CN210185775U

CN210185775U - Joint head prosthesis assembly and artificial joint

Info

Publication number: CN210185775U
Application number: CN201820016569.0U
Authority: CN
Inventors: Yu Liu; 刘雨
Original assignee: Beijing Montagne Medical Device Co Ltd
Current assignee: Beijing Montagne Medical Device Co Ltd
Priority date: 2018-01-05
Filing date: 2018-01-05
Publication date: 2020-03-27
Anticipated expiration: 2028-01-05

Abstract

The present application provides an articulating head prosthesis assembly comprising: the body comprises a first end and a second end, wherein the first end and the second end extend along the axial direction, the outer surface of the first end is a spherical surface, and the second end is provided with a concave part; wherein the articular head prosthesis assembly further comprises: a bushing, at least a portion of the bushing being configured to be received within the recess such that the body and the bushing are adjustable in axial relative position to one another; and a fixing part configured to fix or release the body and the bushing. The application also relates to an artificial joint comprising the joint head prosthesis assembly. The self length of the joint head prosthesis component is adjusted or the physiological neck length is automatically adapted, so that the neck length of the newly formed joint combination is consistent with the physiological neck length, risks such as dislocation of the joint prosthesis, pain of a patient and the like caused by inconsistency are eliminated, and the operation quality is improved.

Description

Joint head prosthesis assembly and artificial joint

Technical Field

The application relates to the technical field of medical instruments, in particular to a joint head prosthesis component for artificial joint replacement.

Background

For severe joint diseases, when conservative treatment is ineffective or not effective significantly, the most effective treatment is joint replacement. By replacing the affected partial or total joint with the artificial prosthesis component, joint pain can be effectively relieved, joint stability can be maintained, joint function can be improved, and the like. The complexity of joint replacement requires that the prosthetic components not only have good material properties, such as biocompatibility, corrosion resistance, high strength, etc., but also have good combined mechanical properties, structural matching, etc., so as to avoid the phenomena of stress concentration, stress distribution imbalance, etc., which are generated after the prosthesis is implanted into a living body, and damage the normal joint biomechanical distribution rule, thereby causing a series of complications such as postoperative bone resorption, bone atrophy, prosthesis loosening, etc.

Taking hip joint replacement as an example, the femoral head prosthesis component used clinically is a surgical implant of the femoral head part of the hip joint of a human body, the shape is mostly spherical, and the material mostly adopts titanium alloy or cobalt chromium molybdenum alloy material with biocompatibility. In total hip arthroplasty, a femoral head prosthesis component is in taper fit with a femoral stem prosthesis on one side of a femur and is in fit with a acetabular cup prosthesis on one side of an acetabulum to form a spherical hinge structure so as to replace a diseased femoral head or a physiological acetabulum and form a new joint combination. For the newly formed joint combination, the distance from the center of the femoral head to the femoral base is called the neck length. The neck length of the newly formed joint combination should be consistent with the physiological neck length. However, in practice, the femoral head prosthesis component itself is fixed in length, and due to the complex structure of the human body, the neck length of the newly formed joint combination after replacement is not necessarily guaranteed to be completely consistent with the physiological neck length. If the neck length of the newly formed joint combination is too small, the femoral head prosthesis component is easy to dislocate, and conversely, if the neck length of the newly formed joint combination is too large, postoperative pain can be caused, and troubles can be caused to postoperative life of patients.

Similar problems occur in the replacement of the joint head prosthesis components of shoulder joints or other bone joints with sockets.

Therefore, there is a need for an articulating head prosthesis assembly that is capable of adjusting its length and accommodating physiologic neck length.

SUMMERY OF THE UTILITY MODEL

The purpose of this application is to overcome at least one kind of defect that exists among the prior art, proposes a joint head prosthesis subassembly for artificial joint replacement, and this joint head prosthesis subassembly can utilize simple structure to realize the adjustment of self length to adapt to physiology neck length, improve operation quality.

To this end, according to an aspect of the present application, there is provided an articular head prosthesis assembly comprising: the body comprises a first end and a second end, wherein the first end and the second end extend along the axial direction, the outer surface of the first end is a spherical surface, and the second end is provided with a concave part; wherein the articular head prosthesis assembly further comprises: a bushing, at least a portion of the bushing being configured to be movably received within the recess such that the body and the bushing are adjustable in axial relative position to one another; and a fixing part configured to fix or release the body and the bushing.

Preferably, the inner surface of the recess is provided with an internal thread and the outer surface of the bushing is provided with an external thread, such that the body can be rotated relative to the bushing to adjust the axial relative position.

Preferably, the inner surface of the recess is cylindrical and the outer surface of the bush is cylindrical, such that the body can slide relative to the bush to adjust the axial relative position.

Preferably, the articular head prosthesis assembly further comprises a resilient member disposed within the recess and between the body and the bushing.

Preferably, at least one end of the bushing is open, and an inner surface of the bushing is tapered.

Preferably, the fixing member is at least one screw, and the second end of the body is provided with a projection provided with at least one threaded through hole for receiving the fixing member.

Preferably, the screw is a full thread socket head cap screw.

Preferably, the elastic member is at least one of a coil spring and a leaf spring.

Preferably, the articulating head prosthesis assembly is a femoral head prosthesis assembly for hip arthroplasty.

According to another aspect of the present application, there is provided an artificial joint comprising an articulating head prosthesis assembly as described above.

According to the application, the joint head prosthesis component comprises a body and a lining which can adjust the axial relative position of the body and the lining, so that the length of the joint head prosthesis component can be adjusted, and the neck length of the newly formed joint combination is ensured to be consistent with the physiological neck length, so as to realize the final implantation effect.

Drawings

Exemplary embodiments of the present application are described in detail below and are further explained with reference to the attached drawing figures, wherein:

fig. 1 is a schematic cross-sectional view of a joint head prosthesis assembly according to an exemplary embodiment of the present application, wherein the joint head prosthesis assembly is assembled with a cup prosthesis and a stem prosthesis;

fig. 2 is a schematic cross-sectional view of an articulating head prosthesis assembly according to another exemplary embodiment of the present application, wherein the articulating head prosthesis assembly is assembled with a stem prosthesis;

fig. 3 is an enlarged partial cross-sectional view of the articulating head prosthesis assembly shown in fig. 1 and 2, showing the fixation components.

Detailed Description

Preferred embodiments according to the present application are described in detail below with reference to the accompanying drawings and examples.

In the figures, other components have been omitted for the sake of brevity, but this does not indicate that the articular head prosthesis assembly of the present application may not include other components. In addition, it should be understood that the drawings are merely illustrative of the present application and that the size, proportion and number of components are not intended to limit the present application. In different drawings, the same or similar components are denoted by the same reference numerals.

In a preferred embodiment of the present application, the present application is described in terms of a femoral head prosthesis component for use in an artificial hip replacement. However, it will be understood by those skilled in the art that these exemplary embodiments are not meant to limit the application in any way, for example, the prosthesis of the present application may be used as a joint head prosthesis assembly for other artificial joints with a joint socket, such as shoulder joints. Furthermore, the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

Referring initially to fig. 1, fig. 1 is a schematic cross-sectional view of an articulating head prosthesis assembly according to an exemplary embodiment of the present application. As shown in fig. 1, the joint head prosthesis assembly of the present application is assembled with a cup prosthesis 40 and a stem prosthesis 50. The articular head prosthesis assembly comprises a body 10, a bushing 20 and a fixation component 30. The spherical outer surface of the body 10 is fitted with the inner surface of the socket of the cup prosthesis 40 to form a spherical hinge structure, and the bush 20 is fixedly coupled with the stem prosthesis 50. The body 10 and the bush 20 can be adjusted in axial relative position to each other and fixed in the adjusted position by the fixing member 30.

According to an embodiment of the present application, the body 10 comprises a first end and a second end extending in an axial direction, which is referred to as the long axis direction of the articular head prosthesis assembly. The outer surface 11 of the first end of the body 10 is a spherical surface to be matched with the inner surface of the socket of the acetabular cup prosthesis 40 to form a spherical hinge structure. The second end of the body 10 is provided with a recess 15, the recess 15 being configured to movably receive at least a portion of the bushing 20 such that the body 10 and the bushing 20 can adjust the axial relative position to each other.

According to an embodiment of the present application, one end of the liner 20 is open, e.g., the liner 20 is a cup-shaped body. In the assembled state, the inner surface 21 of the sleeve 20 is in contact with the outer surface 51 of the stem prosthesis 50 and is secured. For example, the inner surface 21 of the bushing 20 is tapered, while the outer surface 51 of the stem prosthesis 50 is also tapered. When the bushing 20 is connected to the stem prosthesis 50, the inner surface 21 and the outer surface 51 form a taper self-lock, thereby fixedly coupling the bushing 20 and the stem prosthesis 50. Of course, the liner 20 may be open at both ends and not interfere with the fixation of the liner 20 to the stem prosthesis 50. Alternatively, the sleeve 20 may be fixedly coupled to the stem prosthesis 50 by other fastening means, such as a threaded connection, a snap-fit connection, or the like.

According to an embodiment of the present application, as shown in fig. 1, the inner surface of the recess 15 is provided with an internal thread 12, and the outer surface of the bush 20 is provided with an external thread 22, so that the internal thread 12 is engaged with the external thread 22. By rotating the body 10, the axial relative position of the body 10 and the bush 20 can be adjusted. The distance between the spherical center O of the body 10 and the bone distance of the stem prosthesis 50 is the neck length L. The neck length L varies with rotation of the body 10. When the neck length L of the newly formed joint combination is the same as the physiological neck length, the body 10 and the bush 20 can be fixed at the adjusted position by the fixing member 30. With respect to a detailed description of the fixing member 30, it will be described hereinafter with reference to fig. 3.

Referring to fig. 2, fig. 2 is a schematic cross-sectional view of an articulating head prosthesis assembly according to another exemplary embodiment of the present application. As shown in fig. 2, the joint head prosthesis assembly 100 is assembled with the stem prosthesis 50, but the cup prosthesis 40 is not shown. In the illustrated embodiment, unlike the embodiment shown in fig. 1, the articular head prosthesis assembly 100 includes an elastic member 60, for example, at least one coil spring or leaf spring, in addition to the body 10, the bushing 20, and the fixing member 30. The elastic member 60 is disposed in the recess 15 between the body 10 and the bush 20 to apply a pushing force to the bush 20 and the body 10. In addition, the inner surface 13 of the recess 15 and the outer surface 23 of the bush 20 are cylindrical surfaces, such as cylindrical surfaces, square cylindrical surfaces, etc., so that the body 10 can slide on the bush 20, whereby the axial relative positions of each other can be adjusted. When the joint head prosthesis assembly 100 is implanted in a patient, the neck length L of the newly formed joint combination may be automatically adjusted due to the cooperation of the patient's own soft tissue constraint and the elastic member 60. After the joint combination is stabilized, the body 10 and the bush 20 may be fixed by the fixing member 30.

In the embodiment shown in fig. 1 and 2, the fixing member 30 is a screw, for example, a full-thread socket head cap screw. As shown in fig. 1 and 2, the second end of the body 10 is provided with a projection 16, the projection 16 being provided with at least one threaded through hole 17 opening onto the inner surface 13 of the recess 15, the threaded through hole 17 being adapted to receive at least one fixing element 30. As shown in fig. 3, when the screw is screwed into the through hole 17, the front end of the screw abuts against the outer surface 23 of the bushing 20, so that the body 10 and the bushing 20 can be axially fixed, and the final implantation effect can be achieved. Of course, the fixing member 30 may be other members capable of fixing the body 10 and the bush 20, for example, a pin, a snap, a ratchet, etc. In fig. 1 and 2, only two fixing members 30 are shown, but it should be understood that the number of fixing members 30 may be selected according to actual needs.

The components of the articulating head prosthesis assembly of the present application may be made of cobalt chromium molybdenum alloys, but may also be made of conventional titanium alloys or suitable materials developed in the future.

The application of the articulating head prosthesis assembly of the present application is described below with respect to femoral head prosthesis assemblies. When hip joint replacement is carried out, firstly, femoral head prosthesis components with matched specifications are selected according to the size of a joint socket, bone and pathological change conditions. Then, the first end of the body of the femoral head prosthesis component is placed into the ball socket of the acetabular cup prosthesis, so that the spherical surface of the first end of the body and the inner surface of the ball socket of the acetabular cup prosthesis form a spherical hinge structure. Thereafter, the liner sleeve of the femoral head prosthesis assembly is assembled with the femoral stem prosthesis such that the inner surface of the liner sleeve forms a taper self-lock with the outer surface of the femoral stem prosthesis. Then, the fixing member is released, and the neck length L is adjusted or automatically adapted by sliding or rotating the body. When the neck length L is consistent with the physiological neck length, the fixing part is adjusted to axially fix the body and the lining, so that the final implantation effect is realized.

By utilizing the joint head prosthesis component, the consistency of the neck length and the physiological neck length of the newly formed joint combination can be ensured by adjusting the length of the joint head prosthesis component or automatically adapting to the physiological neck length, so that the risks of dislocation of the joint prosthesis, pain of a patient and the like caused by the inconsistency of the physiological neck length and the prosthesis neck length are eliminated, and the operation quality is further improved.

The present application is described in detail above with reference to specific embodiments. It is to be understood that both the foregoing description and the embodiments shown in the drawings are to be considered exemplary and not restrictive of the application. For example, the present application has been described in the preferred embodiment with respect to femoral head prosthesis components for hip replacement, but the present application is equally applicable to joint head prosthesis components for shoulder or other joints. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit of the application, and these changes and modifications do not depart from the scope of the application.

Claims

1. An articular head prosthesis assembly, the articular head prosthesis assembly (100) comprising:

a body (10), the body (10) comprising a first end and a second end extending in an axial direction, the outer surface (11) of the first end being spherical and the second end being provided with a recess (15);

characterized in that said joint head prosthesis assembly (100) further comprises:

a bushing (20), at least a portion of said bushing (20) being configured to be movably received within said recess (15) such that said body (10) and said bushing (20) are adjustable in axial relative position to each other; and

a fixing part (30), the fixing part (30) being configured to fix or release the body (10) and the bush (20).

2. The articular head prosthesis assembly according to claim 1, characterized in that the inner surface (13) of the recess (15) is provided with an internal thread (12) and the outer surface (23) of the bushing (20) is provided with an external thread (22), so that the body (10) can be rotated with respect to the bushing (20) to adjust the axial relative position.

3. The articular head prosthesis assembly according to claim 1, characterized in that the inner surface (13) of the recess (15) is cylindrical and the outer surface (23) of the bush (20) is cylindrical, so that the body (10) can slide with respect to the bush (20) to adjust the axial relative position.

4. The articular head prosthesis assembly according to claim 3, characterized in that the articular head prosthesis assembly (100) further comprises an elastic element (60), the elastic element (60) being arranged within the recess (15) between the body (10) and the bushing (20).

5. The articular head prosthesis assembly according to claim 1, characterized in that at least one end of the bushing (20) is open and the inner surface (21) of the bushing (20) is conical.

6. The articular head prosthesis assembly according to claim 1, characterized in that the fixation means (30) is at least one screw and the second end of the body (10) is provided with a projection (16), said projection (16) being provided with at least one threaded through hole (17) for receiving the fixation means (30).

7. The articulating head prosthesis assembly of claim 6, wherein said screw is a full thread socket head cap screw.

8. The articular head prosthesis assembly according to claim 4, characterized in that the elastic element (60) is at least one helical spring or leaf spring.

9. The articular head prosthesis assembly according to claim 1, characterized in that the articular head prosthesis assembly (100) is a femoral head prosthesis assembly for hip arthroplasty.

10. An artificial joint, characterized in that it comprises a joint head prosthesis assembly (100) according to any one of claims 1-9.