Patent Publication Number: US-2021177625-A1

Title: Apparatus and methods for treatment of arthrosis or osteoarthritis in a joint of a mammal or human patient

Description:
BACKGROUND 
     The present invention relates generally to surgical treatment of joints. More particularly the invention relates to an apparatus and methods for treatment of arthrosis or osteoarthritis in a joint of a mammal or human patient. 
     Traditionally, surgical treatment of damaged joint surfaces (for example in the hip or knee joint) has implied a relatively complicated procedure. For example, in case of arthrosis in the hip joint, a substantial portion of the femoral bone is normally replaced with a prosthesis. This type of operation affects comparatively large muscles and/or many ligaments and tendons, which in turn, leads to a long period of convalescence for the patient. Moreover, if only the cartilaginous tissue of the joint is damaged, it is actually unnecessary to remove the healthy femoral bone tissue. 
     SUMMARY 
     The object is therefore to alleviate the above problems and provide an uncomplicated solution for treating arthrosis in joints, which minimizes the removal of healthy tissue and decreases the period of convalescence and the pain to the area of the joint. 
     According to one aspect, an apparatus for treatment comprises: a reservoir configured to hold a volume of a biocompatible material in liquid form having a temperature higher than 100° C. outside of a body containing a joint to be treated, and an instrument having a general tube shape, a distal end of the instrument being configured to be inserted into the joint, a proximal end of the instrument being connected to the reservoir and configured to receive the liquid material there from, the instrument being configured to feed the liquid material having a temperature higher than 100° C. from the proximal end to the distal end for deposition on at least one damaged surface of the joint, such that adjacent nerves are damaged by the heat of the material, the material being configured to assume a solid form under predefined conditions, and when in the solid form the material having a resistance to wear adapted to replace a worn out joint surface. 
     According to one embodiment, the apparatus further includes a flexible and collapsible mould member. This member has a pre-produced shape adapted to a shape and size of at least one of the at least one damaged surface. Thus, the mould member may contact and cover this joint surface. Additionally, the mould member is configured to be inserted into the joint, and be form-fitted to said damaged surface. The mould member is also configured to be connected to the distal end of the instrument, and when placed in the joint (J) receive the material in liquid form being fed through the instrument. The mould member has an internal volume configured to be filled with liquid material received via the instrument. Moreover, the mould member is configured to enable the predefined conditions for accomplishing a transition from the liquid form to the solid form after that the mould member has been filled with the liquid material. 
     The mould member is advantageous, since it facilitates targeting a predetermined volume of the liquid material to a specific joint surface both in terms of thickness and lateral coverage. 
     According to another aspect, the object is achieved by a method for treatment of arthrosis in a joint of a mammal or human patient. The method involves feeding a volume of a bio compatible material in liquid form into a reservoir located outside of a body containing a joint to be treated. The method further involves inserting into the joint an instrument having a general tube shape. A distal end of the instrument is configured to be inserted into the joint, and a proximal end of the instrument is connected to the reservoir. The method further involves receiving the liquid material from the reservoir in the instrument, and feeding the liquid material from the proximal end to the distal end of the instrument. Thereafter, the material is deposed on at least one damaged surface of the joint. Analogous to the above, the material is configured to assume a solid form under predefined conditions, and when in the solid form the material has a resistance to wear adapted to replace a worn out joint surface. In further analogy to the above, irregularities may be repaired on one or both of the opposing surfaces in the joint. 
     According to yet another aspect, the object is achieved by a surgical method for treatment of arthrosis in a joint of a mammal or human patient. This method involves inserting in a first position an arthroscopic instrument into a joint to be treated. The instrument here includes a camera for viewing the joint. This method further involves providing a reservoir with a volume of a biocompatible material in liquid form outside of a body containing the joint. Moreover, the method involves inserting into the joint an instrument having a general tube shape. A distal end of the instrument is configured to be inserted into the joint, and a proximal end of the instrument is connected to the reservoir. Additionally, the method involves receiving the liquid material from the reservoir in the instrument, and feeding the liquid material from the proximal end to the distal end of the instrument. Then, the material is deposed on at least one damaged surface of the joint. The material is configured to assume a solid form under predefined conditions, and again, when in the solid form the material has a resistance to wear adapted to replace a worn out joint surface. Naturally, here, the camera facilitates execution of the method. 
     According to a additional aspect, the object is achieved by a surgical method for treatment of arthrosis in a joint of a mammal or human patient. The method involves inserting in a first position an arthroscopic instrument into a joint to be treated. Here, the instrument includes a camera for viewing the joint. The method further involves inserting in at least one second position at least one surgical instrument into the joint. Moreover, the method involves providing a reservoir with a volume of a biocompatible material in liquid form outside of a body containing the joint. The method further involves inserting into the joint an instrument having a general tube shape. A distal end of the instrument is configured to be inserted into the joint, and a proximal end of the instrument is connected to the reservoir. Furthermore, the method involves inserting a mould member into the joint. The mould member has a pre-produced shape adapted to a shape and size of at least one damaged surface of the joint, so as contact and cover this surface when the mould member is placed in the joint. The mould member is also flexible, collapsible and has an internal volume configured to be filled with liquid material received via the instrument. The mould member is connected to the distal end of the instrument. The method further involves form-fitting the mould member to said at least one damaged surface, injecting the material into the mould member through the instrument, and receiving the material in the mould member. Then, after that the mould member has been filled with the liquid material, the material is caused to transition from the liquid form to a solid form. When in the solid form the material has a resistance to wear adapted to replace a worn out joint surface. 
     Here, the mould member facilitates targeting a predetermined volume of the liquid material to a specific joint surface both in terms of thickness and lateral coverage. Hence, an even better end result may be attained. 
     According to yet another aspect, the object is achieved by a surgical method for treatment of arthrosis in a joint of a mammal or human patient. The method involves inserting in a first position an arthroscopic instrument into a joint to be treated. Again, the instrument includes a camera for viewing the joint. The method further involves inserting in at least one second position at least one surgical instrument into the joint. A reservoir is provided with a volume of a biocompatible material in liquid form outside of a body containing the joint. The method also involves inserting into the joint an instrument having a general tube shape. A distal end of the instrument is configured to be inserted into the joint, and a proximal end of the instrument is connected to the reservoir. Furthermore, the method also involves inserting a mould member into the joint. The mould member has a pre-produced shape adapted to a shape and size of at least one of the damaged surface, so as contact and cover the damaged surface when the mould member is placed in the joint. Additionally, the mould member is flexible, collapsible and has an internal volume configured to be filled with liquid material received via the instrument. The mould member is connected to the distal end of the instrument. The mould member is also form-fitted to the damaged surface, the material is injected into the mould member through the instrument, the material is received in the mould member. Then, after that the mould member has been filled with the liquid material, the method involves causing a transition of the material from the liquid form to a solid form. When in the solid form the material having a resistance to wear adapted to replace a worn out joint surface. 
     Preferably, the mould member is designed to be at least partially removed after that the biocompatible material has become solid, and the method involves removing (at least partially) the mould member from the joint at an appropriate stage of the procedure. Alternatively, the mould member may be configured to disintegrate automatically, e.g. in connection with the material becoming solid. 
     According to still another aspect, the object is achieved by a method for surgically placing the above-proposed apparatus in a patient via a laparoscopic abdominal approach. The method involves inserting a tube-shaped instrument into the abdomen of the patient&#39;s body. The method also involves supplying gas into the patient&#39;s abdomen via the tube-shaped instrument, so as to expand the patient&#39;s abdominal cavity. At least two laparoscopic trocars are placed in the patient&#39;s body, and a camera is inserted through one of the laparoscopic trocars into the patient&#39;s abdomen. Additionally, the method involves inserting at least one dissecting tool through one of the at least two laparoscopic trocars. The method further involves dissecting a bone area opposite to the hip region. At least one hole is drilled in the bone of the patient from the abdomen reaching the hip joint, and through this at least one hole surgery and treatment are performed for treating arthrosis or osteoarthritis of the hip by using the proposed apparatus. This approach is advantageous, since it provides convenient access to the hip joint, while leaving the musculature surrounding the hip joint essentially intact. 
     According to a further aspect, the object is achieved by a method for surgically placing the above-proposed apparatus in a patient via a femoral bone approach. This method involves cutting the patient&#39;s skin at the lateral upper femoral region, and drilling at least one hole in the bone of the patient through the upper femoral region reaching the hip joint. Surgery and treatment for treating arthrosis or osteoarthritis of the hip is then performed through this at least one hole by using the proposed apparatus. Hence, a damaged hip joint can be treated in a very straightforward manner, which causes a low degree of discomfort to the patient. Also in this case, the musculature surrounding the hip joint is at most insignificantly influenced. 
     In any of the embodiments the material could comprise at least one material selected from the group consisting of: polytetrafluoroethylene, perfluoroalkoxy, fluorinated ethylene propylene, polyethylene, and acrylic polymer mixed with alumina trihydrate. 
     One advantage is that very small incisions is required. Thus, the healing process after the surgery can be made relatively short. Moreover, no healthy bone tissue is removed unnecessarily. Further advantages, beneficial features and applications will be apparent from the following description and the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are now to be explained more closely, which are disclosed as examples, and with reference to the attached drawings. 
         FIG. 1  schematically illustrates an apparatus according to one embodiment; 
         FIG. 2  illustrates how the hip joint of a patient may be reached according to two embodiments; 
         FIG. 3  schematically illustrates how a mould member adapted to a first joint surface is connected to the proposed apparatus according to a first embodiment; 
         FIG. 4  schematically illustrates how a mould member adapted to a second joint surface is connected to the proposed apparatus according to a second embodiment; 
         FIG. 5  illustrates how the knee joint of a patient may be treated according to one embodiment; 
         FIG. 6  illustrates how laparoscopic/arthroscopic trocars are approaching the hip joint from the abdominal side of the pelvic bone; 
         FIG. 7  illustrates how a hole is being created in the pelvic bone from the abdominal side thereof; 
         FIG. 8  illustrates how a small hole is being created in the pelvic bone from the abdominal side thereof; 
         FIG. 9  illustrates how a hole is being created in the femoral bone from the lateral side of the patient; 
         FIG. 10  illustrates how a hole has been created in the hip joint capsule. 
         FIG. 11 a    shows a mould placing instrument. 
         FIG. 11 b    shows a mould placing instrument. 
         FIG. 11 c    shows a mould placing instrument; 
         FIG. 12  shows the insertion of a mould; 
         FIG. 13 a    shows the insertion of a mould; 
         FIG. 13 b    shows the insertion of a mould; 
         FIG. 13 c    shows the filling of a mould; 
         FIG. 13 d    shows the hip joint in section after the mould has been filled; 
         FIG. 14  shows the placing of a mould in the knee joint; 
         FIG. 15  shows the placing of a mould in the knee joint; 
         FIG. 16  shows the filling of a mould in the hip joint; 
         FIG. 17  shows the filling of a mould in the hip joint; 
         FIG. 18  shows the filling of a mould in the hip joint; 
         FIG. 19  shows the hip joint in section after the mould has been filled; 
         FIG. 20  shows a medical device for injecting a fluid. 
     
    
    
     DETAILED DESCRIPTION 
     We refer initially to  FIG. 1 , which schematically illustrates an apparatus for treatment of arthrosis in a joint according to one embodiment. Typically, the joint is included in a human patient. However, technically, any other mammal may equally well be treated by means of this apparatus, e.g. a horse. 
     The apparatus includes a reservoir  110  and an instrument  120 . The reservoir  110  is configured to hold a volume of a biocompatible material in liquid form outside of a body containing a joint to be treated. The biocompatible material in the reservoir  110  is initially liquid. However, under predefined conditions the material is configured to assume a solid form. For instance, the material may be liquid when its temperature is above a certain level, and solid otherwise; or it may be liquid until it is exposed to a specific type of radiation, say ultraviolet light. These aspects will be elaborated below. In any case, when in the solid form the material has a resistance to wear adapted to replace a worn out joint surface. 
     The instrument  120  has a general tube shape, which may be substantially more elongated than what is apparent from the examples shown in  FIG. 1 . The instrument  120  may also be articulated (i.e. including one or more links), so as to enable a more convenient access to joint surfaces inside the body. Irrespective of the length and specific design of the instrument  120 , a distal end D thereof  120  is configured to be inserted into the joint to be treated. A proximal end P of the instrument  120  is connected to the reservoir  110  and configured to receive the material in liquid form from the reservoir  110 . The instrument  120  is further configured to feed the liquid material from the proximal end P to the distal end D, such that the material can be deposed on at least one damaged joint surface. This instrument could also be inserted into the joint via an arthroscopic trocar i.e. inside another tube, wherein the end of the instrument could be more flat. 
     According to one embodiment, it is presumed that the biocompatible material in the reservoir  110  is liquid because it has an elevated temperature (i.e. above 37 degrees Celsius), say 50, 70, 90, 100, 150, 200, 300 or 400 degrees Celsius, or any other temperature within an interval from 37 to 500 degrees Celsius. Therefore, the reservoir  110  is configured to hold the biocompatible material at the temperature in question, i.e. 50, 70, 90, 100, 150, 200, 300, 400 degrees Celsius or more. To this aim, the reservoir  110  preferably includes at least one shield member  115 , which is configured to isolate the reservoir  110  from the patient&#39;s body. Naturally, if the biocompatible material in the reservoir  110  is hot, the material will be hot also when passing through the instrument  120 . Hence, the instrument  120  preferably likewise includes at least one shield member  125  configured to isolate the body from liquid material. The material being injected at a high temperature will damage the adjacent nerves, thereby reducing the pain to the area of the joint. Suitable biocompatible materials being liquid at an elevated temperature, and that become solid when cooling off, may comprise fluoropolymers, e.g. in the form of polytetrafluoroethylene, perfluoroalkoxy and/or fluorinated ethylene propylene. 
     According to another embodiment, it is presumed that the biocompatible material in the reservoir  110  contains two different components. Each of these components is liquid when isolated from the other component. However, when the components are mixed in predefined proportions they develop a solid material. Hence, the two components may represent a hardenable component and a hardening agent respectively. In this embodiment, the reservoir  110  is configured to hold the two components separated from one another during an initial phase of a treatment. During a surgery phase subsequent to the initial phase, the reservoir  110  is configured to mix the two components into a mix. Here, the components are mixed in such proportions that the mix remains liquid during a period required to feed the mix through the instrument  120  to the at least one damaged joint surface in the joint to be treated. Moreover, the instrument  120  is configured to enable such a conveying of the mix. 
     According to another embodiment, it is presumed that the biocompatible material in the reservoir  110  is liquid due to the fact that the material has not yet been exposed to a specific type of radiation. For example, the material is configured to be liquid if it has been exposed to electromagnetic radiation whose intensity in a predefined spectrum is below a first predefined energy level per unit volume; and the material is configured to be solid if it has been exposed to electromagnetic radiation whose intensity in the predefined spectrum is above a second predefined energy level per unit volume. Here, the apparatus includes an electromagnetic radiation source, which is configured to convey electromagnetic radiation in the predefined spectrum to the at least one damaged joint surface via the instrument  120 . Thus, by activating the radiation source after deposition of biocompatible material on the joint surface, the material may be caused to transition from the liquid form to a solid form. 
     According to another embodiment, it is presumed that the biocompatible material in the reservoir  110  is liquid due to the fact that the material has not yet been exposed to a specific type of mechanical energy. For example, the biocompatible material may be configured to be liquid when it has been exposed to ultrasonic energy in a predefined spectrum whose intensity is below a first predefined energy level per unit volume; and be solid when it has been exposed to ultrasonic energy in the predefined spectrum above a second predefined energy level per unit volume. Here, the apparatus includes an ultrasound source configured to convey ultrasonic energy in the predefined spectrum to the at least one damaged joint surface via the instrument  120 . Thus, by activating the ultrasound source after deposition of biocompatible material on the joint surface, the material may be caused to transition from the liquid form to a solid form. 
     Preferably, since the biocompatible material will be deposed in a patient&#39;s body, the reservoir  110  and the connection between the reservoir  110  and the instrument  120  are configured to maintain the material sterile throughout the entire procedure. 
     Furthermore, according to all aspects, it is advantageous if the apparatus includes a light source  130  configured to illuminate the joint being treated during deposition of the liquid material on at least one damaged surface of this joint. 
       FIG. 2  illustrates how a damaged surface S of the hip joint J of a patient is reached according to two embodiments. In both cases the joint J is accessed through at least one bone of the body, namely either by passing via the femoral bone  210  or the pelvis bone  220   
     For example, the distal end D of the proposed instrument  120  may be inserted into the hip joint J by passing via the pelvis bone  220  from inside the abdomen, as illustrated to the right. Here, for reasons of clarity,  FIG. 2  only shows the distal-most end D of the instrument  120  as a straight segment. However, of course, in order to reach the joint J, the instrument  120  may be provided with one or more links (not shown). According to one aspect, the apparatus is surgically placed in the patient via a laparoscopic abdominal approach, shown in  FIG. 6 . Specifically, this involves inserting the tube-shaped instrument  120  into the abdomen of the patient&#39;s body. Gas is then supplied into the patient&#39;s abdomen via the instrument  120 , so as to expand the abdominal cavity. At least two laparoscopic trocars are placed in the patient&#39;s body, and a camera is inserted through one of the laparoscopic trocars into the patient&#39;s abdomen. Moreover, at least one dissecting tool is inserted through one of the at least two laparoscopic trocars. The method further involves dissecting a bone area opposite to the hip region, and drilling at least one hole in the bone of the patient from the abdomen reaching the hip joint, e.g. as illustrated in  FIG. 2 . Surgery and treatment for treating arthrosis or osteoarthritis of the hip joint J is then performed through this hole by using the proposed apparatus. 
     Alternatively, the distal end D of the proposed instrument  120  may be inserted into the hip joint J by passing via the femoral bone  210  of the body, as illustrated to the left in  FIG. 2 . According to one aspect, the apparatus is surgically placed in the patient via a femoral bone approach, which involves the following. The patient&#39;s skin is cut at the lateral upper femoral region. Then, at least one hole is drilled in the bone of the patient through the upper femoral region reaching the hip joint J. Finally, surgery and treatment is performed through this at least one hole for treating arthrosis or osteoarthritis of the hip joint J by using the proposed apparatus. 
     Preferably, the step of drilling the at least one hole in the bone involves drilling the hole in such a way that a plug of bone is detached into the abdomen. Prior to completing the operation, the method further comprises replacing the plug. 
     The instrument  120  may also be configured to be inserted into the joint J by passing via a capsula of the joint J. 
     Irrespective of how the joint J is accessed for treatment of arthrosis therein, according to these embodiments, the method involves the following. A volume of a bio compatible material in liquid form is fed into the reservoir  110  of the apparatus. The reservoir  110  is located outside of a body containing a joint J to be treated. Then, the distal end D of the instrument  120  is inserted into the joint J, and the proximal end P of the instrument  120  is connected to the reservoir  110 . Subsequently, the liquid material from the reservoir  110  is received in the instrument  120 . Thereafter, the liquid material is fed from the proximal end P to the distal end D of the instrument  120 , such that the material is deposed on at least one damaged surface S of the joint J. Finally, the material is caused to transition from the liquid form to a solid form. When in the solid form, the biocompatible material has a resistance to wear adapted to replace a worn out joint surface. Namely, the material is configured to assume the solid form under predefined conditions, for instance in response to a temperature drop, or exposure to radiation. 
       FIG. 3  schematically illustrates how a mould member  140  adapted to a convex joint surface is connected to the proposed apparatus according to one embodiment. 
     In addition to the embodiment shown in  FIG. 1 , the apparatus of  FIG. 3  includes a flexible and collapsible mould member  140 . This member  140  has a pre-produced shape adapted to a shape and size of at least one damaged surface of a specific joint, for instance the surface S of the femoral head represented in  FIG. 2 . The shape and size of the at least one damaged surface may be determined via a magnetic resonance imaging investigation, a computer tomography x-ray investigation and/or via arthroscopy. The pre-produced shape of the mould member  140  renders it adapted to contact and cover the joint surface S. 
     Moreover, the mould member  140  is configured to be inserted into the joint J in question and be form-fitted to the damaged surface S. Depending on the location and type of joint, fitting the mould member  140  to the surface S may require a number of additional instruments (not shown). In any case, the mould member  140  is configured to be connected to the distal end D of the instrument,  120  and when placed in the joint J, receive the material in liquid form being fed through the instrument  120 . The mould member  140  has an internal volume that is configured to be filled with liquid material received via the instrument  120 . Furthermore, after that the mould member  140  has been filled with the liquid biocompatible material, the mould member  140  is configured to enable the predefined conditions, which are required to accomplish a transition of the biocompatible material from the liquid form to the solid form. 
     Analogous to the embodiments described above with reference to  FIG. 1 , the apparatus preferable includes a light source  130 , e.g. arranged in the instrument  120 , configured to illuminate the joint being treated during deposition of the liquid material in the mould member  140 . 
     It is further advantageous if an arthroscopic instrument being inserted into the joint along with the instrument  120  includes a camera for viewing the joint. 
     Equivalent to the instrument  120  as such, the mould member  140  is configured to be inserted into the joint J by passing via a bone  210  or  220  of the body. This may involve passing via a bone of the body from inside the abdomen, or passing via the femoral bone of the body. 
     According to some embodiments, the mould member  140  is preferably adapted to be withdrawn (at least partly) from the joint J after that the biocompatible material has assumed its solid form. 
       FIG. 4  schematically illustrates how a mould member  140  having a pre-produced shape adapted to a concave joint surface is connected to the proposed apparatus according to one embodiment. Here, all reference signs which also occur in  FIG. 1 or 3  designate the same components/features as those described above with reference to these figures. 
     According to one embodiment, the reservoir  110  is configured to hold the material at an elevated pressure level exceeding the normal atmospheric level. Thus, the mould member  140  may expand in response to receiving the material. Naturally, this is applicable to any configuration of the proposed mould member (i.e. not just the specific design shown in  FIG. 4 ). 
     Additionally, the apparatus may include an injection member  150  configured to inject the liquid material into the mould member  140  at the elevated pressure. Specifically, the material is injected into the mould member  140  through the instrument  120 . When the mould member  140  has been filled with liquid material, this material is caused to transition from the liquid form to the solid form. 
       FIG. 5  illustrates how the knee joint J of a patient may be treated according to one embodiment. Here, a mould member  140  is form-fitted to one of the joint surfaces of the femur bone facing the tibia bone  510 , for instance by means of the apparatus shown in  FIG. 3 . 
     Preferably, in this case, the distal end D of the instrument  120  is configured to be inserted into the joint J by passing via a capsula of the joint J. 
       FIG. 6  shows a lateral view of the body of a human patient, with the hip joint shown 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 femur 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  35  adapted to create a hole in the pelvic bone  9 , or instruments  36  for introducing, placing, connecting, attaching, creating or filling a mould or an injected fluid. 
       FIG. 7  shows an embodiment, wherein the mould is to be used for resurfacing the hip joint. For placing the mould in the hip joint the hip joint needs to be reached, this could be through a hole placed in the pelvic bone  9 , the femoral bone  7  or the hip joint capsule  12 .  FIG. 7  shows the hole  18  in the pelvic bone  9  according to a first embodiment, the hole  18  is large which allows the mould to pass through said hole  18  in its full functional size. 
       FIG. 8  shows the hole  20  according to a second embodiment wherein the hole  20  created in a surgical or laparoscopic method is much smaller allowing the surgical instrument creating the hole to be smaller, and thus the incision and dissection performed in the human body. To place the mould in the joint in this embodiment the mould needs to be flexible or collapsible. 
       FIG. 9  shows the hip joint in section when creating a hole in the femur bone  7 . The hole in the femur bone passes through the caput femur  5  into the hip joint and enables the surgeon to reach the hip joint. 
       FIG. 10  shows the hip joint in section when creating a hole in the hip joint capsule  12 . The hole in the hip joint capsule passes into the hip joint and enables the surgeon to reach the hip joint. 
       FIG. 11 a    shows an instrument for placing a mould  81  in the hip joint or the knee joint through a hole in the pelvic bone, the femur bone, the hip joint capsule or an area of the knee. The instrument comprises a piston  89  for transporting the mould  81  into the joint. 
       FIG. 11 b    shows a section of the surgical instrument comprising a tube like element  90  for housing of said mould  81 . 
       FIG. 11 c    shows the surgical instrument according to another embodiment in which the surgical instrument comprises a flexible or bent part  91  improving the reach of the surgical instrument. The surgical instrument according to any of the embodiments can be used to place said mould  81  inside of a joint in any of the ways described in the following embodiments. 
       FIG. 12  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 a surgical, or in a laparoscopic/arthroscopic method. 
       FIG. 13   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 femur 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 femur 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 femur bone  7  the mould  81  is inserted into the hip joint through the hole  82  using the surgical instrument  83  according to any of the embodiments above, as shown in  FIG. 13   b.    
       FIG. 13 c    shows the mould  81  when being inserted into the hip joint using the surgical instrument  83  adapted therefore. 
       FIG. 13 d    shows the mould  81  in place after insertion into the hip joint, the surgical instrument used to place said mould  81  in the hip joint is retracted after the insertion is completed. 
       FIG. 14  shows the placing of a mould  81  in a knee  214  in a surgical method. The mould  81  is placed using the surgical instrument according to any of the embodiments above. 
       FIG. 15  shows the placing of a mould  81  in a knee  214  in a laparoscopic/arthroscopic method. The mould  81  is placed using the surgical instrument according to any of the embodiments above. 
     After the mould has been placed in the hip or knee joint it is filled with a fluid adapted to harden to a medical device adapted to serve as at least one artificial joint surface. 
       FIG. 16  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  18  in the pelvic bone  9  from the opposite side from acetabulum  8 . The injecting member  92  comprises a piston  94  that pushes said fluid  93  into the mould  81 . 
       FIG. 17  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 femur bone  7 . The injecting member  92  comprises a piston  94  that pushes said fluid  93  into the mould  81 . 
       FIG. 18  shows the hip joint in section, wherein an injecting member injects a fluid  93  into a mould  81  in the hip joint through a hole in the hip joint capsule  12 . The injecting member  92  comprises a piston  94  that pushes said fluid  93  into the mould  81 . The fluid  93  is adapted to harden to create a medical device adapted to serve as at least one artificial hip joint surface. 
       FIG. 19  shows the hip joint in section wherein the medical device  93 ′ is located between the acetabulum  8  and the caput femur  5  which has been created by the hardening of the fluid  93  adapted to harden. Said medical device is adapted to serve as at least one artificial hip joint surface. The hole in the pelvic bone is preferably sealed with a bone plug  31  or a prosthetic part  98 . The mould  81  used to create the medical device  93 ′ has been removed. 
       FIG. 20  shows the injecting member  92  according to any of the embodiments above, adapted to inject fluid  93  into a mould  81  in the hip joint or the knee joint. The injecting member  92  could further be adapted to inject material  93  or a fluid  93  into 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  92  comprises a container  107  adapted to hold a fluid  93  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) said container  107  is adapted to keep said fluid sterile. According to a third embodiment (not shown) said container  107  is adapted to keep said fluid cold or hot and according to a fourth embodiment (not shown) said container  107  is adapted to keep said fluid in a dark environment. Furthermore a combination of the above mentioned embodiments is conceivable. 
     The term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components. However, the term does not preclude the presence or addition of one or more additional features, integers, steps or components or groups thereof. 
     The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any suggestion that the referenced prior art forms part of the common general knowledge in Australia, or in any other country. 
     The invention is not restricted to the described embodiments in the figures, but may be varied freely within the scope of the claims.