Articular head prosthesis component

Abstract

The present application provides a joint head prosthesis assembly, and the joint head prosthesis assembly includes: a body, the body includes a first end and a second end extending along an axis, an outer surface of the first end is a spherical surface, and a recessed portion is provided at the second end; wherein, the joint head prosthesis assembly further includes: a bushing, at least a part of the bushing is configured to be received in the recessed portion, so that the body and the bushing can adjust their axial relative positions with respect to each other; and a fixing member, the fixing member is configured to fix or release the body and the bushing. The present application also relates to an artificial joint including the above joint head prosthesis assembly. By adjusting the self-length of the joint head prosthesis assembly or automatically adapting to the physiological neck length, the present application can ensure that the neck length of the newly formed joint combination is consistent with the physiological neck length, thereby eliminating risks such as joint prosthesis dislocation and patient pain caused by the inconsistency, and further improving the surgical quality.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to a joint head prosthesis component for artificial joint replacement. Background Art

[0002] For severe joint diseases, when conservative treatment is ineffective or the effect is not significant, the most effective treatment method is joint replacement surgery. By using artificial prosthesis components to replace the diseased local joint or the entire joint, joint pain can be effectively relieved, joint stability can be maintained, joint function can be improved, etc. The complexity of joint replacement surgery requires that the prosthesis components must not only have good material properties, such as biocompatibility, corrosion resistance, high strength, etc., but also have good combined mechanical properties, structural matching, etc., to avoid phenomena such as stress concentration and unbalanced stress distribution after the prosthesis is implanted into the living body, which will damage the normal joint biomechanical distribution law, and then cause a series of complications such as postoperative bone resorption, bone atrophy, and prosthesis loosening.

[0003] Taking hip replacement surgery as an example, the femoral head prosthesis component used clinically is a surgical implant for the femoral head part of the human hip joint. Its shape is mostly spherical, and the material is mostly made of biocompatible titanium alloy or cobalt-chromium-molybdenum alloy. In total hip replacement surgery, the femoral head prosthesis component is tapered with the femoral stem prosthesis on the femoral side and cooperates with the acetabular cup prosthesis on the acetabular side to form a ball joint structure to replace the diseased femoral head or the 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 calcar is called the neck length. The neck length of the newly formed joint combination should be consistent with the physiological neck length. However, in actual applications, the length of the femoral head prosthesis component itself is fixed, and due to the complex human body structure, the neck length of the newly formed joint combination after replacement may not necessarily be guaranteed to be exactly the same as the physiological neck length. If the neck length of the newly formed joint combination is too small, the femoral head prosthesis component is prone to dislocation. On the contrary, if the neck length of the newly formed joint combination is too large, it may cause postoperative pain and trouble the patient's postoperative life.

[0004] For the shoulder joint or other bone joints with an articular socket, similar problems also exist during the replacement process of the joint head prosthesis component.

[0005] Therefore, a joint head prosthesis component that can adjust its own length and adapt to the physiological neck length is needed. Summary of the Invention

[0006] The purpose of this application is to overcome at least one defect existing in the prior art, and propose a joint head prosthesis component for artificial joint replacement. This joint head prosthesis component can adjust its own length by using a simple structure, so as to adapt to the physiological neck length and improve the surgical quality.

[0007] To this end, according to one aspect of the present application, a joint head prosthesis assembly is provided. The joint head prosthesis assembly includes: a body, the body includes a first end and a second end extending along an axis, the outer surface of the first end is a spherical surface, and the second end is provided with a recess; wherein, the joint head prosthesis assembly further includes: a bushing, at least a part of the bushing is configured to be movably received in the recess, so that the body and the bushing can adjust their axial relative positions; and a fixing member, the fixing member is configured to fix or release the body and the bushing.

[0008] 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, so that the body can rotate relative to the bushing to adjust the axial relative position.

[0009] Preferably, the inner surface of the recess is a cylindrical surface, and the outer surface of the bushing is a cylindrical surface, so that the body can slide relative to the bushing to adjust the axial relative position.

[0010] Preferably, the joint head prosthesis assembly further includes an elastic member, and the elastic member is arranged in the recess and between the body and the bushing.

[0011] Preferably, at least one end of the bushing is open, and the inner surface of the bushing is a conical surface.

[0012] Preferably, the fixing member is at least one screw, and the second end of the body is provided with a protruding portion, and the protruding portion is provided with at least one threaded through hole for receiving the fixing member.

[0013] Preferably, the screw is a fully threaded hexagon socket screw.

[0014] Preferably, the elastic member is at least one helical spring or leaf spring.

[0015] Preferably, the joint head prosthesis assembly is a femoral head prosthesis assembly for hip replacement surgery.

[0016] According to another aspect of the present application, an artificial joint is provided, including the joint head prosthesis assembly as described above.

[0017] According to the present application, the joint head prosthesis assembly includes a body and a bushing that can adjust their axial relative positions, and thus can adjust the self-length of the joint head prosthesis assembly to ensure that the neck length of the newly formed joint combination is consistent with the physiological neck length to achieve the final implantation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings and the present application will be further explained. In the drawings:

[0019] Figure 1 FIG. 2 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 an acetabular cup prosthesis and a bone stem prosthesis;

[0020] Figure 2 FIG. 3 is a schematic cross-sectional view of a joint head prosthesis assembly according to another exemplary embodiment of the present application, wherein the joint head prosthesis assembly is assembled with a bone stem prosthesis;

[0021] Figure 3 is Figure 1 and 2 FIG. 4 is a partially enlarged cross-sectional view of the joint head prosthesis assembly shown in FIGS. 2 and 3, wherein a fixing member is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings and examples.

[0023] In the drawings, for simplicity, other components are omitted, but this does not mean that the joint head prosthesis assembly of the present application cannot include other components. Additionally, it should be understood that the drawings are only used for exemplary illustration of the present application, and the dimensions, proportional relationships, and the number of components thereof do not limit the present application. In different drawings, the same or similar components are denoted by the same reference numerals.

[0024] In the preferred embodiments of the present application, the femoral head prosthesis assembly for artificial hip joint replacement is taken as an example to describe the present application. However, those skilled in the art should understand that these exemplary embodiments do not impose any limitation on the present application. For example, the prosthesis of the present application can be used as the joint head prosthesis assembly of other artificial joints with an articular socket, such as the shoulder joint. In addition, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0025] First, refer to Figure 1 , Figure 1 FIG. 2 is a schematic cross-sectional view of a joint head prosthesis assembly according to an exemplary embodiment of the present application. As shown in FIG. 2, the joint head prosthesis assembly of the present application is assembled with an acetabular cup prosthesis 40 and a bone stem prosthesis 50. The joint head prosthesis assembly includes a body 10, a bushing 20, and a fixing member 30. The spherical outer surface of the body 10 cooperates with the spherical socket inner surface of the acetabular cup prosthesis 40 to form a ball joint structure, and the bushing 20 is fixedly connected to the bone stem prosthesis 50. The body 10 and the bushing 20 can adjust their axial relative positions with respect to each other and are fixed in the adjusted positions by the fixing member 30. Figure 1

[0026] ​According to an embodiment of the present application, the body 10 includes a first end and a second end extending axially, where the axial direction refers to the long axis direction of the femoral head prosthesis assembly. The outer surface 11 of the first end of the body 10 is spherical to cooperate with the inner surface of the spherical socket of the acetabular cup prosthesis 40 to form a ball joint structure. A recess 15 is provided at the second end of the body 10, and the recess 15 is configured to movably receive at least a part of the bushing 20, so that the body 10 and the bushing 20 can adjust their axial relative positions with respect to each other.

[0027] According to an embodiment of the present application, one end of the bushing 20 is open. For example, the bushing 20 is a cup-shaped body. In the assembled state, the inner surface 21 of the bushing 20 contacts and is fixed to the outer surface 51 of the bone stem prosthesis 50. For example, the inner surface 21 of the bushing 20 is a conical surface, and the outer surface 51 of the bone stem prosthesis 50 is also a conical surface. When the bushing 20 is connected to the bone stem prosthesis 50, the inner surface 21 and the outer surface 51 form a taper self-locking, thereby fixedly connecting the bushing 20 and the bone stem prosthesis 50. Of course, the bushing 20 can also be open at both ends, and it does not affect the fixation of the bushing 20 and the bone stem prosthesis 50. In addition, the bushing 20 can also be fixedly connected to the bone stem prosthesis 50 by other fixing methods, such as screw connection, snap connection, etc.

[0028] According to an embodiment of the present application, as Figure 1 shown, an internal thread 12 is provided on the inner surface of the recess 15, and an external thread 22 is provided on the outer surface of the bushing 20. In this way, the internal thread 12 cooperates with the external thread 22. By rotating the body 10, the axial relative position between the body 10 and the bushing 20 can be adjusted. The distance between the center of the ball O of the body 10 and the bone offset of the bone stem prosthesis 50 is the neck length L. The neck length L changes with the 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 bushing 20 can be fixed at the adjusted position by the fixing member 30. A detailed description of the fixing member 30 will be described below with reference to Figure 3 is described.

[0029] Referring to Figure 2 , Figure 2 is a schematic cross-sectional view of a femoral head prosthesis assembly according to another exemplary embodiment of the present application. As Figure 2 shown, the femoral head prosthesis assembly 100 is assembled with the bone stem prosthesis 50, but the acetabular cup prosthesis 40 is not shown. In the illustrated embodiment, compared with Figure 1Different from the embodiments shown, the articular head prosthesis assembly 100 further includes an elastic member 60 in addition to the body 10, the bushing 20, and the fixing member 30. For example, at least one helical spring or leaf spring. The elastic member 60 is disposed within the recess 15 and between the body 10 and the bushing 20 to apply a thrust force to the bushing 20 and the body 10. Additionally, the inner surface 13 of the recess 15 and the outer surface 23 of the bushing 20 are both cylindrical surfaces, such as a cylindrical surface, a square cylindrical surface, etc., such that the body 10 can slide on the bushing 20, thereby allowing adjustment of their relative axial positions. When the articular head prosthesis assembly 100 is implanted into a patient's body, due to the combined action of the patient's own soft tissue constraints and the elastic member 60, the neck length L of the newly formed joint combination can be automatically adjusted. After the joint combination stabilizes, the body 10 and the bushing 20 can be fixed by the fixing member 30.

[0030] In Figure 1 and 2 the embodiments shown, the fixing member 30 is a screw, for example, a fully threaded hexagon socket screw. As Figure 1 and 2 shown, the second end of the body 10 is provided with a protrusion 16, and the protrusion 16 is provided with at least one threaded through hole 17 leading to the inner surface 13 of the recess 15, and the threaded through hole 17 is used to receive at least one fixing member 30. As Figure 3 shown, 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, then the body 10 and the bushing 20 can be axially fixed, thereby achieving the final implantation effect. Of course, the fixing member 30 can also be other components capable of fixing the body 10 and the bushing 20, such as pins, snaps, ratchets, etc. In Figure 1 and 2 only two fixing members 30 are shown, but it should be understood that the number of fixing members 30 can be selected according to actual needs.

[0031] Each component of the articular head prosthesis assembly of the present application can be made of cobalt-chromium-molybdenum alloy. Of course, it can also be made of common titanium alloy or appropriate materials developed in the future.

[0032] The application of the articular head prosthesis component of the present application will be described below by taking the femoral head prosthesis component as an example. During hip replacement surgery, first, a femoral head prosthesis component with a matching specification is selected according to the size, bone quality, and lesion condition of the acetabulum. 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 forms a ball hinge structure with the inner surface of the ball socket of the cup prosthesis. After that, the bushing of the femoral head prosthesis component and the femoral stem prosthesis are assembled, so that the inner surface of the bushing forms a taper self-locking with the outer surface of the femoral stem prosthesis. Then, the fixing component is loosened, and the neck length L is adjusted by sliding or rotating the body or automatically adapting to the neck length L. When the neck length L is consistent with the physiological neck length, the fixing component is adjusted to axially fix the body and the bushing, thereby achieving the final implantation effect.

[0033] By using the articular head prosthesis component of the present application, by adjusting the self-length of the articular head prosthesis component or automatically adapting to the physiological neck length, the consistency between the neck length of the newly formed joint combination and the physiological neck length can be ensured, thereby eliminating risks such as joint prosthesis dislocation and patient pain caused by the inconsistency between the physiological neck length and the prosthesis neck length, and further improving the surgical quality.

[0034] The present application has been described in detail above in combination with specific embodiments. Obviously, the above description and the embodiments shown in the drawings should be understood as exemplary and do not constitute a limitation to the present application. For example, in the preferred embodiment, the present application is described by taking the femoral head prosthesis component for hip replacement as an example. However, for the articular head prosthesis component for shoulder joint or other joints, the articular head prosthesis component of the present application is equally applicable. For those skilled in the art, various variations or modifications can be made to it without departing from the spirit of the present application, and these variations or modifications do not depart from the scope of the present application.

Claims

1. An articular head prosthesis component for hip replacement surgery, said articular head prosthesis component (100) comprising: a body (10), the body (10) including a first end and a second end extending axially, an outer surface (11) of the first end being spherical, the spherical surface being configured to cooperate with an inner surface of a spherical socket of an acetabular cup prosthesis (40) to form a ball joint structure, and a recessed portion (15) being provided at the second end; characterized in that, the articular head prosthesis component (100) further comprises: a bushing (20), an inner surface (21) of the bushing (20) being configured to contact and be fixed to an outer surface (51) of a femoral stem prosthesis (50), at least a part of the bushing (20) being configured to be movably received within the recessed portion (15) such that the body (10) and the bushing (20) can adjust their axial relative positions; and a fixing member (30), the fixing member (30) being configured to fix the body (10) and the bushing (20) in the adjusted position when a distance between the center of the ball (O) of the body (10) and the femoral neck of the femoral stem prosthesis (50) is the same as the physiological neck length, so as to ensure that the neck length of the newly formed hip joint combination is consistent with the physiological neck length, wherein the fixing member (30) is at least one screw; wherein, an inner surface (13) of the recessed portion (15) is a cylindrical surface, and an outer surface (23) of the bushing (20) is a cylindrical surface, such that the body (10) can slide relative to the bushing (20) to adjust the axial relative position; wherein, the articular head prosthesis component (100) further comprises an elastic member (60), the elastic member (60) being disposed within the recessed portion (15) and between the body (10) and the bushing (20) to apply a thrust force to the bushing (20) and the body (10).

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

3. The articular head prosthesis component according to claim 1, characterized in that, a protruding portion (16) is provided at the second end of the body (10), and at least one threaded through hole (17) for receiving the fixing member (30) is provided in the protruding portion (16).

4. The articular head prosthesis component according to claim 3, characterized in that, the screw is a fully threaded hexagon socket head screw.

5. The articular head prosthesis component according to claim 1, characterized in that, the elastic member (60) is at least one helical spring or leaf spring.

6. An artificial joint, comprising the articular head prosthesis component (100) according to any one of claims 1-5.

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