  910   c  reaching from said fifth point  908   c  to said sixth point  909   c , wherein: said first and said third straight lines  910   a ,  910   c  are of equal length, and wherein said second straight line  910   b  is longer than said first  910   a  and said third  910   c  straight lines and positioned between said first  910   a  and said third  910   c  straight lines. The artificial hip joint surface is thereby passing beyond the maximum diameter of the of the artificial hip joint surface, which enables the artificial hip joint surface to clasp an element such as the caput femur  5 , an artificial caput femur surface or an artificial replacement for the caput femur. The artificial hip joint surface is curved in more than one direction, as shown with reference to L 1  and L 2  being lines following the curvature in perpendicular directions. 
       FIG. 15 b    shows the artificial caput femur surface  45  according to a third embodiment, in which said artificial caput femur surface  45  comprises at least one slit  49  enabling the construction of the artificial caput femur surface  45  to be flexible, thus enabling the largest diameter  51  to vary for insertion of said artificial caput femur surface  45  through a hole in the pelvic bone  9  smaller than the full functional size of said artificial caput femur surface  45 . According to this embodiment the artificial caput femur surface  45  further comprises artificial caput femur surface arms  50  located on the sides of said at least one slit  49 . The caput femur surface arms  50  can be made of a flexible material enabling the insertion through a hole  18  in the pelvic bone  9  smaller than the largest diameter  51  of said artificial caput femur surface  45  when in its full functional size. 
     According to one embodiment the artificial caput femur surface  45  of said third embodiment could be adapted to pass beyond the maximum diameter of the caput femur  5 . This enables a mechanical fixation using the form of said artificial caput femur surface  45 . In the embodiment where the artificial caput femur surface  45  travels beyond the maximum diameter of the caput femur  5  the construction can be made flexible so that the size of the artificial caput femur surface  45  can vary to become smaller for insertion through a hole  18  in the pelvic bone smaller than the full functional size of the artificial caput femur surface  45 , and have an opening adapter to travel over the caput femur  5  that can be larger that the same opening is in the full functional size of the artificial caput femur surface  45  enabling the artificial caput femur surface  45  to at least partly cover an area beyond the maximum diameter of caput femur  5  from the direction of the acetabulum  8 . According to a second embodiment the artificial caput femur surface  45  comprises two or more artificial caput femur surface arms  50  which have a cross sectional distance  52  between each other. This cross sectional distance  52  is according to one embodiment shorter than the maximum diameter of the caput femur  5  enabling the mechanical fixation of the artificial caput femur surface  45  by means of said artificial caput femur surface arms  50 . 
       FIG. 16   a,b,c,d,e  shows the artificial caput femur surface  45  according to a fourth embodiment, in which said artificial caput femur surface  45  comprises a first  53   a  and a second  53   b  section, as shown in  FIG. 16 b   . The first and second sections are displaceable in relation to each other. According to a first embodiment said first section  53   a  can be rotated in relation to said second section  53   b  so that said second section  53   b  travels underneath said first section  53   a  to create a displaced artificial caput femur surface  54 , as shown in  FIG. 16 c   , which is possible to insert into a hip joint of a human patient through a hole  18  being oval, or at least having an area smaller than the cross sectional area of the artificial caput femur surface  45  when in its full functional size 45, as shown in  FIG. 16 a   . According to this embodiment the two sections are connected to each other when the artificial caput femur surface  45  is returned to its full functional size using a mechanical form fitting  55 , as shown in  FIG. 16 e   . However it is also conceivable that said connection is assisted or replaced with screws, welding, sprints, band, adhesive or some other mechanical connecting member. 
       FIG. 17 a,b    shows the artificial caput femur surface  45  according to a fifth embodiment, in which said artificial caput femur surface  45  comprises four slits. The artificial caput femur surface  45  is flexible in its construction allowing the four artificial caput femur arms  50  to be folded towards the center axis of the artificial caput femur surface  45  thus allowing the artificial caput femur surface  45  to be inserted into a hip joint through a hole smaller than the full functional size of the artificial caput femur surface  45 . The artificial caput femur surface  45  according to this embodiment can be constructed to go beyond the maximum diameter of the caput femur  5 , in which case the construction with the slits  49  allows the artificial caput femur surface  45  to change to both a smaller and a larger size than said full functional size. 
       FIG. 17 b    shows the artificial caput femur surface  45  in section when said artificial caput femur surface arms  50  are folded for insertion through a hole  18  with an area smaller than the largest area of the artificial caput femur surface  45  when in its full functional size. 
       FIG. 18 a    shows the artificial caput femur surface  45  according to a sixth embodiment, in which said artificial caput femur surface  45  comprises multiple ring-shaped artificial caput femur surface parts  63 . Said multiple ring-shaped artificial caput femur surface parts  63  are adapted to be connected to each other to form an artificial caput femur surface  45 , shown in  FIG. 18 b   . According to one embodiment said artificial caput femur surface parts  63  are adapted to be connected to each other using mechanical connecting members  64   a,b . In  FIG. 18 c , 64 a    shows how an individual ring-shaped artificial caput femur surface part  63  can be connected to itself to form a continuous ring shape.  64   b  shows how an individual ring-shaped artificial caput femur surface part  63  connects to other ring-shaped artificial caput femur surface parts  63  to form an artificial caput femur surface  45 . The artificial caput femur surface  45  according to this embodiment can further be adapted to go beyond the maximum diameter of the caput femur  5 . 
       FIG. 19   a,b,c  shows the artificial caput femur surface  45  according to a sixth embodiment, in which said artificial caput femur surface  45  comprises multiple artificial caput femur surface parts  46 . Said multiple artificial caput femur surface parts  46  are adapted to be connected to an interconnecting artificial caput femur surface part  56  after insertion into a hip joint. The interconnecting artificial caput femur surface part, which serves as a base part  56 , comprises self locking connecting members  57 , shown in  FIG. 19 b   , that fits with corresponding self locking members  58  of the artificial caput femur surface parts  46 . The artificial caput femur surface has a substantially even surface which according to one embodiment has a height difference  1204  of maximally 10 micrometer, according to another embodiment has a height difference  1204  of maximally 100 micrometer and according to another embodiment has a height difference  1204  of maximally 1 millimeter. The artificial caput femur surface  45  can further be adapted to go beyond the maximum diameter of the caput femur  5 . 
     After mounting the at least two artificial hip joint surface parts on the caput femur in situ, according to some embodiments the parts need to be further fixated to the caput femur using a locking member. Embodiments of locking members in combination with artificial hip joint surface parts or portions are further disclosed beneath with reference to  FIGS. 20 a   - 20   n.    
       FIG. 20 a    shows an artificial caput femur surface  45  according to an embodiment in which the artificial caput femur surface comprises multiple movable portions  1224  connected to an interconnecting part  56  by operable joints  1205  placed along one side of the movable portions  1224 . The artificial caput femur surface is further fixated to the caput femur by locking member  59 , such as a band, cord or wire  59  placed beyond the maximum diameter of the caput femur  5 , after the movable portions  1224  have been placed in there functional position clasping the caput femur  5 . The section A-A shows a movable portion  1224  when not in its functional state. The movable portion being connected to an interconnecting part  56  through a movable member in form of a hinge  1205  allowing the movable portion to move for being able to clasp the caput femur  5  and/or changing the maximum diameter of the artificial caput femur surface for passing through a hole smaller than the maximum diameter of the caput femur surface in its functional state, in which case the movable member is moved in a direction towards the center of the artificial caput femur surface (not shown). 
       FIG. 20 b    discloses the adjustable locking member  59  to be mounted on the artificial caput femur surface  45 . The locking member  59  is a loop-shaped element having two ends  59   a ,  59   b  adapted to be mechanically connected using an engagement member  60 , thus forming a closed loop with a certain circumference. The locking member  59  can be made out of an elastic material which deforms under stress (e.g. external forces), but returns to its original shape when the stress is removed. 
     The artificial caput femur surface  45  comprises two or more artificial caput femur surface arms  50  which create a largest diameter  52 . To lock the artificial caput femur to the caput femur  5 , the locking member  59  is, when it is in an open state, pulled over the surface  45  until it at least reaches an area extending a distance D beyond the maximum diameter of the caput femur  5 . 
     The locking member  59  can also be pulled until it reaches and rests on surface arms  50 . When in its final position, the locking member ends  59   a ,  59   b  are mechanically connected by the engagement member  60 , and the artificial caput femur is held in place. 
       FIGS. 20 c -20 f    shows different embodiments of the locking member  59  and the engagement member  60 . 
     A first embodiment of a locking member  59  with engagement member  60  is disclosed in  FIG. 20 c   . The engagement member  60  comprises a first and a second part  60   a ,  60   b  arranged in the first and second locking member end  59   a ,  59   b , respectively. The first and second engagement member parts  60   a ,  60   b  have the shape of protrusions extending axially from the first and second locking member end, upwards and downward respectively. Thus forming a horizontally arranged gripping claw. The first engagement member part  60   a  has a cut-out in its lower surface and the second engagement member part  60   b  has a cut-out in its upper surface. The cut-outs are so arranged that they form an upper and a lower hook adapted to mechanically self connect by using the elasticity of the material and thus to form a loop with a certain circumference adapted to the diameter of the caput femur  5 . 
     In a second embodiment of the locking member  59 , shown in  FIG. 20 d   , the engagement member  60 ′ is arranged in one first and second end  59   a ,  59   b  of the locking member. In the first locking member end  59   a  one first engagement member part  60   a ′ in the form of a protrusion extending radially, towards the center of the loop is arranged. The first engagement member part  60   a  is adapted to engage with one corresponding second engagement member part  60   b  which is a protrusion arranged in the other second end  59   b  of the locking member extending radially, from the center of the loop. The protrusions together are forming an engagement member in the form of a vertically arranged gripping claw  60 ′. The circumference of the locking member can be adjusted by using more than one second engagement member parts  60   b  and arranging them at different distances from the second end  59   b  of the locking member. In the second embodiment in  FIG. 20 d    there are more than one, preferably between three and six, gripping claws  60   b ′ arranged on the second end  59   b  of the locking member  59 . The locking member  59  diameter can thus be adjusted. 
     A third embodiment of the locking member  59  is disclosed in  FIG. 20 e   . In one first end  59   a  of the locking member  59  there is a first engagement member part  60   a ″ in the form of a protrusion adapted to fit into a corresponding second engagement member part  60   a ″ in the form of a recess or a hole in the other second end  59   b  of the locking member  59 . It is also possible to have more than one hole so that the circumference of the locking member  59  is adjustable. 
     A forth embodiment of the locking member  59  is disclosed in  FIG. 20 f   . Here the first and second ends  59   a ,  59   b  of the locking member  59  are connected by using an engagement member  60 ′ comprising two pivotable first locking parts  60   a   1 ′″,  60   a   2 ′″ and one second locking part  60   b ′″. The first locking part  60   a   1 ′ is pivotably attached both to the first end  59   a  of the locking member  59  and to the second locking part  60   a   2 ′″. The second locking part  60   a   2 ″″ is attached to the first locking part  60   a   1 ′″ in an engagement point arranged between the outer ends of the first locking part  60   a   1 ′, preferably in a point arranged substantially in the middle of the first locking part  60   a   1 ′″. The second locking part  60   a   2 ′″ is also adapted to engage with a protruding part  60   b ′″ arranged in the second end  59   b  of the locking member  59 . When the second locking part  60   a   2 ′″ is engaged with the protruding part  60   b ′, the first and second end of the locking member  59   a ,  59   b  is locked together forming a closed loop with a first circumference. The first and second locking member ends  59   a ,  59   b  can be pulled together forming a closed loop with a second circumference firmly enclosing the artificial caput femur and locking it to the caput femur  5 . The first and second locking member ends  59   a ,  59   b  are pulled together by pivoting the first locking part around its engagement point in the first end  59   a  of the locking member. The first and second locking member ends  59   a ,  59   b  can be arranged either overlapping each other or being arranged end to end when locked together, thus forming a loop with the second circumference. 
       FIG. 20 g    shows yet another embodiment of the locking member, in which the locking member does not encircle the caput femur surface  45  completely, thus leaving a distance  2101  in which there is no locking member. According to the embodiment shown in  FIG. 20 g    the locking member  59  clamps the artificial caput femur surface by the locking member being made from an elastic material, such as stainless steel. The construction with locking member enables the artificial caput femur surface to be made from a more resilient material, for allowing the artificial caput femur surface to pass over the larger parts of the caput femur. One advantage with the embodiment shown in  FIG. 20 g    is that the locking member  59  does not have to be as elastic as the locking members that totally encircles the caput femur, to still be mountable by the surgeon in situ. 
       FIG. 20 h    shows a locking member according to an embodiment similar to the embodiment described previously, with reference to  FIG. 20 g   . However, according to the embodiment shown in  FIG. 20 h   , the locking member  59  comprises a hinge  2105  placed at the center of the locking member  59  to which two portions  2106   a ,  2106   b  of the locking member are connected. In connection to the hinge a locking device is placed comprising an male  2108  part adapted to connect to a female part  2109 , thus creating a locking position. The locking member in the locking position clasps the artificial caput femur surface  45  and thus further fixates the artificial caput femur surface  45  to the caput femur. The embodiment of  FIG. 20 h   , with the hinge, enables the locking member to be made from a less elastic material than is necessary in embodiments where the entire locking member is made from a single piece of material (such as the embodiment described with reference to  FIG. 20 g   ). The embodiment could further reduce the force needed to mount the locking member  59  onto the artificial caput femur  45  in situ. 
       FIG. 20 i    shows a locking member  59  according to yet another embodiment, in which the locking member  59  comprises a first and second unit  2102   a ,  2102   b  placed at two sides of a slit  49  in the artificial caput femur surface  45 . The first unit  2102   a  comprises a male part  2103  which is insertable into a female part  2104  of the second unit  2102   b , in which it locks and thus places the slit  49  in a more closed state for fixating the artificial caput femur  45  surface to the caput femur. 
       FIG. 20 j    shows the medical device according to an embodiment in which the locking member  59  is placed centrally in the top of an embodiment of the artificial caput femur surface  45 , in which the artificial caput femur surface is dividable into two halves. The locking member comprises, in accordance with the embodiment shown with reference to  FIG. 20 i   , a first and second unit  2102   a ,  2102   b , wherein said first unit comprises a male part  2103  adapted to lock inside of a female part housed in the second unit. 
       FIG. 20 k    shows an embodiment of the locking member  59  in which the locking member  59  is adapted to travel from a first point of the artificial caput femur surface  45  through the bone of caput and/or collum femur and to a second point of the artificial caput femur surface  45 . This embodiment could enable the locking member to fixate the artificial caput femur surface  45  to the caput femur by exerting a squeezing force and thus clamping the caput femur, and/or by the locking member  59  being inside the bone actually creating a mechanical lock thereby. According to the embodiment shown in  FIG. 20 k    the locking member  59  goes from one point of the artificial caput femur surface  45  to another point on the artificial caput femur surface  45 , through the bone of the caput/collum femur. However in other embodiments (not shown) the locking member goes from a point of the artificial caput femur surface and into the bone of caput/collum femur, in these embodiments the locking members could be mechanical fixating members, such as orthopedic screws. 
       FIG. 20 l    shows a kit according to a first embodiment in which the kit comprises three different sizes of artificial caput femur surfaces  45   a,b,c , which could be chosen on the basis of the particular patient, an a locking member  59  with several states which thus could be tightened around the different artificial caput femur surfaces  45   a,b,c  to fit the particular patient. 
       FIG. 20 m    shows a kit according to a second embodiment in which the kit comprises one artificial caput femur surface  45  and three different sizes locking member  59   a,b,c  which thus can be placed encircling the artificial caput femur surface  45  and be chosen for the particular femoral bone of a particular patient. 
       FIG. 20 n    shows a kit according to a second embodiment in which the kit comprises three different sizes of artificial caput femur surfaces  45   a,b,c , which could be chosen on the basis of the particular patient, and three different sizes of locking members  59   a,b,c  which thus can be placed encircling the artificial caput femur surface  45  and be chosen for the particular femoral bone of a particular patient. 
     The kit solutions enables the orthopedic surgeon to choose a suitable medical device when the caput femur is exposed, since determining the exact size and shape of the caput femur is very hard from merely images created from outside of the body. 
       FIG. 21  shows a conceptual view wherein the artificial caput femur surface  45 , according to any of the embodiments herein, has a diameter or cross-sectional distance d 1  small enough to enable said artificial caput femur surface  45  to travel through a hole  18  in the pelvic bone  9 . After the artificial caput femur surface  45  has traveled through the hole  18  in the pelvic bone  9  the artificial caput femur surface  45  is expanded such that the diameter or cross-sectional distance d 2  is large enough to travel over the caput femur  5 . Finally the artificial caput femur surface  45  is positioned on the caput femur  5 , in this state the diameter d 3  or cross-sectional distance is smaller than the largest diameter of the caput femur  5 , which mechanically attaches the artificial caput femur surface  45  to the caput femur  5 . d 3  is the normal state cross sectional distance of the medical device, i.e. the cross sectional distance that the medical device has when the medical device is in its functional position. This figure may also in an alternative embodiment show the artificial acetabulum surface mounted onto caput femur or an artificial replacement therefore with the same locking principle. 
       FIG. 22 a    shows a conceptual way wherein the artificial acetabulum surface  65  has a diameter or cross-sectional distance d 1  small enough to enable said artificial acetabulum surface  65  to travel through a hole  18  in the pelvic bone  9 . After the artificial acetabulum surface  65  has traveled through the hole  18  in the pelvic bone  9  the artificial acetabulum surface is expanded such that the diameter or cross-sectional distance d 2  is large enough to hinder the artificial acetabulum surface  65  from traveling through the hole  18  in the pelvic bone  9  as shown in  FIG. 22   b.    
       FIG. 23  shows the medical device according to an embodiment where the medical device comprises an artificial caput femur  45 , a fixating member  608 , and a stabilizing member  612  adapted to stabilize the medical device from the outside of the collum femur  6 , substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6  through the stabilizing member being placed in contact with the surface of a section  610  on the collum femur  6 . The stabilizing member  612  and the fixating member  608  could be fixated to the collum femur  6  by means of an adhesive  614  or bone cement. The stabilizing member  612  is made from an artificial material such as a biocompatible metal, (e.g. titanium or tantalum), or a biocompatible polymer or ceramic material. The medical device comprises two parts which are adapted to be interconnected to form an interconnected medical device. The first part of the medical device comprises a first part of the fixating member  608 ′, and a first part of the caput femur surface  45 ′. The second part of the medical device comprises a second part of the fixating member  608 ″, and a second part of the caput femur surface  45 ″. The parts are adapted to be connected to each other by a sliding dovetail joint. The first part of the medical device comprises a dovetail groove  1207  which matches the dovetail section  1206  of the second part of the medical device. The two parts can be interconnected to form the medical device, before or during a surgical procedure, preferably the parts are jointed during the surgical procedure since this enables the parts to be introduced into the hip joint through a hole smaller than a hole which through which the interconnected medical device could pass. The cross-section A-A shows the fixating part and the artificial caput femur  45 , when they are interconnected by means of the sliding dovetail  1206 ,  1207 . 
       FIG. 24  shows the medical device comprising an artificial caput femur  45  and a prosthetic stem  1201 . The medical device comprises two parts each comprising a part of the prosthetic stem  1201 ′, 1201 ″ and the artificial caput femur surface  45 ′, 45 ″. The medical device is adapted to be interconnected by multiple sliding dovetail joints  1206 , 1207 , wherein dovetail grooves  1207  in the second part of the medical device matches the dovetail sections  1206  of the first part of the medical device. The cross-section A-A shows the prosthetic stem of the first part  1201 ′ having a dovetail section  1206  and the prosthetic stem of the second part having a dove tail groove  1207 . 
       FIG. 25  shows the medical device according to an embodiment where the medical device comprises an artificial caput femur  45 , a fixating member  608 , and a stabilizing member  612  adapted to stabilize the medical device from the outside of the collum femur  6 , substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6  through the stabilizing member being placed in contact with the surface of a section  610  on the collum femur  6 . The medical device comprises two parts which are adapted to be interconnected to form an interconnected medical device. The first part of the medical device comprises a first part of the fixating member  608 , and a first part of the caput femur surface  45 . The second part of the medical device comprises a second part of the fixating member  608 ″, and a second part of the caput femur surface  45 ″. The parts are adapted to be connected to each other by a construction with pins  1209  and grooves  1208  matching each other. The first part of the medical device comprises the grooves  1209  which matches the pins  1208  of the second part of the medical device. The two parts can be interconnected to form the medical device, before or during a surgical procedure, preferably the parts are jointed during the surgical procedure since this enables the parts to be introduced into the hip joint through a hole smaller than a hole which through which the interconnected medical device could pass. The pins  1208  and grooves  1209  are secured by an elongated member  1212 , which could be flexible, such as a wire, or stiff, such as a pin, The elongated member  1212  is adapted to be inserted into a hole  1210  of the pins  1208  and a hole  1211  of the first part of the medical device, thereby securing the pins in the grooves  1211 . The cross-section A-A shows the fixating parts  608 ′, 608 ″ of the medical device with the elongated member  1212  placed in the hole  1211  in the medical device and the hole  1210  in the pins  1208 . The elongated member comprises an end portion  1213  having a flat upper surface adapted to form part of the artificial caput femur surface  45 . 
       FIG. 26  shows the medical device comprising an artificial caput femur  45  and a prosthetic stem  1201 . The medical device comprises two parts each comprising a part of the prosthetic stem  1201 ′, 1201 ″ and the artificial caput femur surface  45 ′, 45 ″. The parts are adapted to be connected to each other by a construction with pins  1208  and grooves  1209  matching each other. The first part of the medical device comprises the grooves  1209  which matches the pins  1208  of the second part of the medical device. The two parts can be interconnected to form the medical device, before or during a surgical procedure, preferably the parts are jointed during the surgical procedure since this enables the parts to be introduced into the hip joint through a hole smaller than a hole which through which the interconnected medical device could pass. The pins  1208  and grooves  1209  are secured by an elongated member  1212 , which could be flexible, such as a wire, or stiff, such as a pin, The elongated member  1212  is adapted to be inserted into a hole  1210  of the pins  1208  and a hole  1211  of the first part of the medical device, thereby securing the pins in the grooves  1211 . The cross-section A-A shows the prosthetic stem parts  1201 ′, 1201 ″ of the medical device with the elongated member  1212  placed in the hole  1211  in the medical device and the hole  1210  in the pins  1208 . The elongated member comprises an end portion  1213  having a flat upper surface adapted to form part of the artificial caput femur surface  45 . 
       FIG. 27 a    shows the medical device comprising an artificial caput femur  45  and a prosthetic stem  1201 . The medical device comprises two parts each comprising a part of the prosthetic stem  1201 ′, 1201 ″ and the artificial caput femur surface  45 ′, 45 ″. The parts are adapted to be connected to each other by a construction with pins  1214  and holes  1215  matching each other. The first part of the medical device comprises the holes  1215  which are adapted to receive the pins  1214  in a first direction and thereafter lock the pins in the holes in a second direction. The two parts can be interconnected to form the medical device, as shown in  FIG. 27 b   , before or during a surgical procedure, preferably the parts are jointed during the surgical procedure since this enables the parts to be introduced into the hip joint through a hole smaller than a hole which through which the interconnected medical device could pass. The cross section A-A of  FIG. 27 c    shows a pin  1214  in a hole  1215  after it firstly has been introduced in one direction and secondly been pushed to the side to lock the pin  1214  in the hole. 
       FIG. 28 a    shows the medical device according to an embodiment where the medical device comprises an artificial caput femur  45 , a fixating member  608 , and a stabilizing member  612  adapted to stabilize the medical device from the outside of the collum femur  6 , substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6  through the stabilizing member being placed in contact with the surface of a section  610  on the collum femur  6 . The medical device comprises two parts which are adapted to be interconnected to form an interconnected medical device, as shown in  FIG. 28 b   . The first part of the medical device comprises a first part of the fixating member  608 ′, and a first part of the caput femur surface  45 ′. The second part of the medical device comprises a second part of the fixating member  608 ″, and a second part of the caput femur surface  45 ″. The parts are adapted to be connected to each other by a construction with pins  1216  and holes  1217  matching each other. The first part of the medical device comprises the holes  1217  which are adapted to receive the pins  1216  in a first direction and thereafter lock the pins  1216  in the holes  1217  in a second direction. The two parts can be interconnected to form the medical device, before or during a surgical procedure, preferably the parts are jointed during the surgical procedure since this enables the parts to be introduced into the hip joint through a hole smaller than a hole which through which the interconnected medical device could pass. The cross section A-A, of  FIG. 28 c   , shows a pin  1216  in a hole  1217  after it firstly has been introduced in one direction and secondly been pushed to the side to lock the pin  1216  in the hole  1217 . 
       FIG. 29 a    shows the medical device comprising an artificial caput femur  45  and a prosthetic stem  1201 . The medical device comprises two parts each comprising a part of the prosthetic stem  1201 ′, 1201 ″ and the artificial caput femur surface  45 ′, 45 ″. The parts are adapted to be connected to each other by a construction with a pin  1218  and a hole  1219  matching each other. The first part of the medical device comprises the hole  1219  which are adapted to receive the pin  1218  in a first direction and thereafter lock the pin in the hole in a second direction, by turning the first and second parts in relation to each other. The two parts can be interconnected to form the medical device, as shown in  FIG. 29 b   , before or during a surgical procedure, preferably the parts are jointed during the surgical procedure since this enables the parts to be introduced into the hip joint through a hole smaller than a hole which through which the interconnected medical device could pass. The cross section A-A of  FIG. 29 c    shows a pin  1218  in a hole  1219  after it firstly has been introduced in one direction and secondly been turned to lock the pin  1218  in the hole  1219 . 
       FIG. 30 a    shows the medical device according to an embodiment where the medical device comprises an artificial caput femur  45 , a fixating member  608 , and a stabilizing member  612  adapted to stabilize the medical device from the outside of the collum femur  6 , substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6  through the stabilizing member being placed in contact with the surface of a section  610  on the collum femur  6 . The medical device comprises two parts which are adapted to be interconnected to form an interconnected medical device, as shown in  FIG. 30 b   . The first part of the medical device comprises a first part of the fixating member  608 ′, and a first part of the caput femur surface  45 ′. The second part of the medical device comprises a second part of the fixating member  608 ″, and a second part of the caput femur surface  45 ″. The first part of the medical device comprises a hole  1221  which are adapted to receive a pin  1220  in a first direction and thereafter lock the pin  1220  in the hole  1221  in a second direction, by turning the first and second parts in relation to each other. The two parts can be interconnected to form the medical device, as shown in  FIG. 30 b   , before or during a surgical procedure, preferably the parts are jointed during the surgical procedure since this enables the parts to be introduced into the hip joint through a hole smaller than a hole which through which the interconnected medical device could pass. The cross section A-A of  FIG. 30 c    shows a pin  1220  in a hole  1221  after it firstly has been introduced in one direction and secondly been turned to lock the pin  1220  in the hole  1221 . 
     The parts of the medical device according to any of the embodiments could have a size of the largest diameter, largest radius or a largest cross-sectional distance such that the medical device can be introduced through a hole having a cross sectional area smaller than 530 mm2 or smaller than 380 mm2 or smaller than 250 mm2 or smaller than 180 mm2 or smaller than 110 mm2. 
       FIG. 31 a    shows an embodiment in which a flexible first layer  1222  is applied onto the caput femur  5 . The flexible first layer  1222  is adapted to serve as a layer for fixation of a second stiff layer, acting as an artificial acetabulum surface  45 . The flexible first layer  1222  could for example be fixated to the caput femur  5  using an adhesive. 
       FIG. 31 b    shows the hip joint with the caput femur  5 , when the flexible first layer  1222  has been applied thereon. The flexible first layer  1222  can further be adapted to go beyond the maximum diameter of the caput femur  5 . 
       FIG. 32 a    shows an example of a stiff artificial caput femur surface  45  comprising multiple artificial caput femur surface parts  46 . The multiple artificial caput femur surface parts  46  are adapted to be connected to an interconnecting artificial caput femur surface part  56  after insertion into a hip joint. The interconnecting artificial caput femur surface part  56 , which serves as a base part, comprises self locking connecting members  57 , shown in  FIG. 32 b   , that fits with corresponding self locking members  58  of the artificial caput femur surface parts  46 . The artificial caput femur surface parts  46  create an artificial caput femur surface  45  when connected to each other. The self locking members  57 , 58  can be assisted or replaced by screws, welding, sprints, band, adhesive or some other mechanical connecting member. The artificial caput femur surface  45  according to this embodiment can further be adapted to go beyond the maximum diameter of the caput femur  5 . 
       FIG. 33  shows the parts being applied to the caput femur  5  with the flexible first artificial layer  1222  placed thereon. The flexible first layer  1222  could be adapted to even-out the surface of the caput femur  5  for achieving a better fixation of the stiff second layer, acting as an artificial caput femur surface  45 , or to act as a resilient member when the hip joint is in its functional position for absorbing shocks placed on the hip joint. 
       FIG. 34  shows the caput femur  5  when the stiff artificial caput femur surface  45  is completed and fixated on top of the first flexible layer  1222 . The stiff layer is preferably made of a hard material for resisting the wear that is created by the connection with the acetabulum  8 , or an artificial replacement therefore. The stiff second layer  45  could be fixated to the first flexible layer  1222  using an adhesive, form fitting or a mechanical fixation element. The second stiff layer  45  according to this embodiment can further be adapted to go beyond the maximum diameter of the caput femur  5 . 
       FIG. 35  shows the artificial hip joint surface parts  48  according to any of the embodiments being inserted through an incision according to a surgical method. According to a first embodiment the artificial hip joint surface parts  48  are artificial caput femur surface parts  46 , adapted to be connected to each other after the insertion to form an artificial caput femur surface  45 . 
       FIG. 36  shows the artificial hip joint surface parts  48  according to any of the embodiments being inserted through laparoscopic/arthroscopic trocars  33   a,b,c , through a small incision according to a laparoscopic/arthroscopic method. According to a first embodiment the artificial hip joint surface parts  48  are artificial caput femur surface parts  46 , adapted to be connected to each other after the insertion to form an artificial caput femur surface  45 . 
     A surgical and laparoscopic/arthroscopic method of treating hip joint osteoarthritis by providing a hip joint surface through the pelvic bone of a human patient from the opposite side from acetabulum is further provided. Said method will now be described in further detail. 
       FIG. 37  shows a frontal view of the body of a human patient. A surgical method of operating the hip joint from the opposite side from acetabulum  8  is according to a first embodiment performed starting with an incision  1  in the abdominal wall of the human patient. The incision  1  passes through the abdominal wall, including peritoneum in to the abdomen of the human patent. In a second preferred embodiment the incision  2  is conducted through the abdominal wall and into the pelvic area, below the peritoneum abdominal sac. According to a third embodiment the incision  3  is performed just between Illium of the pelvis bone and the surrounding tissue, an incision  3  which could enable the pelvic bone  9  to be dissected with very little penetration of fascia and muscular tissue. According to a fourth embodiment the incision  4  is made in the inguinal region. In all of the four embodiments the tissue surrounding the pelvic bone  9  in the area opposite to acetabulum  8  is removed or penetrated or divided or moved away which enables the surgeon to reach the pelvic bone  9 . It is obvious that the methods described may both be combined or altered reaching the same goal to dissect the pelvic bone  9  on the opposite side of the acetabulum  8 . 
       FIG. 38  shows a frontal view of the body of a human patient. A laparoscopic/arthroscopic method of operating the hip joint, from the opposite side from acetabulum  8  is according to a first embodiment performed starting with making small incisions  14  in the abdominal wall of the human patient. The small incisions enable the surgeon to insert laparoscopic/arthroscopic trocars into the abdomen of the human patient. 
     According to the first embodiment the incisions  14  passes through the abdominal wall, and peritoneum in to the abdomen of the human patent. According to a second preferred embodiment the small incisions  15  is conducted through the rectus abdominis or on the side thereof and in to the pelvic area, below peritoneum. According to a third embodiment the small incisions  16  is performed just between Illium of pelvis and the surrounding tissue, an incision  16  which could enable the pelvic bone to be dissected with very little penetration of fascia and muscular tissue. According to a fourth embodiment the incision  17  is made in the inguinal region. In all of the four embodiments the tissue surrounding the pelvic bone  9  in the area opposite to acetabulum  8  is removed or penetrated or divided or moved away which enables the surgeon to reach the pelvic bone  9 . 
       FIG. 39 a    shows a frontal view of the body of a human patient, illustrating the laparoscopic/arthroscopic method of operating the hip joint from the opposite side from acetabulum  8 . The hip joint comprises the acetabulum  8  and the caput femur  5 . The small incisions  14  in the abdominal wall of the human patient allows the insertion of laparoscopic/arthroscopic trocars  33   a,b,c  into the body of the patients. Whereafter one or more camera  34 , a surgical instrument adapted to create a hole in the pelvic bone  35 , or instruments  36  for dissecting, introducing, placing, connecting, attaching, creating or filling prosthesis or prosthetic parts, can be inserted into said body through said laparoscopic/arthroscopic trocars  33   a,b,c.    
       FIG. 39 b    shows a lateral cross-sectional view of the body of a human patient, with the hip joint shown in section in further detail. The hip joint comprises a caput femur  5  placed at the very top of collum femur  6  which is the top part of the femoral bone  7 . The caput femur  5  is in connection with the acetabulum  8  which is a bowl shaped part of the pelvic bone  9 . Laparoscopic/arthroscopic trocars  33   a,b,c  is being used to reach the hip joint  39  with one or more camera  34 , a surgical instrument adapted to create a hole in the pelvic bone  35 , or instruments  36  for dissecting, introducing, placing, connecting, attaching, creating or filling prosthesis or prosthetic parts. 
     After dissecting the pelvic bone  9  a hole  18  is created in the bone  9 , shown in  FIG. 19 . The hole  18  passes through the pelvic bone  9  from the opposite side from acetabulum  8  and into the hip joint  19 . 
       FIG. 40  shows the hole  18  in the pelvic bone  9  according to a first embodiment, the hole  18  is large which allows prosthesis to pass through said hole  18  in their full functional size. According to a second embodiment the hole  20  created in the surgical or laparoscopic/arthroscopic method is much smaller as shown in  FIG. 41  allowing the surgical instrument creating the hole to be smaller, and thus the incision and dissection performed in the human body. 
       FIG. 41  shows a surgical instrument for creating a hole  18 ,  20  in the pelvic bone  9   a  according to a first embodiment. The surgical instrument comprises a driving member  21   a, b . The driving member  21   a,b  could be a shaft, a rod, a belt, a chain or any other element suitable for transferring force or torque. The surgical instrument also comprises a bone contacting organ  22  which is adapted to create the hole  18 ,  20  in the pelvic bone  9 . The bone contacting organ  22  could have a sawing, drilling or milling effect using sharp objects; it is furthermore conceivable that said bone contacting organ  22  creates a hole using water, abrasive fluids, laser or radiation. The surgical instrument also comprises an operating device  23   a  adapted to operate the driving member  21   a,b . The operating device could comprise an electrical, mechanical, pneumatic or magnetic motor and it could be adapted to create a rotating, oscillating, vibrating or repetitive movement. The operation device may include a source of ultrasound, radiation, laser or water. 
       FIG. 42  shows a surgical instrument that further comprises a parallel displaced part or section  26 . The parallel displaced part or section  26  improves the reach of the medical device and enables the creation of a hole  18  in the pelvic bone  9  from the opposite side from acetabulum  8 . According to one embodiment shown in  FIG. 42  the parallel displaced part or section  26  has a telescopic function by means of the parallel displaced part or section  26  being divided in to a first and second part  27   a, b , wherein the second part  27   b  can slide in and out of the first part  27   a.    
       FIG. 43  shows one embodiment in which the operating device  23   b  is be placed in direct connection with the bone contacting organ  22 , in which case the operating device  23   b  also serves as driving member. In this construction a handle portion  24  could be attached to the surgical instrument, facilitating the surgeons handling of said surgical instrument. To improve the reach of the surgical instrument the handle portion  24  could be attached perpendicular to the hole-creating direction  25  of the surgical instrument, it is furthermore conceivable that the handle portion  24  is bent by means of a parallel displaced part or section, a fixed angle, an adjustable angle or a flexible part or section. 
       FIG. 44  shows the surgical instrument according to a second embodiment wherein said surgical instrument comprises a driving member  28   a,b,c  with two angle adjusting members  29   a,b . The angle adjusting members  29   a,b  could be adjustable for varying the angle of said driving member  28   a,b,c  or fixed in an angle suitable for creating a hole in the pelvic bone  9  from the opposite side from acetabulum  8 . In another embodiment (not shown) the part of the driving member  28   c  in connection with the bone contacting organ  22  could be very short enabling the surgical instrument to operate very close to the pelvic bone  9  when creating a hole  18  in said pelvic bone  9 . 
       FIG. 45  shows the surgical instrument according to a third embodiment wherein the driving member  30  is flexible, enabling said driving member  30  to be very precisely adjusted to create a hole  18  in the pelvic bone  9  of the patient. The stiffness of said driving member  30  could range from completely flexible to completely stiff to fit the surroundings of the particular operation. 
       FIG. 46  shows the bone contacting organ according to a first embodiment wherein the bone contacting organ  22   a  is adapted to crate a bone plug  31 . The bone plug  31  could be adapted to be replaced into said hole  18  after the surgical or laparoscopic/arthroscopic steps performed in the hip joint has been concluded. 
       FIG. 47  shows the bone contacting organ according to a second embodiment wherein the bone contacting organ  22   b  is adapted to create small pieces of bone  32  when creating said hole  18  in the pelvic bone  9 . The small pieces of bone could be transported from the area and out of the body using vacuum power or a hydraulic transport system. 
       FIG. 48 a    shows the hip joint in section with the caput femur  5  placed at the very top of collum femur  6 , which is the top part of the femoral bone  7 . The caput femur is in connection with the acetabulum  8 , which is a bowl shaped part of the pelvic bone  9 . According to a first embodiment the hole  18  created in the pelvic bone  9  from the opposite side from acetabulum  8 , is larger than said artificial caput femur surface  45 , enabling the insertion of said artificial caput femur surface  45  in its full functional size. Said insertion of said artificial caput femur surface  45  could be performed as a step of the surgical method, as well as a step of the laparoscopic/arthroscopic method. After the insertion, the artificial caput femur surface  45  is attached to the caput femur  5 , the attaching is performed by means of a mechanical attachment  44  comprising a shaft or screw penetrating the cortex. It is however also conceivable that the mechanical attachment  44  is assisted or replaced by bone cement or adhesive placed between caput femur  5  and the artificial caput femur surface  45 , or in connection with said shaft or screw  44 . Alternative ways of attaching the artificial caput femur surface  45  includes: at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. 
       FIG. 48 b    shows the hip joint in section with the artificial caput femur surface  45  attached to the caput femur  5 . 
     The surgical and laparoscopic/arthroscopic methods described could further comprise the step of reaming the acetabulum  8  or the caput femur  5 . According to a first embodiment the reaming of the acetabulum  8  or the caput femur is performed using an expandable reamer shown in  FIGS. 49-51 . The expandable reamer comprises at least one reaming blade  40  which comprises a reaming surface  41   a,b . Said expandable reamer could be adapted to ream the acetabulum  8 , the caput femur  5  or both. In the embodiment where said expandable reamer is adapted to ream the acetabulum  8  said reaming surface  41   a  is located on the exterior part of the at least one reaming blade  40 , whereas in the embodiment when said expandable reamer is adapted to ream the caput femur  5 , said reaming surface  41   b  is located on the interior part of the at least one reaming blade  40 . According to a second embodiment said expandable reamer is adapted to ream both the acetabulum and the caput femur, in which case the reamer has reaming surfaces  41   a,b  both on the exterior and the interior part of the at least one reaming blade  40 . 
       FIG. 50  shows the expandable reamer, according to any of the embodiments, wherein the reaming blades  40  can be folded towards a center of the semi-sphere that the expandable reamer produces in its expanded state, shown in  FIG. 49 . The folding of the reaming blades  40  enables the expandable reamer to be introduced into a hip joint through a hole smaller than the area possible to ream using said expandable reamer. 
       FIG. 51  shows the interior said of the expandable reamer with the reaming blades  40 . In the embodiment when the expandable reamer is adapted to ream the caput femur, said interior side of the at least one reaming blade  40  comprises a reaming surface  41   b.    
       FIG. 52  shows the expandable reamer according to any of the embodiments when reaming said acetabulum  8  and/or said caput femur  5 . 
     The reamer can be adapted to be operated manually or by means of a rotating, vibrating or oscillating operating device. 
     According the one embodiment the bone contacting organ  22  of the surgical instrument for creating a hole in the pelvic bone can be replace with the expandable reamer shown in  FIGS. 49-51 , in which case the expandable reamer can be powered using the operating device  23   a,b  used in said surgical instrument. 
     After the preparation of the hip joint surfaces the method step of inserting or creating new surfaces is performed. 
       FIG. 53 a    shows how an expandable artificial caput femur surface  45  is being inserted through a hole  18  in the pelvic bone  9 , using a tool for insertion of a medical device  1240 . 
       FIG. 53 b    shows how an expandable artificial caput femur surface  45  goes through the hole  18  in the pelvic bone  9  and travels over caput femur  5 , by means of arms  50  of the artificial caput femur surface making the artificial caput femur surface flexible. 
       FIG. 53 c    shows an expandable artificial caput femur surface  45  is after it has been placed on said caput femur  5 . In this embodiment the artificial caput femur surface arms  50  clasps the caput femur  5 . 
       FIG. 54 a    shows the hip joint in section according to a second embodiment in which the hole  18  in the pelvic bone  9  is smaller than the artificial caput femur surface  45  in its full functional size. According to this embodiment the artificial caput femur surface  45  is introduced into said hip joint through the hole  18  in the pelvic bone  9  form the opposite side from acetabulum  8 . The artificial caput femur surface parts  46  are connected to each other after insertion into said hip joint to form the artificial caput femur surface  45 . 
       FIG. 54 b    shows the hip joint in section when the artificial caput femur surface parts  46  are connected to each other using form fitting  47 , however it is conceivable that the form fitting is assisted or replaced with adhesive or bone cement. After the artificial caput femur surface parts  46  have been introduced and connected in the hip joint, they are mechanically fixated to the caput femur  5 , the mechanical fixation could be done by means of: at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. 
       FIG. 54 c    shows the artificial caput femur surface parts  46  with the parts supplying the form fitting  47  for connecting the parts to each other. 
       FIG. 54 d    shows the hip joint in section wherein a second hole  18   b  in the pelvic bone  9  enables the surgeon to place a camera  34  into the hip joint, preferably used in the laparoscopic/arthroscopic method. 
       FIG. 55 a    shows the femoral bone  7  where multiple positioning shafts  900   a,b,c  are placed in the caput femur  5 . The positioning shafts  900   a,b,c  are adapted to guide, position and center artificial hip joint surface parts  913   a,b  on to the caput femur  5 , or guide, position and center artificial hip joint surface parts  913   a,b  to be placed in the acetabulum. The artificial hip joint surface parts  913   a,b  each have a positioning hole  910   a,b  which are adapted to encircle the positioning shafts  900   a,b,c  placed in the caput femur  5 . The artificial hip joint surface parts  913   a,b  are adapted to be connected to each other after insertion the hip joint using mechanical connecting members  914   a,b , wherein the mechanical connecting members comprises a first part  914   a  placed in a first artificial hip joint surface part  913   b  and adapted to fit in a corresponding second part  914   b , placed in a second artificial hip joint surface part  913   a . The multiple positioning shafts  900   a,b  thereby assists in the connection of multiple artificial hip joint surface parts  913   a,b  to each other. However the mechanical connecting members  914   a,b  could be assisted or replaced by an adhesive. 
       FIG. 55 b    shows the positioning of the artificial hip joint surface parts  913   a,b  from above with the positioning holes  910   a,b  of the artificial hip joint surface parts  913   a,b  encircling the positioning shafts  900   a,b,c  and thereby the positioning shafts  900   a,b,c  guiding, positioning and centering the artificial hip joint surface parts  913   a,b  in the hip joint. 
       FIG. 56  shows a lateral view of a human patient where a surgical instrument  35  adapted to create a hole in the pelvic bone from the abdominal side of the pelvic bone  9  is inserted through an incision in the abdominal wall. The surgical instrument could comprise a flexible part or section  300 , enabling the surgical instrument to be very precisely adjusted to reach the pelvic bone or the hip joint from the abdominal side of the pelvic bone. The stiffness of said flexible part or section  300  could range from completely flexible to completely stiff to fit the surroundings of the particular operation. The surgical instrument  35  could be powered through an operating device which in turn could comprise an electrical, hydraulic, mechanical, pneumatic or magnetic engine and it could be adapted to create a rotating, oscillating, vibrating or repetitive movement. 
     According to another embodiment (not shown) the surgical instrument  35  is powered from an operating device being placed outside of the human body, in the thigh region. The force created in the operating device is then transferred through a force transferring member placed which is placed in the collum femur and femoral bone. This allows the surgeon to supply force to an area of the hip joint and its surroundings through an incision in the thigh. 
       FIG. 57  shows a hip joint in section wherein a surgical instrument  35  adapted to create a hole  18  in the pelvic bone  9  is adapted to create a bone plug  31 . The bone plug  31  could be adapted to be replaced into said hole  18  after the surgical or laparoscopic steps performed in the hip joint has been concluded. 
       FIG. 58  shows a hip joint in section wherein a surgical instrument  604  for removing the caput femur  5  is provided through a hole  18  in the pelvic bone  9 . The surgical instrument is adapted to create a hole in the caput femur  5 , passing down a longitudinal extension of the collum femur  6 . The surgical instrument further comprises a sawing member  605   a,b  adapted to separate the caput femur from the collum femur. In a first state  605   a , the sawing member  605   a  is retracted within the surgical instrument  604 . When the surgical instrument is positioned inside of the collum femur in a desired position the sawing member is folded to a second state  605   b  allowing the sawing member to create a section in the collum femur, separating the caput femur  5  from the collum femur  6 . 
       FIG. 59  shows the hip joint in section when the surgical instrument  604  and the sawing member  605   b  is positioned inside of the collum femur. After the caput femur  5  has been removed, a stabilizing part of the collum femur  6  is retained. The stabilizing part of collum femur  6  could be defined to be the proximal half of said collum femur  6 , the proximal two third of said collum femur, the proximal three quarter of said collum femur, the proximal 90% of said collum femur or the whole collum femur. The proximal part of collum femur being the part of collum femur closest to the torso of the human body. 
       FIGS. 60-64  shows the medical device and the method of placing said medical device according to one embodiment. 
       FIG. 60  shows the removal of the caput femur  5  after the surgical instrument  604  has created a surface of a section  610  substantially perpendicularly to the longitudinal extension of the collum femur  6 . The separated caput femur  5  is then removed through the hole  18  in the pelvic bone  9 . 
       FIG. 61  shows the removal of a piece of bone  609  from the caput femur  5 . The removal of the piece of bone  609  is preferably performed outside of the human body.  FIG. 13  shows the removal of the top part of caput femur  5 ; however it is equally conceivable that the piece of bone is removed from any other side of the caput femur  5 . 
       FIG. 62  shows the medical device  600  according to one embodiment. The medical device comprises a fixating member  608  and an artificial caput femur surface  607 . The artificial caput femur surface  607  is adapted to be in contact with the acetabulum surface  11  or an artificial replacement therefore. The fixating member  608  is adapted to at least partly be stabilized by the cortical bone  601  of a stabilizing part of the collum femur  6 . The stabilizing could be performed from the inside, substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension. The stabilizing could further be performed from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6 , and from the outside, substantially perpendicular to the longitudinal extension of the collum femur  6 , from the inside, substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the outside, substantially perpendicular to the longitudinal extension of the collum femur  6 , or from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6 , and from the outside, substantially perpendicular to the longitudinal extension of the collum femur  6 . The medical device  600  could be adapted to at least partly be directly stabilized by the cortical bone  601  of said stabilizing part of said collum femur  6 , or to be indirectly stabilized by the cortical bone  601  of said stabilizing part of said collum femur  6 . In the embodiments (not shown) when the medical device  600  is indirectly stabilized by the cortical bone  601  of the collum femur  6  it is conceivable that a material is placed between said cortical bone  601  and the fixating member  608  of the medical device  600 . The material could be: bone cement, an at least partly elastic material, glue, adhesive, antibiotic, biocompatible plastic material, biocompatible ceramics and/or a biocompatible metal such as titanium or tantalum. 
     The hole  609  in the piece of bone  606  from the caput femur  5  is preferably the hole created by the surgical instrument  604  in the process of removing the caput femur, however it is conceivable that the hole  609  needs to be altered or adapted for fitting the fixating member  608  which is adapted to be placed inside of the hole  609  in the piece of bone  606  removed from the caput femur  5 . 
       FIG. 63  shows a hip joint in section when the medical device  600 , comprises an artificial caput femur surface  607 , a fixating member  608  and a stabilizing member  606 , being inserted through a hole  18  in the pelvic bone  9 . According to this embodiment the stabilizing member is a piece of bone  606  placed on the outside of the fixating member  608 . The stabilizing member  606  could be fixated to the fixating member  608  using adhesive or any mechanical connection, such as screws, cord, band or pop-rivets. According to this embodiment the medical device is stabilized by the cortical bone  601  of the collum femur  6  on the inside thereof substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6  through the stabilizing member being placed in contact with the surface of a section  610  on the collum femur  6 . The stabilizing member and the fixating member could be fixated to the collum femur  6  by means of an adhesive or bone cement. 
       FIG. 64  shows the hip joint in section when the medical device  600 , according to the first embodiment, has been placed on the collum femur  6  and is stabilized from the inside thereof by the direct or indirect connection with the cortical bone  601  of the collum femur  6 . 
       FIG. 65  shows the caput femur  5  after the proximal part has been removed along the section created by the medical device for creating a hole. The removing of the proximal part of the caput femur  5  creates a surface of a section  102  in the cortical bone of the caput femur  5 . A reamer  40  adapted to create a concave surface  103  in the caput femur  5  is applied to the force transferring member  21  through a connecting section  101 . According to this embodiment the force transferring member  21  is the same as the force transferring member used for the medical device adapted to create a hole in the pelvic bone  9 , however it is equally conceivable that the force transferring member  21  is specifically designed to enable the reaming of the caput femur  5 . The reaming in the caput femur and part of the collum femur  6  is mainly performed in the cancellous bone, however that does not exclude the possibility the some of the reaming needs to be performed in the cortical bone of the caput femur  5  and/or the collum femur  6 . 
       FIG. 66  shows the step of applying an adhesive  106  to the concave surface created by the reamer  40 . The adhesive  106  is applied by an injecting member  104  comprising an injecting nozzle  105 . The adhesive  106  is preferably a biocompatible adhesive such as bone cement. The injecting member  104  is in this embodiment adapted for introduction through a hole  18  in the pelvic bone  9 , through the injecting member  104  being bent. 
       FIG. 67  shows the step of providing a medical device  109  comprising an artificial concave hip joint surface  110 . The artificial concave hip joint surface  110  is fixated to the concave surface  103  created in the caput femur  5  and collum femur  6 . The medical device  109  comprises a fixation support  111  adapted to anchor said artificial concave hip joint surface  110 , to at least one of the caput femur  5  and the collum femur  6 . The medical device  109  is adapted to be introduced to the hip joint through a hole  18  in the pelvic bone  9  using a inserting member  107 . According to this embodiment the inserting member is bent and thereby adapted to operate through a hole  18  in the pelvic bone  9 . The inserting member  107  comprises a connecting member  108  which is adapted to connect to the medical device  109 . According to one embodiment the medical device  109  comprises a self lubricating material such as PTFE, however it is also conceivable that said medical device comprises: titanium, stainless steel, Corian, PE, or other acrylic polymers, in which case the medical device could be adapted to be lubricated after insertion in said hip joint. 
       FIG. 68  shows a medical device comprising an artificial convex hip joint surface  112 . The artificial convex hip joint surface  112  is adapted to be fixated to the pelvic bone  9 , and is adapted to be inserted through a hole  18  in the pelvic bone  9 . The medical device comprises a nut  120 , comprising threads for securely fixating the medical device to the pelvic bone  9 . The medical device further comprises a prosthetic part  118  adapted to occupy the hole  18  created in the pelvic bone  9  after the medical device has been implanted in the patient. The prosthetic part  118  comprises supporting members  119  adapted to be in contact with the pelvic bone  9  and assist in the carrying of the load placed on the medical device from the weight of the human patient in normal use. Normal use is defined as the same as a person would use a natural hip joint. Further the medical device comprises a locking element  116  comprising a surface  117  adapted to be in contact with the artificial convex hip joint surface  112 . The locking element  116  further comprises fixating members  115  which are adapted to assist in the fixation of the locking member  116  to the caput femur  5  or collum femur  6 , which in turns fixates the artificial convex hip joint surface  112 . The artificial convex hip joint surface  112  is fixated to a attachment rod  113  comprising a thread  114  that corresponds to the thread of the nut  120  in connection with the prosthetic part  118 . According to the embodiment shown in  FIG. 68  a part comprising the artificial convex hip joint surface  112 , the attachment rod  113  and the thread  114  is formed by two parts wherein the first part  1241 ′ comprises the first part of the artificial convex hip joint surface  112 , the first part of the attachment rod  113  and the first part of the thread  114 , and the second part  1241 ″ comprises the second part of the artificial convex hip joint surface  112 ′, the second part of the attachment rod  113  and the second part of the thread  114 ′. The first and second parts are adapted to the connected to each other to form a connected part for examples by means of the interconnecting functions as described with reference to  FIGS. 23-30 . 
       FIG. 69  shows the hip joint in section when the artificial convex hip joint surface is fixated in the medical device  109  comprising a concave hip joint surface  110 . The convex hip joint surface  112  is secured in place by the locking element  116  which is fixated to the caput femur using screws  121 . The surface of the locking element  117  and the concave hip joint surface  117  is placed in connection with the convex hip joint surface and could be made of a friction reducing material such as PTFE or a self lubricating powder material. However it is also conceivable that the connecting surfaces are lubricated using an implantable lubrication system adapted to lubricate the medical device after said medical device has been implanted in the human patient. 
       FIG. 70  shows the placing of a prosthetic part  118  adapted to occupy the hole  18  created in the pelvic bone  9 . The prosthetic part  118  comprises supporting members  119  adapted to be in contact with the pelvic bone  9  and assist in the carrying of the load placed on the medical device from the weight of the human patient. According to the embodiment shown in  FIG. 12  the supporting members  119  are located on the abdominal side of the pelvic bone  9 , however it is equally conceivable the supporting members  119  are located on the acetabulum side of the pelvic bone  9 , in which case they are preferably displaceable for allowing insertion of the prosthetic part  118  through the hole  18  in the pelvic bone  9 . Furthermore  FIG. 12  shows the fixation of a nut  120  to the attachment rod  113 . According to the embodiment shown in  FIG. 12  the hole  18  in the pelvic bone  9  is adapted to be larger than the medical device allowing the medical device to be inserted in its full functional size. According to other embodiments the hole  18  is smaller in which case the medical device could comprise of several parts adapted to be connected after insertion in the hip joint, such as shown in  FIG. 68 , or the medical device could be expandable for insertion through a hole smaller than the full functional size of the medical device. The expandable medical device could be enabled through the elements of the medical device comprising elastic material. 
       FIG. 71  shows the hip joint in section when all the elements of the medical device has been fixated in the area of the hip joint or its surroundings. The prosthetic part  113  adapted to occupy the hole  18  in the pelvic bone  9  is here fixated with screws  121 , however these screws  121  could be assisted or replaced by an adhesive which could be applied to the surface S between the prosthetic part and the pelvic bone  9 . 
     In the above embodiments the medical device  600  have been described in the context of a surgical procedure from the abdominal side of the pelvic bone, however it is also conceivable that the medical device is inserted through the a hole in the femoral bone or a hole in the hip joint capsule, and is adapted therefore. A conceptual view of the embodiment where the medical device  600  is inserted through the hip joint capsule as shown with reference to  FIGS. 2-10 , what is commonly described as conventional hip joint surgery. 
     After the step of providing an artificial caput femur surface, the surgical and laparoscopic/arthroscopic methods could further comprise the step of providing an artificial acetabulum surface. 
       FIG. 72  shows an embodiment where an artificial acetabulum surface  65  is pre-mounted onto the artificial caput femur surface  45 . The medical device comprising the artificial caput femur surface  45  further comprises a fixating member  608  and a stabilizing member  612 , adapted to stabilize the medical device  600  from the outside of the collum femur  6  substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6  through the stabilizing member  612  being placed in contact with the surface of a section on the collum femur  6 . According to the embodiment shown in  FIG. 72  the artificial acetabulum surface  65  has a flexible construction with multiple slits  66  enabling the artificial acetabulum surface  65  to pass beyond the maximum diameter of the artificial caput femur surface  45  and thereby clasping the artificial caput femur surface  45 . The artificial acetabulum surface is secured by a band, cord or wire  1223  placed encircling the artificial acetabulum surface  65 . 
       FIG. 73  shows the medical device when the pre-mounted artificial acetabulum surface  65  has been provided and secured by the band, cord or wire  1223  encircling the artificial acetabulum surface  65  beyond the maximum diameter of the artificial caput femur surface  45 . 
       FIG. 74  shows an embodiment where an artificial acetabulum surface  65  is pre-mounted onto the artificial caput femur surface  45 . The medical device comprising the artificial caput femur surface  45  further comprises prosthetic stem for fixation of the medical device in the femoral bone. According to the embodiment shown in  FIG. 74  the artificial acetabulum surface  65  has a flexible construction with multiple slits  66  enabling the artificial acetabulum surface  65  to pass beyond the maximum diameter of the artificial caput femur surface  45  and thereby clasping the artificial caput femur surface  45 . The artificial acetabulum surface is secured by a band, cord or wire  1223  placed encircling the artificial acetabulum surface  65 . 
       FIG. 75  shows the medical device when the pre-mounted artificial acetabulum surface  65  has been provided and secured by the band, cord or wire  1223  encircling the artificial acetabulum surface  65  beyond the maximum diameter of the artificial caput femur surface  45 . 
       FIG. 76  shows the femoral bone, in the step in which the surface of the section  610  in the collum femur  6  is prepared. An adhesive  614  is applied to the surface of the section  610  of the collum femur  6  for fixating the medical device, comprising a pre-mounted artificial acetabulum surface  65  on the artificial caput femur surface, to the collum femur  6  using the fixating member  608  and the stabilizing member  612 . 
       FIG. 77  shows the femoral bone after the step of introducing and fixating the medical device to the collum femur  6  has been preformed. The stabilizing member  612  is adapted to stabilize the medical device  600  from the outside of the collum femur  6  substantially perpendicular to the longitudinal extension of the collum femur  6 , and from the acetabulum side, substantially in line with the longitudinal extension of the collum femur  6  through the stabilizing member being placed in contact with the outside of the collum femur  6  and the surface of the section  610  in the collum femur  6 . The stabilizing member  612  is fixated to the outside of the collum femur  6  and/or to the surface of the section  610  in the collum femur  6  by means of the adhesive  614 . However the adhesive  614  could be replaced or assisted by bone cement or a mechanical fixation element. 
     According to one embodiment the artificial acetabulum surface  65  is provided through a hole  18  in the pelvic bone  9  from the opposite side from acetabulum  8 . 
       FIG. 78  shows an artificial acetabulum surface  65  in its full functional size as it is being inserted through a hole  18  in the pelvic bone  9 . 
       FIG. 79  shows an artificial acetabulum surface  65  according to a second embodiment in which the artificial acetabulum surface  65  comprises at least one slit  66  enabling the artificial acetabulum surface  65  to vary in size for insertion through a hole  18  in the pelvic bone  9  smaller than the full functional size of the artificial caput femur surface  45 . The slits are placed between one or more artificial acetabulum surface arms  67  which are flexible by means of the material or by means of a joint affecting said artificial acetabulum surface arms  67 . 
       FIG. 80   a,b,c  shows an artificial acetabulum surface  65  according to a second embodiment in which the artificial acetabulum surface  65  comprises multiple artificial acetabulum surface parts  68 . Said multiple artificial acetabulum surface parts  68  are adapted to be connected to an interconnecting artificial acetabulum surface part  69  after insertion into a hip joint. The interconnecting artificial caput femur surface part  69  comprises self locking connecting members  70   a , shown in  FIG. 80 b   , that fits with corresponding self locking members  70   b  of the artificial acetabulum surface parts  68 . The artificial acetabulum surface parts  68  create an artificial acetabulum surface  65  when connected to each other, shown in  FIG. 80 c   . The self locking members  70   a,b  can be assisted or replaced with at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. 
       FIG. 81   a,b,c  shows an artificial acetabulum surface  65  according to a third embodiment in which the artificial acetabulum surface  65  comprises multiple ring-shaped artificial acetabulum surface parts  71 . Said multiple ring-shaped artificial acetabulum surface parts  71  are adapted to be connected to each other to form an artificial acetabulum surface  65  after insertion in a hip joint. According to one embodiment said artificial acetabulum surface parts  71  are adapted to be connected to each other using mechanical connecting members  72   a,b .  FIG. 81 c    shows how an individual ring-shaped artificial acetabulum surface part  71  can be connected to itself using the mechanical connecting member  72   a  to form a continuous ring shape. Further  81   c  shows how an individual ring-shaped artificial acetabulum surface part  71  connects to other ring-shaped artificial acetabulum surface parts  71  using the mechanical connecting member  72   b  to form an artificial acetabulum surface  65 . 
       FIG. 82   a,b,c,d  shows an artificial acetabulum surface  65  according to a fourth embodiment in which the artificial acetabulum surface  65  comprises a first  73   a  and a second  73   b  section, shown in  FIG. 82 b   . The first and second sections are displaceable in relation to each other. According to a first embodiment said first section  73   a  can be rotated in relation to said second section  73   b  so that said second section  73   b  travels underneath said first section  73   a  to create a displaced artificial acetabulum surface  74 , as shown in  FIG. 38 c   , which is possible to insert into a hip joint of a human patient through a hole being oval, or at least having an area smaller than the cross sectional area of the artificial acetabulum surface  65  when in its full functional size 65. According to this embodiment the two sections  73   a,b  are connected to each other when the artificial acetabulum surface is returned to its full functional size using a mechanical form fitting  75 , as shown in  FIG. 82 d   . However it is also conceivable that said connection is assisted or replaced with at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. 
       FIG. 83 a    shows an artificial acetabulum surface  65  according to a fifth embodiment in which the artificial acetabulum surface  65  comprises four slits  66 . The artificial acetabulum surface  65  is flexible in its construction allowing the four artificial acetabulum arms  67  to be folded towards the center axis of the artificial acetabulum surface  65  thus allowing the artificial acetabulum surface to be inserted into a hip joint through a hole smaller than the full functional size of the artificial acetabulum surface  65 . 
       FIG. 83 b    shows the artificial acetabulum surface  65  according to the fifth embodiment in its folded state. The artificial acetabulum surfaces  65  of any of the embodiments could be adapted to pass beyond the maximum diameter of the caput femur  5  and thereby fixate the artificial acetabulum surface  65  to the caput femur, or an artificial replacement therefore, by clasping the caput femur  5 . 
       FIG. 84 a    shows a surgical instrument adapted to insert a prosthesis, prosthetic parts or parts needed to create or provide a hip joint surface, according to a first embodiment. The surgical instrument comprises a gripping portion  76  and a handling portion  77 . According to the embodiments shown in  FIG. 84   a,b,c  the instrument further comprises a rotation element  78  that enables the gripping part  76  to rotate in relation to the handling part  77 , however it is equally conceivable that the surgical instrument lacks this rotation element  78 . 
       FIG. 84 b    shows the surgical instrument adapted to insert a prosthesis, prosthetic parts or parts needed to create or provide a hip joint surface, according to a second embodiment. According to this embodiment the surgical instrument further comprises a parallel displaced section  79 , which increases the reach of the instrument and facilitates the reaching of the hip joint through a hole in the pelvic bone from the opposite side from acetabulum. 
       FIG. 84 c    shows the surgical instrument adapted to insert a prosthesis, prosthetic parts or parts needed to create or provide a hip joint surface, according to a third embodiment. According to this embodiment the surgical instrument further comprises two angle adjusting members  84   a,b . The angle adjusting members could be adjustable for varying the angle of said gripping part  76  in relation to the handling portion  77 , or fixed in an angle suitable for creating operating in a hip joint through a hole in the pelvic bone from the opposite side from acetabulum  8 . 
       FIG. 85  shows the hip joint in section after the artificial caput femur surface  45 , and the artificial acetabulum surface  65  have been provided through a hole in the pelvic bone. 
       FIG. 86  shows an artificial bowl shaped acetabulum cup  65  placed in the pelvic bone  9 . The artificial bowl shaped acetabulum cup  65  comprises releasing members  801  adapted, in a first state, to hold the caput femur  5  which is a ball shaped piece attached to the collum femur  6  in position in the hip joint to the artificial bowl shaped acetabulum cup  65  placed in the pelvic bone  9 . In a second state the releasing member  801  is adapted to release the caput femur  5 , or an artificial replacement therefore, from the artificial bowl shaped acetabulum cup  65  placed in the pelvic bone  9 . The releasing member  801  is adapted to change from the first state to the second state when a pre-determined strain is placed on the releasing member  801 . The strain is preferably caused by an abnormal movement of the hip joint, e.g. as the result of the patient falling. According to the embodiment shown in  FIG. 9  the releasing member  801  comprises an elastic portion comprising elastic material, in the embodiment shown being the entire releasing member  801 . The releasing member is adapted to non-invasively be able to change from the first state to the second state and from the second state to the first state, when a pre-determined strain is placed on the releasing member  801 . 
       FIG. 87  shows the hip joint in section when the releasing member  801  is in its second state, wherein the releasing member  801  is adapted to release the caput femur  5 , or an artificial replacement therefore, from the artificial bowl shaped acetabulum cup  65  placed in the pelvic bone  9 . The releasing member  801  has changed from the first state to the second state because of a pre-determined strain has been placed on the releasing members  801 . 
       FIG. 88  shows the medical device according to an embodiment where the artificial bowl shaped acetabulum surface  65  comprises releasing members  801  comprising holding members  802   a,b  adapted to slide against the caput femur  5 , or an artificial replacement therefore. The holding members are adapted to, in a first state, hold the caput femur  5 , or an artificial replacement therefore, which is a ball shaped part attached to the collum femur  6  in position in the hip joint to the artificial bowl shaped acetabulum cup  65  placed in the pelvic bone  9 . In a second state the releasing member  801  is adapted to release the caput femur  5 , or an artificial replacement therefore, from the artificial bowl shaped acetabulum cup  65  placed in the pelvic bone  9 . The holding members  802   a,b  are spring loaded through a spring  803   a,b  being placed between a calibration member, being a calibration screw  804   a,b , and the holding members  802   a,b . The force exerted on the holding members  802   a,b  from the spring  803   a,b  is adapted to hold the caput femur  5 , or an artificial replacement therefore, in the artificial acetabulum  65  in normal, functional hip joint movements, but release the caput femur  5 , or an artificial replacement therefore, from the artificial acetabulum  65  when a pre-determined strain is placed on the releasing member preferably being caused by an abnormal movement of the hip joint, e.g. as the result of the patient falling. The calibration screws  804   a,b  enables the pre-determination of the strain which will cause the holding members  802   a,b  to change from being in a first state to being in a second state. 
       FIG. 89  shows the releasing members in their second state, when a pre-determined strain has been exceeded, preferably being caused by an abnormal movement of the hip joint, e.g. as the result of the patient falling. The holding members  802   a,b  are retracted into sleeves  806  of the artificial acetabulum surface  65 , thereby compressing the springs  803   a,b . The retraction of the holding members  802   a,b  causes the caput femur  5 , or an artificial replacement therefore, to be dislocated/luxated from its position in the artificial acetabulum surface  65 , which, when large strain is placed on the hip joint and femoral bone  7 , reduces the risk of the patient fracturing the femoral bone  7  or the pelvic bone  9 . The holding members  802   a,b  are adapted to non-invasively be able to change from the first state to the second state and from the second state to the first state, when a pre-determined strain is placed on the holding members  802   a,b.    
       FIG. 90  shows the artificial acetabulum  65  in section with the holding members  802 , placed in sleeves  806  evenly distributed along the cross-section of the artificial acetabulum  65 , holding the caput femur  5 , or an artificial replacement therefore, in position in the artificial acetabulum  65 . 
       FIG. 91  shows an alternative embodiment of the principle shown in  FIGS. 88-90 , wherein the holding members  802   a,b , comprises ball shaped members  805   a,b  in contact with the caput femur  5 , or an artificial replacement therefore, ant being adapted to roll against the caput femur  5 , or an artificial replacement therefore, holding the caput femur  5 , or an artificial replacement therefore, in place in the artificial acetabulum  65  by the holding members  802   a,b  exerting force on the caput femur  5 , or an artificial replacement therefore, through the contact with the springs  803   a,b  supported by the calibration screws  804   a,b.    
       FIG. 92  shows the releasing members in their second state, when a pre-determined strain has been exceeded, preferably being caused by an abnormal movement of the hip joint, e.g. as the result of the patient falling. The holding members  802   a,b , comprising the ball shaped members  805   a,b , are retracted into sleeves  806  of the artificial acetabulum surface  65 , thereby compressing the springs  803   a,b . The retraction of the holding members  802   a,b  causes the caput femur  5 , or an artificial replacement therefore, to be dislocated/luxated from its position in the artificial acetabulum surface  65 , which, when large strain is placed on the hip joint and femoral bone  7 , reduces the risk of the patient fracturing the femoral bone  7  or the pelvic bone  9 . The holding members  802   a,b  are adapted to non-invasively be able to change from the first state to the second state and from the second state to the first state, when a pre-determined strain is placed on the holding members  802   a,b , which enables the caput femur  5 , or an artificial replacement therefore, to be replaced in the artificial acetabulum  65  without a surgical procedure. 
       FIG. 93  shows the medical device in an embodiment wherein the releasing members  801  comprises a rupture device  807 ,  808 ,  809  adapted to fail at a pre-determined strain. According to this embodiment the rupture device is a rupture pin  807 ,  808 ,  809  comprising a base part  809   a,b  fixated to the artificial acetabulum  65  and a rupture part  807   a,b  attached to the base part  809   a,b  through a weakened section  808   a,b , in which section the rupture part  807   a,b  is detached from the base part  809   a,b  when a predetermined strain is placed on the rupture device in contact with the caput femur  5 , or an artificial replacement therefore. 
       FIG. 94  shows the medical device according to the embodiment of  FIG. 93  when the rupture device has failed due to a pre-determined strain on the rupture device being exceeded. According to one embodiment, (not shown) the rupture parts  807   a,b  are secured to the base part through a security wire keeping rupture parts  807   a,b  in proximity to the base part  809   a,b  even after the failure of the rupture device. 
       FIG. 95 a    shows the medical device according to an embodiment where the artificial acetabulum  65  comprises a circular sleeve  806 , in which an elastic or rupture band  810  is provided. The elastic or rupture band  810  is adapted to at least partly encircle the ball shaped caput femur  5 , or artificial replacement therefore. When a pre-determined strain is placed on the elastic or rupture band  810  the circular opening encircling the caput femur  5 , or an artificial replacement therefore, is expanded and the caput femur  5 , or an artificial replacement therefore, is released from the artificial acetabulum  65 , to which it is held by means of the elastic band  610 . In embodiments where the medical device comprises a rupture band  810  holding the caput femur  5 , or an artificial replacement therefore, in the artificial acetabulum  65 , a weakened portion  811  of the band  810  fails and thus the circular opening encircling the caput femur  5 , or an artificial replacement therefore, is expanded and the caput femur  5 , or an artificial replacement therefore, is released from the artificial acetabulum  65 . In the embodiments where the band  810  is an elastic band  810  it is conceivable that the band  810  comprises an elastic part or section, or that the entire band  810  is made of an elastic material. 
       FIG. 95   b  shows the medical device in section when the elastic or rupturing band  810 , holding the caput femur  5 , or an artificial replacement therefore, is placed in a circular sleeve  806  in the artificial acetabulum  65 . An opening or weakened portion  811  is provided perpendicular to the circumference of the band  810 . 
       FIG. 96 a    shows the medical device in a second state where the caput femur  5 , or an artificial replacement therefore, is released from the connection with the acetabulum, after a pre-determined stain has been placed on the elastic or rupture band  810 . As shown in  FIG. 96 b    the gap or weakened part has been expanded, thereby allowing the caput femur, or an artificial replacement therefore,  5  to pass through the opening defined by the elastic or rupture band  810 . The medical device could be adapted to non-invasively be able to change from the first state to the second state and from the second state to the first state, when a pre-determined strain is placed on the band  810 , which enables the caput femur  5 , or an artificial replacement therefore, to be replaced in the artificial acetabulum  65  without a surgical procedure. 
       FIG. 97  shows the medical device according to an embodiment where the releasing member  801  comprises an elastic wing of the artificial acetabulum  65 , which is assisted by an elastic or rupture band  810  encircling the medical device by enclosing the caput femur  5 , or an artificial replacement therefore, in the artificial acetabulum  65  passing beyond the point of the caput femur  5 , or an artificial replacement therefore, having a largest cross-sectional distance. The elastic or rupture band  810  is held in place to the artificial acetabulum  65  by means of the band  810  being placed in a groove along the circumference of the artificial acetabulum  65 . However, said groove could be assisted or replaced by an adhesive or a mechanical fixation element. 
       FIG. 98  shows the medical device when in its second state, in which the releasing member  801  releases the caput femur  5 , or an artificial replacement therefore, from the artificial acetabulum  65 . In embodiments when the band  810  is an elastic band  810  it is expanded, thereby enlarging the hole through which the caput femur  5 , or an artificial replacement therefore, can pass. In embodiment where the band  810  is a rupture band, the band  810  has failed and thereby the caput femur  5 , or an artificial replacement therefore, is held in place solely by the releasing member  801  which is adapted to release the caput femur  5 , or an artificial replacement therefore, at a pre-defined strain. The medical device could be adapted to non-invasively be able to change from the first state to the second state and from the second state to the first state, when a pre-determined strain is placed on the band  810  and/or the releasing member  801 , which enables the caput femur  5 , or an artificial replacement therefore, to be replaced in the artificial acetabulum  65  without a surgical procedure. 
       FIG. 99  shows a prosthetic part  818  according to an embodiment where the prosthetic part  818  is fixated to the femoral bone  7  and comprises a caput femur  812  comprising a cavity  816  adapted to enable the hip joint to perform functional hip joint movements while in a first state held to the artificial acetabulum using an elastic bend  817  fixated to a fixation portion  814  of the artificial caput femur  812 , and a fixating portion  815  of the artificial acetabulum  65 , and a releasing member  801  according to the embodiment shown in  FIGS. 9 and 10 . The combination of the releasing member  801  and the elastic band  817  is adapted to, in a first state hold the prosthetic part  818  to the artificial acetabulum  65 , and in a second state release the prosthetic part  818  from the artificial acetabulum  65 . According to another embodiment (not shown) the prosthetic part is held to the artificial acetabulum  65  solely using the elastic band  817 , of course also supported by the remainder of the hip joint capsule and the affected muscles. 
       FIG. 100  shows the embodiment of the medical device according to  FIG. 99 , in a second state in which the elastic band  817  is stretched such that the prosthetic part  818  is released from the artificial acetabulum artificial acetabulum  65 . The elastic band  817  could be fixated to a fixation portion  814  of the artificial caput femur  812 , and/or a fixating portion  815  of the artificial acetabulum  65  using: at least one screw, at least one pin, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. The failing of the rupture band  813  is preferably caused by an abnormal movement of the hip joint, e.g. as the result of the patient falling. Preferably the elastic band  817  comprises an elastic part or section, which could be the entire elastic band  818 , made from an elastic material, such as an elastic polymer material such as: a copolymer material such as polystyrene, poly(ethylene-butylene) or polystyrene. It is also conceivable that the material is a polyurethane elastomeric material, polyamide elastomeric materials and polyester elastomeric materials elastic copolymers of ethylene and at least one vinyl monomer such as, for example, vinyl acetates, unsaturated aliphatic monocarboxylic acids, and esters of such monocarboxylic acids. The elastic band  813  could comprise a barrier coating, which cannot be penetrated by body cells. Preferably, the barrier coating comprises a Parylene coating, or a biocompatible metal coating, such as gold, silver or titanium. According to other embodiments the elastic band comprises a spring type member, a combination of metal and plastic materials, a combination of metal and carbon based material or a combination of carbon and plastic based material. 
       FIG. 101  shows the hip joint in section in an embodiment where the medical device comprises a prosthetic part  819  adapted to be fixated to the femoral bone  7 . The prosthetic part comprises an artificial caput femur which is adapted to comprise elastic elements  820  which act as a releasing member holding the artificial caput femur inside of the artificial acetabulum  65  fixated to the pelvic bone. The elastic elements  820  of the artificial caput femur, is preferably made of an elastic material, which for example could be an elastomeric polymer material or an elastic metal material. It is conceivable that the elastic material comprises an outer layer in connection with the artificial acetabulum  65  which is adapted to resist the wear from the contact with the artificial acetabulum surface, which could be a ceramic material. The elastic element is adapted to compress when a pre-determined strain is placed on the hip joint and thereby on the elastic elements  820 . When the elastic elements  820  are compressed the artificial caput femur is released from the artificial acetabulum  65 . 
       FIG. 102  shows the medical device according to the embodiment shown in  FIG. 101 , in a second state, in which the elastic element  820  has been compressed, following a pre-determined strain being placed on the medical device. The medical device is thereby placed in a second state, in which the artificial caput femur is released from the artificial acetabulum  65 , wherein it has been held. 
       FIG. 103  shows an embodiment of the medical device in which the elastic elements  820  are further assisted by a spring  821  in connection with two elastic elements  820 , the spring  821  is compressed alongside the elastic members  820 , when a pre-determined strain is placed on the prosthetic part  819  comprising the artificial caput femur. 
       FIG. 104  shows an artificial expandable acetabulum surface  65  being fixated in the pelvic bone  9 . The artificial acetabulum surface  65  is adapted to travel beyond the maximum diameter of the caput femur  5  and thereby clasping the caput femur  5 . An artificial caput femur surface  45  has been provided on the caput femur  5 , the artificial caput femur passing beyond the maximum diameter of the caput femur  5  and thereby clasping the caput femur  5 . The construction with surfaces passing beyond the maximum diameter of the caput femur  5  enables a stable fixation of the hip joint surfaces and reduces the risk of luxation. 
     A different approach to the step of providing an artificial hip joint surface will now be described. This approach comprises the steps of casting an artificial hip joint surface inside of the hip joint. These steps can be performed by means of a mould; such mould may also be using human parts such as caput femur and/or acetabulum or any of the artificial hip joint surfaces. 
       FIG. 105  shows the step of placing a mould  81  inside of the hip joint of a human patient through a hole  18  in the pelvic bone  9 . The step of placing said mould  81  can be performed in the surgical, or in the laparoscopic/arthroscopic method. 
       FIG. 106   a,b,c,d  shows an alternative approach to placing said mould  81  in the hip joint of a human patient. Said alternative approach comprises the steps of creating a hole  82  in the femoral bone  7  following a length axis of the collum femur  6 , said hole starting from the lateral side of the thigh, penetrating the cortex of the femoral bone  7  and eventually reaching the cortex of the caput femur  5  from the inside thereof, penetrating said cortex and entering into the hip joint. After the creation of the hole  82  in the femoral bone  7  the mould  81  is inserted into the hip joint through the hole  82  using a surgical instrument  83  adapted therefore, shown in  FIG. 106   b.    
       FIG. 106 c    shows the mould  82  when being inserted into the hip joint using the surgical instrument  83  adapted therefore. 
       FIG. 106 d    shows the mould  82  after insertion into the hip joint, the surgical instrument used to place said mould  82  in the hip joint is retracted after the insertion is completed. 
     It is also conceivable that the hip joint surface is provided by casting the hip joint surface inside of the hip joint without the use of a mould. 
       FIG. 107  shows the hip joint in section wherein a first sealing member  84  is inserted through a hole  18  in the pelvic bone  9  using an instrument adapted therefore  85 . The step of placing said first sealing member  84  can be performed in the surgical, or in the laparoscopic/arthroscopic method. 
       FIG. 108  shows the hip joint in section wherein a second sealing member  86  is inserted through the surgical or laparoscopic/arthroscopic method. The first  84  and second  86  sealing members creates a sealed space  87  between the acetabulum  8  and the caput femur  5  or one or two artificial replacements therefore, adapted to be used as a mould for providing an artificial acetabulum  65  and/or a caput femur surface  45 . 
       FIG. 109   a,b,c  shows an alternative approach to placing said first sealing member  84  in the hip joint of a human patient. Said alternative approach comprises the steps of creating a hole  82  in the femoral bone  7  following a length axis of the collum femur  6 , as shown in  FIG. 46 a   , said hole starting from the lateral side of the thigh, penetrating the cortex of the femoral bone  7  and eventually reaching the cortex of the caput femur  5  from the inside thereof, penetrating said cortex and entering into the hip joint. After the creation of the hole  82  in the femoral bone  7  the first sealing member  84  is inserted into the hip joint through the hole  82  using a surgical instrument  88  adapted therefore, as shown in  FIG. 109   c.    
       FIG. 110   a,b,c  shows the surgical instrument adapted to insert a mould  81  and/or a first and second sealing member  84 , 86  into the hip joint of a human patient through a hole  18  in the pelvic bone  9  or a hole  82  in the femoral bone  9 . 
       FIG. 110 b    shows a section of the surgical instrument  83 , 85 , 88  comprising a tube like element for housing of the mould  81  and/or said first and second sealing members  84 , 86 . A piston  89  used to transport said mould  81  and/or first and second sealing members  84 , 86  into the hip joint of a human patient is also shown. 
       FIG. 110 c    shows a the surgical instrument  83 , 85 , 88  adapted to insert a mould  81  and/or a first and second sealing member  84 , 86  into the hip joint of a human patient, the second embodiment further comprises a flexible or bent part  91  improving the reach of the surgical instrument. 
     After the steps of providing a mould  81  or a sealed space  87 , fluid is injected into said mould  81  or into said sealed space  87  through the hole  18  in the pelvic bone  9  or the hole  82  in the femoral bone  7 . 
       FIG. 111  shows the hip joint in section wherein an injecting member  92  injects a fluid  93  into a sealed area  87  in the hip joint through a hole  18  in the pelvic bone  9  from the opposite side from acetabulum  8 . Said sealed area  87 , is sealed by a first  84  and second  86  sealing member. The injecting member  92  comprises a piston  94  that pushes said fluid  93  into the sealed area  87 . 
       FIG. 112  shows the hip joint in section wherein an injecting member  92  injects a fluid  93  into a mould  81  in the hip joint through a hole  82  in the femoral bone  7 . The injecting member  92  comprises a piston  94  that pushes said fluid  93  into the mould  81 . 
       FIG. 113  shows the hip joint in section wherein an injecting member  92  injects a fluid  93  into a sealed area  87  in the hip joint through a hole  82  in the femoral bone  7 . The sealed area  87  is sealed by at least a first  84  sealing member. The injecting member  92  comprises a piston  94  that pushes said fluid  93  into the sealed area  87 . 
       FIG. 114  shows the sealed area  87 , sealed by the first  84  and second  86  sealing member together with the caput femur  5  and the pelvic bone  9 . A fluid adapted to harden  93  has been injected into said sealed area, and after the hardening of said fluid it provides at least one hip joint surface. 
       FIG. 115  shows a lateral section of the human body wherein an injecting member  92  injects a fluid into a mould  81  in the hip joint through a hole  18  in the pelvic bone  9  from the opposite side from acetabulum  8 . 
     After the injecting member  92  has injected a fluid  93  into a mould  81  or a sealed are  87  it is being retracted from the area. 
     The mould  81  and the first and second sealing members  84 ,  86  according to any of the embodiments can further be adapted to be resorbable by the human body or to melt after they have served their purpose. 
     After at least one hip joint surface has been provided through a hole  18  in the pelvic bone  9 , in accordance with any of the embodiment above, said hole  18  needs to be closed. 
     All embodiments described above related to a mould or molding or injecting, injecting also by human tissue created space or any instruments related to any method above may also be used inserting any part through the hip joint capsule. Both the first and second sealing member may be inserted that way. 
       FIG. 116  shows the hip joint of a human patient in section wherein a bone plug  31  is placed in the hole  18  in the pelvic bone  9  to close said hole  18 . According to a first embodiment the artificial acetabulum surface  65  comprises supporting members  94  which carries the load placed on the acetabulum  8  from weight of the human patient through the contact with the caput femur  5 . Said supporting members can be adapted to be displaceable  97  supporting members. The bone plug  31  can be attached to the artificial acetabulum surface  11  and/or the pelvic bone  9  by means of bone cement, adhesive, at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. 
       FIG. 117  shows the hip joint of a human patient in section wherein the bone plug  31  placed in the hole  18  in the pelvic bone  9  is further supported by supporting means  96  placed between the bone plug  31  and the pelvic bone  9  on the opposite side from acetabulum  8  using at lest one of: bone cement, adhesive, at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. 
       FIG. 118  shows a bone plug  31  or a prosthetic part  98  comprising several displaceable supporting members adapted to carry the load placed on the acetabulum  8  from weight of the human patient through the contact with the caput femur  5 . The displaceable parts  97  are displaced into a corresponding part in or at the edge of the hole  18  in the pelvic bone  9 . 
     According to a second embodiment the closing of the hole  18  in the pelvic bone is done by means of a prosthetic part  98 . 
       FIG. 119 a    shows the prosthetic part  98  being inserted into a hole  18  in the pelvic bone  9  from the opposite side from acetabulum  8 . According to one embodiment the prosthetic part  98  comprises supporting members  99  adapted to correspond with sections  100  of the hole  18  in the pelvic bone  9 . After the prosthetic part  98  has been inserted into said hole  18  in the pelvic bone  9  it is rotated so that the supporting members  99  comes in contact with the pelvic bone  9  and can carry the load placed on the acetabulum  8  from weight of the human patient through the contact with the caput femur  5 . 
     Said prosthetic part  98  could also be adapted to serve as artificial acetabulum surface  65  according to any of the above mentioned embodiments. 
       FIG. 119 b    shows the prosthetic part  98  when rotated to carry the load placed on the acetabulum  8  from weight of the human patient through the contact with the caput femur  5 . 
     This supporting means could be constructed in many different ways and this should be seen as examples. 
       FIG. 119 c    shows the hip joint of a human patient in section wherein the prosthetic part  98  closes the hole  18  in the pelvic bone  9  and carries the load placed on the acetabulum  8  from weight of the human patient through the contact with the caput femur  5  by means of the supporting members  99 . The prosthetic part  98  can further be fixated to the pelvic bone  9  by means of bone cement, adhesive, at least one screw, at least one pin, at least one portion of at least one of the parts adapted to be introduced into the other part, the parts being adapted to be sliding into the other part, form fitting, welding, adhesive, pin, wire, a ball mounted into a bowl being portions of said parts, a male portion of one part mounted into a female portion of the other part, a key introduced into a lock being portions of said parts, band, or other mechanical connecting members. 
       FIG. 120  shows the hip joint of a human patient in section wherein bone plug  31  or prosthetic part  98  is attached to the pelvic bone  9  by means of screws  101  placed from the opposite side from acetabulum  8 . The screws  101  are possible to place in different angles depending on reach or need for support. This construction may be performed in many different ways for 
       FIG. 121  is a schematic figure of the pelvic bone in section. The pelvic bone comprises an inner cortex  201   a  placed on the abdominal side of the pelvic bone AB, and an outer cortex  201   b  placed on the acetabulum side of the pelvic bone AC. The inner and outer cortex  201   a,b  comprises cortical bone, which is a more dense sclerotic bone. The pelvic bone further comprises cancellous bone  202 , placed in the bone marrow between said inner cortex  201   a  and said outer cortex  201   b . The supporting members of the medical device according to any of the embodiments above can be adapted to be in contact with the outside of the inner cortex  201   a  as supporting member  203 , or be placed inside of the inner cortex  201   a  as supporting member  204 , which enables the supporting member to carry loads in the direction of the abdomen AB as well as in the direction of the acetabulum AC. It is furthermore conceivable that the supporting member is placed in the middle of the inner cortex  201   a  and the outer cortex  201   b , in the cancellous bone, as supporting member  205 , in which case the supporting member could be in contact with the inner cortex  201   a , on the inside thereof, and the outer cortex  201   b , on the inside thereof, which enables the supporting member to carry loads in the direction of the abdomen AB as well as in the direction of the acetabulum AC. Further, the supporting members can be adapted to be in contact with the outside of the outer cortex  201   b  as supporting member  207 , or be placed inside of the outer cortex  201   b  as supporting member  206 , which enables the supporting member to carry loads in the direction of the abdomen AB as well as in the direction of the acetabulum AC. 
       FIG. 122 a    shows the hip joint of a human patient in section wherein bone plug  31  or prosthetic part  98  is attached to the pelvic bone  9  by means of a plate  102  at least partly covering said bone plug  31  or prosthetic part  98 . According to a first embodiment the plate  102  is attached to the pelvic bone  9  by means of screws  103  placed from the opposite side from acetabulum  8 . However it is also conceivable that said screws  103  can be replaced or assisted by bone cement, adhesive, form fitting, welding, sprints, band or some other mechanical connecting member. 
       FIG. 122 b    shows the hip joint of a human patient in section wherein two bone plugs  31  or prosthetic parts  98  are attached to the pelvic bone  9  by means of a plate  102  at least partly covering said bone plugs  31  or prosthetic parts  98 . According to a first embodiment the plate  102  is attached to the pelvic bone  9  by means of screws  103  placed from the opposite side from acetabulum  8 . However it is also conceivable that said screws  103  can be replaced or assisted by bone cement, adhesive, form fitting, welding, sprints, band or some other mechanical connecting member.  FIG. 122 b    also shows the provided artificial acetabulum surface  65 . 
       FIG. 122 c    shows the hip joint of a human patient in section wherein two holes  18  in the pelvic bone has been covered by means of a fluid injected into said holes  18 , through sealing members  104 , said fluid  93  being adapted to harden. Furthermore a plate  102  has been provided at least partly covering said holes  18 . According to a first embodiment the plate  102  is attached to the pelvic bone  9  by means of screws  103  placed from the opposite side from acetabulum  8 . However it is also conceivable that said screws  103  can be replaced or assisted by bone cement, adhesive, form fitting, welding, sprints, band or some other mechanical connecting member.  FIG. 122 c    also shows the provided artificial acetabulum surface  65 , and the provided artificial caput femur surface  45 . 
       FIG. 123 a    shows an injecting member  105  for injecting a fluid adapted to harden  93 , preferably bone cement or adhesive to be used as support in the closing of the hole  18  in the pelvic bone  9 . The injecting member  105  comprises a piston  94  that pushes said fluid  93  the area where it is wanted. 
       FIG. 123 b    shows the injecting member  105  as it is inserted through the skin  106  of a human patient in the surgical or laparoscopic/arthroscopic method, and is further placed in connection with the hip joint through the hole  18  in the pelvic bone  9 . The injecting member  105  is adapted to inject a fluid  93  adapted to harden. 
       FIG. 124  shows the injecting member  105  according to any of the embodiments above, adapted to inject fluid  93  into a mould  81 , a sealed area  87  or a connecting area between the pelvic bone  9  and a prosthetic part, the pelvic bone  9  and a bone plug  31  or the caput femur  5  and a prosthetic part. Said injecting member  105  comprises a container  107  adapted to hold a fluid for injection. According to a first embodiment said container  107  comprises two compartments  108   a,b  adapted to hold two different fluids, said fluids being adapted to harden when mixed. In the embodiment when the container  107  is adapted to hold two fluids, it is conceivable that the injecting member  105  further comprises a mixing member  109  wherein said two fluids are being mixed before injection. According to a second embodiment (not shown) a container is adapted to keep said fluid sterile. According to a third embodiment (not shown) a container is adapted to keep said fluid cold and according to a fourth embodiment (not shown) a container is adapted to keep said fluid in a dark environment. Furthermore a combination of the above mentioned embodiments is conceivable. 
     After the step of closing the hole in the pelvic bone of the human patient is concluded all instruments are retracted and the final step of the surgical or laparoscopic/arthroscopic method is performed. The final step comprises suturing or stapling the affected tissue and finally suturing or stapling the skin of the human patient. 
       FIG. 125 a    shows the step of suturing  110  or stapling  111  the skin  106  of the human patient in the surgical method, whereas  FIG. 125 b    shows the step of suturing  110  or stapling  111  the skin  106  of the human patient in the laparoscopic/arthroscopic method. The laparoscopic/arthroscopic method may not need any suturing. 
       FIG. 126  shows the human patient in a frontal view when an implantable lubrication system  120  has been implanted. The implantable lubrication system  120  is adapted to inject a lubricating fluid continuously, intermittently or when needed into said hip joint. According to the embodiment shown in  FIG. 126  the implantable lubricating system comprises two interconnected units  121 ,  122 . The two interconnected units are placed in the abdominal region of the human patient and is in connection with the hip joint through a fluid transferring member  129 . 
       FIG. 127  shows the implantable lubricating system  120  in further detail, According to the embodiment shown the implantable lubricating system comprises a first unit  121  comprising a pumping member  123  adapted to pump the lubricating fluid from a reservoir  127  to an area of the hip joint. The first unit  121  furthermore comprises an injection port  125  for filling the reservoir  127  from outside of the human body without having to perform a surgical procedure. The injection port  125  comprises a self-sealing membrane which is penetratable with a needle attached to a syringe. The first unit  121  further comprises a receiver of wireless energy  124  preferably comprising a coil. Said receiver of wireless energy is used to charge a battery  126 . According to this embodiment the implantable lubrication system  120  further comprises a second unit  122  which in turn comprises a battery  126  and a fluid reservoir  127 . The lubricating fluid  128  is pumped from the reservoir, through the first unit  121  with the pumping device, through the fluid transferring member  129  and into the area of the hip joint where it helps lubricating the hip joint surfaces. The lubricating fluid is preferably a biocompatible lubricating fluid such as hyaluronic acid. 
       FIG. 128  shows the implantable lubricating system according to an embodiment wherein the implantable lubricating system is a circulating lubricating system comprising one inlet  130  into the joint to be lubricated and one outlet  131 . Preferably this system is a system for continuous lubrication where the pumping member  123  continuously circulates the lubricating fluid  128  inside of the hip joint. 
       FIG. 129  shows an implantable lubricating system for circulating lubrication wherein the lubricating system further comprises a filtering member  132  for filtering the lubricating fluid. The filter is adapted to be self cleaning and the out filtered matter is disposed through the disposal channel  133 , either into the abdomen of the human patient, or into a container attached to the disposal channel  133 . Through the filtering of the lubricating fluid  128  the circulating lubricating system can operate for long periods without the need of any surgical procedures. 
     The medical device according to any of the embodiments could comprise at least one material selected from a group consisting of: polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA) and fluorinated ethylene propylene (FEP). It is furthermore conceivable that the material comprises a metal alloy, such as cobalt-chromium-molybdenum or titanium or stainless steel, or polyethylene, such as cross-linked polyethylene or gas sterilized polyethylene. The use of ceramic material is also conceivable, in the contacting surfaces or the entire medical device such as zirconium or zirconium dioxide ceramics or alumina ceramics. The part of the medical device in contact with human bone for fixation of the medical device to human bone could comprise a poorhouse structure which could be a porous micro or nano-structure adapted to promote the growth-in of human bone in the medical device for fixating the medical device. The porous structure could be achieved by applying a hydroxy-apatite (HA) coating, or a rough open-pored titanium coating, which could be produced by air plasma spraying, a combination comprising a rough open-pored titanium coating and a HA top layer is also conceivable. The contacting parts could be made of a self lubricated material such as a waxy polymer, such as PTFE, PFA, FEP, PE and UHMWPE, or a powder metallurgy material which could be infused with a lubricant, which preferably is a biocompatible lubricant such as a Hyaluronic acid derivate. It is also conceivable that the material of contacting parts or surfaces of the medical device herein is adapted to be constantly or intermittently lubricated. According to some embodiments the parts or portions of the medical device could comprise a combination of metal materials and/or carbon fibers and/or boron, a combination of metal and plastic materials, a combination of metal and carbon based material, a combination of carbon and plastic based material, a combination of flexible and stiff materials, a combination of elastic and less elastic materials, Corian or acrylic polymers. 
     Please note that any embodiment or part of embodiment as well as any method or part of method could be combined in any way. All examples herein should be seen as part of the general description and therefore possible to combine in any way in general terms.