Source: https://patents.google.com/patent/US20050177167
Timestamp: 2018-02-21 07:47:51
Document Index: 418854741

Matched Legal Cases: ['art 1', 'art 2', 'art 4', 'art 5', 'art 7', 'art 9', 'art 10', 'art 19', 'art 20', 'art 28', 'art 29']

US20050177167A1 - Implantable screw for stabilization of a joint or a bone fracture - Google Patents
US20050177167A1
US20050177167A1 US11100844 US10084405A US2005177167A1 US 20050177167 A1 US20050177167 A1 US 20050177167A1 US 11100844 US11100844 US 11100844 US 10084405 A US10084405 A US 10084405A US 2005177167 A1 US2005177167 A1 US 2005177167A1
US11100844
US7625395B2 (en )
Muckter Helmut
A bone screw has a flexible shaft which prevents relative movements in the direction of tension, but permits smaller movements in all other directions. The bone screw is configured as a screw insertable into medullary cavities having a curved surface, where the screw adapts to the given contour.
This application is a continuation of prior filed copending U.S. application Ser. No. 10/174,906, filed Jun. 18, 2002, which claims the benefit of prior filed provisional application, Appl. No. 60/301,267, filed Jun. 27, 2001, pursuant to 35 U.S.C. 119(e), and which claims the priority of German Patent Application Serial No. 101 29 490.5, filed Jun. 21, 2001, pursuant to 35 U.S.C. 119(a)-(d).
The best known representative of the first group (rigid implants) is the so-called locking screw. When using this principle, the two partners in the joint are secured rigidly relative to one another by a direct screw connection, which guarantees congruence of the joint, but blocks relative movement of the joint. Similar functions are achieved by bridging the joint with Kirschner's wires, optionally supplemented by wire cerclage or by using rigid osteosynthesis plates (especially in the area of the pelvis).
Known representatives of the third group (screw-in implants with hooks) include hook plates proposed by Balser, Wolter or Dreithaler in a similar design for stabilization of ruptures of the acromioclavicular joint or the syndesmosis hooks developed by Engelbrecht (literature: E. Engelbrecht et al. (1971) “Syndesmosis hooks for treatment of tibio-fibular syndesmosis ruptures,” Chirurg 42:92) for stabilization of ruptures of the ankle joint. These implants allow good augmentation of the joint and essentially preserve mobility, but it is difficult to adjust the proper congruence of the joint, which can often be achieved only by bending the implant subsequently, because these implants do not have any suitable possibilities for adjustment. In addition, a relatively large surgical access area is required, which necessitates a greater surgical trauma.
FIG. 1 is a bone screw according to the present invention, whose shaft is configured for flexibillity as a wire cable or as a wire bundle;
FIG. 2 is a bone adjusting screw, whose shaft is configured for flexibility as a wire cable or as a wire bundle;
FIG. 3 is a bone screw, with a bone thread on the distal side from the head and whose shaft is configured for flexibility as a wire cable or as a wire bundle, with a bone thread at the proximal head side, which has a larger diameter and a smaller thread pitch than the bone thread distal from the head;
FIG. 4 is a screw, which has a bone thread on one side, with a shaft configured for flexibility as a wire cable, a cord or a wire bundle, and a bolt on the other side with a metal thread and a hexagon socket head nut screwed onto it;
FIG. 5 is a bone screw, whose shaft is configured to be flexible in the manner of a spiral spring;
FIG. 6 a is a bone screw, which is preferably made of a biocompatible plastic with a flexible shaft composed of multiple webs;
FIG. 6 b is a hexagon head wrench for use with the bone screw of FIG. 6 a;
FIG. 7 is a bone screw, wherein the shaft consists of multiple fibers which are anchored alternately in the head part and in the threaded part of the bone screw,
FIG. 8 is an embodiment of a bone screw according to the present invention for stabilization of the ankle joint (distal tibiofibular joint, syndesmosis);
FIG. 9 is a further embodiment for stabilization of the acromioclavicular joint;
FIG. 10 is another embodiment for stabilization of the iliosacral joint;
FIG. 11 is another embodiment for stabilization in the area of the wrist with scapholunate dissociation;
FIG. 12 is yet another embodiment for interfragmentary traction screws in the area of the patella with a fracture of the patella;
FIG. 13 is a bone screw according to FIG. 4, where the wire cable or the wire bundle is reinforced by individual sleeves.
Turning now to the drawing, and in particular to FIG. 1, there is shown a bone screw, whose head part 1 and whose threaded part 2 are flexibly interconnected by a wire cable or a wire bundle 3. The wire cable or the wire bundle is fixedly connected in the head part as well as in the threaded part through suitable connection methods (e.g., pressed, glued, soldered or welded connections). The use of a wire cable or a wire bundle allows the application of tensile forces and the transfer of torsion moments by way of a flexible shaft. Compressive forces, transverse forces or bending moments, however, are transmitted only to a slight extent.
FIG. 2 shows a bone locking screw which has a head part 4, which is provided with a bone thread, and a threaded part 5, which are flexibly interconnected by a wire cable or wire bundle 6 analogeous to FIG. 1. The thread on the head part and the threaded part are of the same size and the thread flanks are the same. In this way, a previously defined distance between two bones to be joined is established, regardless of the tightening torque of the screw.
FIG. 3 shows a bone screw with a thread-bearing head part 7, which is flexibly connected to threaded part 9 by a wire cable or a wire bundle 8 analogous to FIG. 1. According to the known function principle of the Herbert screw, the thread on the head part has a larger diameter in comparison with the threaded part and it has a smaller thread pitch. When this screw is screwed into a fractured bone perpendicular to the plane of the fracture, the two fragments are moved toward one another and are braced against one another, where the extent of the movement toward one another per revolution of the screw is obtained from the difference between the two thread pitches.
FIG. 4 shows a screw which has a threaded part 10 on one side with a bone thread which is connected flexibly by a wire cable, a wire bundle or a cord 11 to a bolt 12, which has a metal or plastic thread. A hexagon socket head nut 13 is screwed onto this bolt. In implantation of such a screw, first the threaded part with the bone thread is screwed into the bone by way of a stud bolt. This is done by means of a cannulated wrench which is pushed over the wire cable or the wire bundle or the cord and the bolt and meshes with the hexagon insert bit 14 of the threaded part. Then the hexagon socket head nut is screwed onto the bolt with a metal thread by means of a cannulated hexagon socket wrench. Next, the wire cable or wire bundle that projects on the hexagon socket or the projecting cord is shortened with a knife forceps.
FIG. 5 shows a variation of a bone screw 15, whose shaft 16 is designed in the form of a spiral. In addition to the flexibility of the shaft, an elastic component is added in this variation. The amount of flexibility and elasticity of the shaft depends to a great extent on the design of the spiral. Large spirals have only a low flexibility and elasticity, whereas small spirals are highly elastic and flexible. Such a design variant is especially suitable for intramedullary screwing of bones with curved surfaces, e.g., as so-called creep screws in the area of the pelvis. The shaft length is limited by a wire cable, a wire bundle, a chain, a fiber or a flexible pin (not shown), preferably arranged in the spiral.
FIG. 6 a shows a bone screw 17, which is preferably suitable for being fabricated from absorbable or non-absorbable plastics and is designed so that it can be manufactured by the casting technology. The flexibility of the shaft here is achieved due to the fact that it consists of multiple webs 18. The extent of the flexibility of this variant is defined by the number and dimensions of the webs and by the material properties of the material used. Since the webs are capable of transmitting the torsion moments which occur in tightening the screw only to a very limited extent, it is especially advantageous if a hexagon head 21, 22 (or a different type of wrench socket) is provided in both the threaded part 19 and the head part 20, so that a torsion load on the webs is prevented when using a corresponding stepped hexagon head wrench according to FIG. 6 b. Likewise, it is advantageous for many applications if the threaded part is cannulated 23, so that application of the screw can take place through a corresponding guide wire.
FIG. 7 shows a bone screw 24, which is equally suitable for fabrication from an implant metal as well as from absorbable or non-absorbable plastics and which is designed so that the individual components can be manufactured by the casting technology. The flexibility of the shaft is achieved by the fact that it consists of multiple fibers 25 which are either held in eyelets 26, 27, anchored alternately in the head part 28 and in the threaded part 29 of the screw according to the figure or are each securely anchored in the head part and in the threaded part. Since this variant can transmit only tensile forces, a hexagon head socket 30, 31 (or a different type of wrench socket) is to be provided in both the head part and in the threaded part, analogeous to FIG. 6 a, permitting the use of a stepped wrench according to FIG. 6 b, with which the head part and threaded part can be screwed equally into the bone.
FIG. 8 shows an embodiment of a bone screw with a flexible shaft 32 according to FIG. 4, which is introduced into the area of the ankle for augmentation of a ruptured syndesmosis 33 (syndesmosis=ligament connection between the fibula 34 and the tibia 35 in the area of the ankle joint). In contrast with a conventional rigid screw connection, the natural relative movement between the fibula and tibia is preserved due to the flexible shaft. However, it is impossible for the ankle to yield, which would lead to instability of the ankle bone 36. The dimensions of the bone screw are selected so that it can be introduced into the bone through the boreholes in a conventional osteosynthesis plate when there is a concomitant fracture of the lateral malleolus.
FIG. 9 shows another embodiment of a bone screw with a flexible shaft 37 according to FIG. 1 in the area of the ligament connection between the shoulder blade 38 and the collar bone 39, on the acromioclavicular joint 40. The rupture of all three ligaments involved in this connection is diagramed schematically (acromioclavicular ligament 41, trapezoid ligament 42, conoid 43). According to the principle described in 1941 by Bosworth for the use of rigid screws, the screw is screwed into the coracoid process 44 through the collar bone. In contrast with a conventional rigid screw connection, the natural relative movement between the collar bone and the shoulder blade is maintained due to the flexible shaft. However, a high position of the collar bone, which would lead to incongruence of the acromioclavicular joint, is impossible.
FIG. 10 shows another embodiment of a bone screw having a flexible shaft 45 according to FIG. 4 in the area of the ligament connection between the sacrum 46 and the iliac bone 47 (iliosacral joint 48). In the case of an instability of the posterior pelvic ring due to injury, stabilization is accomplished by screwing one or more screws with a flexible shaft into the bone. In contrast with a conventional rigid screw connection, the natural relative movement between the sacrum and the ileum is preserved due to the flexible shaft. However, gaping of the joint gap is reliably prevented due to the screw having a flexible shaft.
FIG. 11 shows another embodiment of a bone screw having a flexible shaft 49 according to FIG. 4 in the area of the wrist in the case of a ruptured ligament between the scaphoid bone 50 and the lunate bone 51 (scapholunate dissociation). Repositioning and stabilization are accomplished by screwing a screw having a flexible shaft into the bone. In contrast with a conventional rigid screw connection or stabilization with Kirschner's wires, the natural relative movement between the scaphoid bone and the lunate bone is preserved due to the flexible shaft. However, the wrist bones that have been screwed together cannot yield laterally.
FIG. 12 shows another embodiment of bone screws with a flexible shaft 52, 53 according to FIG. 1 with a transverse fracture of the patella 54. According to the known tension belt principle, the tensile forces conducted from the quadriceps tendon over the patella and into the patellar tendon are transferred through the two bone screws with a flexible shaft and the two fragments of the patella are compressed together.
FIG. 13 shows a bone screw according to FIG. 4, where wire cable or wire bundle is reinforced by individual sleeves 55. In accordance with their winding, wire cables tend to twist and coil up when a torsion moment is introduced in the opposite direction to their winding. Due to the fact that sleeves or a spiral are pushed onto the wire cable or the wire bundle, this twisting can be limited, and at the same time, a stabilization of the wire cable can be achieved due to the resulting clamping of the wire cable in the sleeve or the spiral. This allows higher torsion moments to be transmitted than is possible with an unreinforced wire cable or wire bundle. In addition, depending on the design of the sleeve and the spacing of the individual sleeves or spiral windings relative to one another, the extent of the bending of the flexible screw shaft can be limited.
1. A screw implant for stabilization of a joint or a bone fracture, comprising a screw including a head portion on one end, a threaded portion on another end, and a shaft portion extending between the head portion and the threaded portion and defining an axis, wherein the shaft portion is constructed in the form of several strands and has a flexibility that maintains a natural movement of bone participants in an area of the joint or bone facture but prevents a movement in a direction of the axis away from one another.
2. The screw implant of claim 1, wherein the shaft portion is a wire cable comprised of several wire strands.
3. The screw implant of claim 1, wherein the shaft portion is a rope or cord.
4. The screw implant of claim 1, wherein the threaded portion includes a bone thread and a nut connected in one piece with the bone thread for attachment of an external wrench to screw the threaded portion into one of the bone participants.
5. The screw implant of claim 4, wherein the nut is a hexagon nut.
6. The screw implant of claim 4, wherein the head portion is a bolt having a socket for attachment of an external wrench for securement of the head portion in the other one of the bone participants.
7. The screw implant of claim 6, wherein the socket is a hexagon socket.
8. The screw implant of claim 4, wherein the head portion includes a bolt connected to the shaft portion and a nut screwed onto the bolt and provided for attachment of an external wrench for securement of the head portion in the other one of the bone participants.
9. The screw implant of claim 1, and further comprising a reinforcement placed from outside over the shaft portion.
10. The screw implant of claim 9, wherein the reinforcement is at least one sleeve or a spiral.
11. The screw implant of claim 1, wherein the screw is made from a material selected from the group consisting of biocompatible metal, biocompatible absorbable plastic, biocompatible non-absorbable plastic, and a combination thereof.
12. The screw implant of claim 1, wherein the screw forms a unitary structure before implantation.
US11100844 2001-06-21 2005-04-07 Implantable screw for stabilization of a joint or a bone fracture Active 2024-09-05 US7625395B2 (en)
DE2001129490 DE10129490A1 (en) 2001-06-21 2001-06-21 Implantable screw for stabilization of joint or bone fracture, has flexible shaft which interconnects proximal head portion and distal insertion portion of elongated screw body
DE10129490.5 2001-06-21
US30126701 true 2001-06-27 2001-06-27
US10174906 US20020198527A1 (en) 2001-06-21 2002-06-18 Implantable screw for stabilization of a joint or a bone fracture
US11100844 US7625395B2 (en) 2001-06-21 2005-04-07 Implantable screw for stabilization of a joint or a bone fracture
US20050177167A1 true true US20050177167A1 (en) 2005-08-11
US7625395B2 US7625395B2 (en) 2009-12-01
ID=27214480
US10174906 Abandoned US20020198527A1 (en) 2001-06-21 2002-06-18 Implantable screw for stabilization of a joint or a bone fracture
US11100844 Active 2024-09-05 US7625395B2 (en) 2001-06-21 2005-04-07 Implantable screw for stabilization of a joint or a bone fracture
US (2) US20020198527A1 (en)
FR2894454A1 (en) * 2005-12-13 2007-06-15 Maurice Bergoin Implant for realizing arthrodesis, has median hole receiving pedicle screw along convergent angle with respect to sagittal plane, and lateral hole receiving ilio-sacral screw, where latter screw is fixed on implant by locking screw
CN105611885A (en) * 2014-08-11 2016-05-25 瑞特医疗技术公司 Flexible screw and methods for syndesmosis repair
GB201601443D0 (en) 2013-07-03 2016-03-09 Acute Innovations Llc And Acumed Llc Steerable fastener for bone
RU2551303C1 (en) * 2013-11-13 2015-05-20 Государственное автономное учреждение здравоохранения "Республиканская клиническая больница Министерства здравоохранения Республики Татарстан" Method of treating compound pronation-eversional fractures of distal knee joint
CN105496531B (en) * 2016-02-04 2017-11-28 宝楠生技股份有限公司 Fibula after truncation fixing means fixed to the tibia
US20170247189A1 (en) * 2016-02-29 2017-08-31 Fenner U.S., Inc. Conveyor belt connector and method for forming a belt
US20020198527A1 (en) 2002-12-26 application
US7625395B2 (en) 2009-12-01 grant
Owner name: NOVOPLANT GMBH, GERMANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HILDINGER, KARL-HEINZ;MUECKTER, HELMUT;REEL/FRAME:022210/0746