Wrist Prosthesis

Abstract

The present invention provides a wrist joint prosthesis, mainly comprising: a first joint handle assembly, the first joint handle assembly is used to connect with the radius, the first joint handle assembly includes a first locking part, the first locking part has a locking state and an insertion state; a locking shaft, the locking shaft has an expansion part, the locking shaft is movably arranged relative to the first joint handle assembly, so that the expansion part pushes the first locking part to adjust from the insertion state to the locking state; wherein the radius has a medullary cavity, the first joint handle assembly is inserted into the medullary cavity of the radius through the first locking part, so that when the first locking part is in the locking state, the first locking part abuts against the inner wall of the medullary cavity to lock the first joint handle assembly on the radius; and when the first locking part is in the insertion state, the first locking part is separated from the inner wall of the medullary cavity, so that the first joint handle assembly is movably arranged relative to the radius. The wrist joint prosthesis of the present invention solves the problem of easy loosening of the prosthesis after total wrist replacement in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of prostheses, and in particular to a wrist joint prosthesis. Background Art

[0002] The wrist joint, also known as the radiocarpal joint, is a typical elliptical joint, consisting of the proximal articular surfaces of the scaphoid, lunate and triquetrum bones of the hand as the articular head, and the carpal articular surface of the radius and the articular disc below the ulnar head as the articular fossa. The joint capsule is loose, and the front, back and sides of the joint are reinforced by ligaments, among which the palmar ligament is the toughest, so the wrist extension movement is limited.

[0003] The radiocarpal joint can perform flexion, extension, abduction, adduction and circumduction. The wrist joint is the most complex joint in the human body. Many diseases or traumas can cause chronic pain and loss of function in the wrist joint, such as rheumatoid arthritis, traumatic arthritis, osteoarthritis, suppurative arthritis, tumors of the wrist joint, etc.

[0004] Artificial total wrist prosthesis is mainly used for patients with wrist pain, deformity, and loss of function caused by various traumas, autoimmune diseases, and degenerative changes. Especially for patients with joint lesions involving multiple joints, it can restore most of the functions of the wrist joint, reduce the disability rate, and improve the quality of life of patients. The wrist joint is a very flexible and most complex joint in the human body, and it plays the greatest role in daily life. Immune diseases such as rheumatoid arthritis often accumulate in the wrist joint, and degenerative lesions caused by trauma and excessive use in work and life can cause serious damage to the wrist joint. The current common total wrist fusion technology will cause patients to lose almost all wrist function, especially for patients with lesions accumulated in multiple joints. The function loss rate is higher. Total wrist replacement can retain most of the functions of the wrist joint and completely solve the patient's pain and deformity problems.

[0005] However, the total wrist replacement prosthesis in the prior art is easy to loosen, unstable and has a high probability of breaking. Since the first generation of artificial total wrist joints have been used for more than half a century, the stability and durability of artificial joints have always been the main factors restricting their development. Summary of the invention

[0006] The main purpose of the present invention is to provide a wrist joint prosthesis to solve the problem of easy loosening of the prosthesis after total wrist joint replacement in the prior art.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a wrist joint prosthesis for connecting the radius and the metacarpal bone, the wrist joint prosthesis comprising: a first joint handle assembly, the first joint handle assembly is used to connect to the radius, the first joint handle assembly comprises a first locking portion, the first locking portion has a locking state and an inserted state; a locking shaft, the locking shaft has an expansion portion, the locking shaft is movably arranged relative to the first joint handle assembly, so that the expansion portion pushes the first locking portion to adjust from the inserted state to the locking state; wherein, the radius has a medullary cavity, the first joint handle assembly is inserted into the medullary cavity through the first locking portion, so that when the first locking portion is in the locking state, the first locking portion abuts against the inner wall of the medullary cavity, so as to lock the first joint handle assembly on the radius; and when the first locking portion is in the inserted state, the first locking portion is separated from the inner wall of the medullary cavity, so that the first joint handle assembly is movably arranged relative to the radius.

[0008] Furthermore, the first locking portion is a circular tube structure, and a plurality of first cutouts are provided on the circular tube structure. The plurality of first cutouts are arranged at intervals along the circumference of the circular tube structure, and each first cutout extends along the axial direction of the circular tube structure; the locking shaft is movably inserted in the hole of the circular tube structure, so that when the expansion portion moves to the inner side of the first cutout, the first locking portion is stretched outward, so that the first locking portion is adjusted from the inserted state to the locked state.

[0009] Furthermore, the expansion portion is a conical structure, and the diameter of the base of the conical structure is larger than the inner diameter of the first locking portion, so that when the expansion portion passes through the hole on the first locking portion, the first locking portion is pushed outward.

[0010] Furthermore, the wrist joint prosthesis also includes: a second joint handle assembly, the second joint handle assembly is rotatably connected to the first joint handle assembly, the second joint handle assembly includes an inserting portion, the inserting portion is used to be inserted on the metacarpal bone to connect the second joint handle assembly to the metacarpal bone.

[0011] Furthermore, the wrist joint prosthesis also includes: a connecting joint, which is connected to the first joint handle assembly, and a connecting joint surface is provided on the connecting joint. The second joint handle assembly includes a rotating part, and the second joint handle assembly is rotatably arranged in the connecting joint surface through the rotating part.

[0012] Furthermore, the rotating part is provided with a plurality of positioning pins, the plug-in part is provided with a plurality of positioning holes, the plurality of positioning pins are arranged in one-to-one correspondence with the plurality of positioning holes, and the rotating part is inserted into the corresponding positioning holes through the positioning pins to be connected with the plug-in part.

[0013] Furthermore, a second locking portion is provided on the positioning pin, and after the positioning pin is inserted into the positioning hole, the second locking portion is used to lock the positioning pin in the positioning hole.

[0014] Furthermore, the second locking portion includes a limiting protrusion, which is arranged at an end of the positioning pin away from the rotating portion, so that after the positioning pin is inserted into the positioning hole, the limiting protrusion passes through the positioning hole and limits the positioning pin in the positioning hole.

[0015] Furthermore, a plurality of second cutouts are provided on the positioning pin, and the plurality of second cutouts are arranged at intervals along the circumference of the positioning pin, and each second cutout is extended along the axial direction of the positioning pin.

[0016] Furthermore, a first connecting hole is provided on the connecting joint, a first connecting portion is provided on the locking shaft, and the locking shaft is inserted into the first connecting hole through the first connecting portion to be connected to the connecting joint.

[0017] Furthermore, the first connecting hole is provided with an internal thread, the first connecting portion is provided with an external thread matching the internal thread, and the first connecting portion and the first connecting hole are connected through the thread matching between the internal thread and the external thread.

[0018] Furthermore, locking holes are provided on the connecting joint and / or the first joint handle assembly, and the wrist joint prosthesis also includes a locking screw, which is movably inserted in the locking hole so that when the locking shaft is inserted into the first connecting hole, the locking screw abuts against the locking shaft to fix the locking shaft in the first connecting hole.

[0019] Furthermore, the plug-in portion includes: a tray assembly, the tray assembly is connected to the rotating portion; and a plug-in handle, the plug-in handle is arranged on the tray assembly for connecting with the third metacarpal bone on the metacarpal bone.

[0020] Furthermore, the plug-in portion also includes: a plurality of plug-in components, which are arranged at intervals on both sides of the plug-in handle, and the plug-in components are detachably connected to the tray component to fix the second joint handle component on the metacarpal bone together with the plug-in handle.

[0021] Furthermore, the tray component is provided with a plurality of screw holes, and the plurality of plug-in components are arranged in one-to-one correspondence with the plurality of screw holes, and at least a portion of the plug-in components is provided with external threads so that the plug-in components are matched and connected with the corresponding screw holes.

[0022] Furthermore, the plug-in component is a screw, and the included angles between at least some of the multiple plug-in components and the tray component are different.

[0023] Furthermore, the connecting joint has a first mounting surface and a second mounting surface arranged opposite to each other, and the connecting joint also has a first end and a second end arranged opposite to each other, the first joint handle assembly is arranged on the first mounting surface close to the first end, and the second joint handle assembly is arranged on the second mounting surface close to the second end.

[0024] The wrist joint prosthesis using the technical solution of the present invention is used to connect the radius and the metacarpal bone of the metacarpal bone. The wrist joint prosthesis includes: a first joint handle component, a first locking part is provided at one end of the first joint handle component, and the first locking part has two states: a locking state for locking the first joint handle component and the radius and an inserted state that enables the first joint handle component to move relative to the radius. The wrist joint prosthesis also includes a locking shaft, a through hole is provided in the middle of the first joint handle component, and the locking shaft is used to be inserted into the through hole inside the first joint handle component. An expansion part is provided at the end of the locking shaft opposite to the first locking part, and the expansion part is movably arranged relative to the first locking part. When in use, the first joint handle component is arranged in the medullary cavity of the radius, and one end of the first locking part is located inside the medullary cavity. The locking shaft is pulled so that the expansion part cooperates with the first locking part to switch the first locking part to the locking state. When the first locking part is in the locking state, the first locking part abuts against the inner side of the medullary cavity, thereby fixing the first joint handle component to the radius. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 A schematic diagram showing a first perspective of an embodiment of a wrist joint prosthesis according to the present invention;

[0027] Figure 2 A schematic diagram showing a second perspective of an embodiment of a wrist joint prosthesis of the present invention;

[0028] Figure 3 A cross-sectional view of a first joint handle assembly, a locking shaft and a connecting joint connection embodiment of a wrist joint prosthesis of the present invention is shown;

[0029] Figure 4 An assembly diagram showing a first joint handle component, a locking shaft and a connecting joint connection embodiment of a wrist joint prosthesis of the present invention is shown;

[0030] Figure 5 A schematic diagram showing an embodiment of a second joint handle component of a wrist joint prosthesis of the present invention;

[0031] Figure 6 A cross-sectional view showing an embodiment of a second stem component of a wrist joint prosthesis of the present invention.

[0032] The above drawings include the following reference numerals:

[0033] 10. First joint handle assembly; 11. First locking portion; 111. First incision; 12. Positioning portion; 20. Locking shaft; 21. Expansion portion; 22. First connecting portion; 30. Second joint handle assembly; 31. Plug-in portion; 311. Positioning hole; 32. Rotating portion; 321. Positioning pin; 322. Second locking portion; 323. Second incision; 33. Tray assembly; 331. Screw hole; 34. Plug-in assembly; 35. Plug-in handle; 40. Connecting joint; 401. First mounting surface; 402. Second mounting surface; 403. First end; 404. Second end; 41. Connecting joint surface; 42. First connecting hole; 43. Locking hole. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] The present invention provides a wrist joint prosthesis for connecting the radius and the metacarpal bone, please refer to Figures 1 to 6 The wrist joint prosthesis includes: a first joint handle component 10, the first joint handle component 10 is used to be connected to the radius, the first joint handle component 10 includes a first locking portion 11, the first locking portion 11 has a locking state and an insertion state; a locking shaft 20, the locking shaft 20 has an expansion portion 21, the locking shaft 20 is movably arranged relative to the first joint handle component 10, so that the expansion portion 21 pushes the first locking portion 11 to adjust from the insertion state to the locking state; wherein, the radius has a medullary cavity, and the first joint handle component 10 is inserted into the medullary cavity through the first locking portion 11, so that when the first locking portion 11 is in the locking state, the first locking portion 11 abuts against the inner wall of the medullary cavity to lock the first joint handle component 10 on the radius; and when the first locking portion 11 is in the insertion state, the first locking portion 11 is separated from the inner wall of the medullary cavity, so that the first joint handle component 10 is movably arranged relative to the radius.

[0036] The wrist joint prosthesis of the present invention is used to connect the metacarpal bones of the radius and the metacarpal bones. The wrist joint prosthesis includes: a first joint handle component 10, one end of the first joint handle component 10 is provided with a first locking portion 11, the first locking portion 11 has two states: a locking state for locking the first joint handle component and the radius and an inserted state that enables the first joint handle component 10 to move relative to the radius. The wrist joint prosthesis also includes a locking shaft 20, a through hole is provided in the middle of the first joint handle component 10, and the locking shaft is used to be inserted in the first joint handle component 10. In the through hole inside the joint handle assembly, an expansion portion 21 is provided at the end of the locking shaft opposite to the first locking portion 11, and the expansion portion 21 is movably arranged relative to the first locking portion. When in use, the first joint handle assembly is arranged in the medullary cavity of the radius, and one end of the first locking portion is located inside the medullary cavity. The locking shaft is pulled to make the expansion portion cooperate with the first locking portion to switch the first locking portion to a locking state. When the first locking portion is in the locking state, the first locking portion abuts against the inner side of the medullary cavity, thereby fixing the first joint handle assembly to the radius.

[0037] The first locking portion 11 is a circular tube structure, and a plurality of first cutouts 111 are provided on the circular tube structure, and the plurality of first cutouts 111 are arranged at intervals along the circumference of the circular tube structure, and each first cutout 111 is extended along the axial direction of the circular tube structure; the locking shaft 20 is movably inserted into the hole of the circular tube structure, so that when the expansion portion 21 moves to the inner side of the first cutout 111, the first locking portion 11 is pushed outward, so that the first locking portion 11 is adjusted from the inserted state to the locked state. The expansion portion 21 is a conical structure, and the diameter of the base of the conical structure is larger than the inner diameter of the first locking portion 11, so that when the expansion portion 21 passes through the hole on the first locking portion 11, the first locking portion 11 is pushed outward.

[0038] In this embodiment, the first joint handle assembly is a hollow structure with a hole inside. At least two first incisions 111 are arranged on the first locking portion 11 at intervals along the circumferential direction. The first incision is arranged along the length direction of the radius. The locking shaft 20 is inserted into the first joint handle assembly from one end of the first locking portion 11 until the expansion portion passes through the first locking portion. Since the expansion portion is a conical structure, its size is larger than the inner diameter of the first locking portion 11. Therefore, when the expansion portion passes through the position of the first locking portion, the first locking portion structure can be expanded outward and then abutted against the inner wall of the medullary cavity to be fixed.

[0039] The wrist joint prosthesis also includes: a second joint handle assembly 30, which is rotatably connected to the first joint handle assembly 10, and the second joint handle assembly 30 includes an inserting portion 31, which is used to be inserted on the metacarpal bone to connect the second joint handle assembly 30 to the metacarpal bone.

[0040] The wrist joint prosthesis in this embodiment also includes a second joint handle component 30 for connecting to the metacarpal bone on the metacarpal bone. One end of the second joint handle component is connected to the first joint handle component 10, and the other end is connected to the metacarpal bone through the plug-in portion 31.

[0041] The wrist joint prosthesis also includes: a connecting joint 40, which is connected to the first joint handle assembly 10, and a connecting joint surface 41 is provided on the connecting joint 40. The second joint handle assembly 30 includes a rotating part 32, and the second joint handle assembly 30 is rotatably arranged in the connecting joint surface 41 through the rotating part 32.

[0042] In this embodiment, a connecting joint 40 is provided with a connecting joint surface 41, and a groove is provided on the connecting joint surface 41. The rotating part 32 is arranged in the groove to be rotatably connected with the connecting joint surface. The rotating part 32 is an outward hemispherical protrusion matching the groove at the connecting joint surface. The rotating part 32 is arranged in the connecting joint surface 41 so that the rotating part 32 can be limited in the connecting joint surface 41 for rotation to prevent slipping.

[0043] The rotating part 32 is provided with a plurality of positioning pins 321, and the plug-in part 31 is provided with a plurality of positioning holes 311. The plurality of positioning pins 321 are arranged one-to-one with the plurality of positioning holes 311. The rotating part 32 is inserted into the corresponding positioning holes 311 through the positioning pins 321 to connect with the plug-in part 31. The positioning pin 321 is provided with a second locking part 322. After the positioning pin 321 is inserted into the positioning hole 311, the second locking part 322 is used to lock the positioning pin 321 in the positioning hole 311. The second locking part 322 includes a limiting protrusion, which is arranged at one end of the positioning pin 321 away from the rotating part 32, so that after the positioning pin 321 is inserted into the positioning hole 311, the limiting protrusion passes through the positioning hole 311 and limits the positioning pin 321 in the positioning hole 311. The positioning pin 321 is provided with a plurality of second cutouts 323 . The plurality of second cutouts 323 are arranged at intervals along the circumference of the positioning pin 321 . Each second cutout 323 is extended along the axial direction of the positioning pin 321 .

[0044] like Figure 5 and Figure 6As shown, the second joint handle assembly of the wrist joint prosthesis in this embodiment includes a transfer portion and a plug-in portion. Preferably, a hemispherical protrusion for cooperating with a connecting joint surface is provided at one end of the rotating portion close to the connecting joint 40, and the hemispherical protrusion is arranged in the connecting joint surface, so as to not only play a role of rotational connection, but also reliably connect the second joint handle assembly to the connecting joint to prevent dislocation and disjointment. In addition, the rotating portion in this embodiment is provided with two locating pins, and the two locating pins are respectively arranged at one end of the rotating portion close to the plug-in portion. The plug-in portion 31 includes a tray assembly 33 and a plug-in assembly 34. A locating hole 311 for connecting with the locating pin is provided on the tray assembly. One end of the locating pin is arranged on the rotating portion. A second locking portion 322 is provided on the other end, and the second locking portion is a limiting protrusion, which is a hook structure. At the same time, the positioning pin is a hollow structure, and a plurality of second cutouts 323 are arranged at intervals along the circumference of the second locking portion 322, so that when the rotating portion is combined with the plug-in portion, the positioning pin is arranged corresponding to the position of the positioning hole, and the positioning pin is squeezed and inserted into the positioning hole. At the same time, the limiting protrusion passes through the other end of the positioning hole, and the hook structure prevents the positioning pin from escaping from the positioning hole, thereby ensuring that the rotating portion and the plug-in portion are locked. The plug-in component 34 is preferably a screw, and a screw hole 331 connected to the screw is provided on the tray component. The plug-in component is fixed to the tray component through the screw hole 331, and the extension directions of each screw are different.

[0045] The connecting joint 40 is provided with a first connecting hole 42, and the locking shaft 20 is provided with a first connecting portion 22. The locking shaft 20 is inserted into the first connecting hole 42 through the first connecting portion 22 to connect with the connecting joint 40. The first connecting hole 42 is provided with an internal thread, and the first connecting portion 22 is provided with an external thread matching with the internal thread. The first connecting portion 22 and the first connecting hole 42 are connected by the thread matching between the internal thread and the external thread. The connecting joint 40 and / or the first joint handle assembly 10 are both provided with a locking hole 43. The wrist joint prosthesis also includes a locking screw, which is movably inserted into the locking hole 43, so that when the locking shaft 20 is inserted into the first connecting hole 42, the locking screw abuts against the locking shaft 20 to fix the locking shaft 20 in the first connecting hole 42.

[0046] like Figure 3 and Figure 4As shown, in this embodiment, the connecting joint is an elliptical structure, and a first connecting hole 42 for connecting to a locking shaft is provided on the connecting joint. The locking shaft passes through the middle of the first joint handle assembly, and then the first connecting part 22 is inserted into the first connecting hole 42. Preferably, an outer surface of the first connecting part is provided with an external thread, and an internal thread is provided in the first connecting hole 42. The first connecting part is threadedly connected to the internal thread in the first connecting hole through the external thread, so that the first joint handle assembly is locked on the connecting joint 40. A locking hole 43 is also provided on one side of the connecting joint 40, and the locking hole is connected to the first connecting hole. When the first connecting part is inserted into the first connecting hole, the locking screw passes through the locking hole so that one end of the locking screw abuts against the first connecting part, thereby fixing the locking shaft and the connecting joint together to prevent the locking shaft from rotating out or loosening.

[0047] The plug-in part 31 includes: a tray assembly 33, which is connected to the rotating part 32; and a plug-in handle 35, which is arranged on the tray assembly 33 to be connected to the third metacarpal bone on the metacarpal bone. The plug-in part 31 also includes: a plurality of plug-in assemblies 34, which are arranged at intervals on both sides of the plug-in handle 35, and the plug-in assemblies 34 are detachably connected to the tray assembly 33, so as to fix the second joint handle assembly 30 on the metacarpal bone together with the plug-in handle 35.

[0048] like Figure 2 As shown, preferably, the plug-in part 31 in this embodiment includes a plug-in handle 35 and two plug-in components 34. The plug-in handle passes through the metacarpal bone and is fixed to the third metacarpal bone. The plug-in handle 35 and the tray component 33 are integrally formed. The plug-in component is a screw, one screw is vertically arranged at the center of the tray component, and the other two screws are relatively arranged on both sides of the middle screw. The two screws are inclined relative to the tray component and face different directions respectively, so that the plug-in part is more tightly connected to the metacarpal bone.

[0049] The connecting joint 40 has a first mounting surface 401 and a second mounting surface 402 which are arranged opposite to each other. The connecting joint 40 also has a first end 403 and a second end 404 which are arranged opposite to each other. The first joint handle assembly 10 is arranged on the first mounting surface 401 near the first end 403 , and the second joint handle assembly 30 is arranged on the second mounting surface 402 near the second end 404 .

[0050] The connecting joint 40 has a first mounting surface 401 and a second mounting surface 402 which are arranged opposite to each other. The connecting joint 40 also has a first end 403 and a second end 404 which are arranged opposite to each other. The first joint handle assembly 10 is arranged on the first mounting surface 401 near the first end 403 , and the second joint handle assembly 30 is arranged on the second mounting surface 402 near the second end 404 .

[0051] Preferably, if Figure 2As shown, the first joint handle assembly and the second joint handle assembly in this embodiment are eccentrically arranged, that is, the axis center of the first joint handle assembly and the axis center of the second joint handle assembly are not on the same straight line, the side of the connecting joint has four end faces, the first joint handle assembly and the second joint handle assembly are respectively arranged on both sides of the connecting joint, and are staggered in the extension direction of the first joint handle assembly or the second joint handle assembly, so that the wrist joint prosthesis is more matched with the joint structure of the human wrist.

[0052] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0053] The purpose of the present invention is to provide a wrist joint prosthesis with stable structure, strong anti-dislocation performance and flexible rotation. The total wrist joint prosthesis includes a modular radial joint handle, a distal radial joint surface, a palmar fixation tray and a palmar joint surface. The modular radial joint handle is composed of a core shaft and a radial joint handle. The modular radial joint handle is connected to the distal radial joint surface through a thread; a plug-in handle 35 and a screw hole are arranged below the palmar fixation tray, and the screw direction points to the plug-in handle. The palmar joint surface is located below the distal radial joint surface, and the palmar joint surface covers the surface of the palmar fixation tray. The palmar joint surface and the distal radial joint surface are movably connected.

[0054] To achieve the above object, a specific technical solution of a total wrist joint prosthesis of the present invention is:

[0055] The first joint handle assembly in the present application is a modular radial joint handle, which adopts a modular structure. The locking shaft is a core shaft, which passes through the middle hole of the radial joint handle. The head end of the core shaft adopts a wedge-shaped slope, and the protruding end of the core shaft is a threaded structure.

[0056] The cross-section of the entire handle of the radial joint stem is an elliptical structure to prevent the prosthesis from rotating; the distal part of the handle body inserted into the medullary cavity has several incisions, and an oblique cone design is adopted at the joint end face of the positioning part 12 connected to the joint, which ensures that the prosthesis is firmly fixed on the one hand, and prevents the prosthesis from rotating on the other hand.

[0057] The first joint handle component is a modular radial joint handle. The first joint handle component and the second joint handle component are eccentrically designed from the side, which conforms to the anatomical structure characteristics of the human body.

[0058] The modular radial joint handle is connected to the connecting joint through a core shaft and a thread. During the tightening process, the core shaft is pulled outward, and the taper of the core shaft end is pulled into the middle hole of the connecting joint. The radial joint handle is inserted into the distal medullary cavity and expanded to ensure that the distal end is firmly fixed.

[0059] The connecting joint and the mandrel are fixed by threaded connection and locked on the connecting joint by locking pins to prevent relative movement between the two;

[0060] The rotating part is an ultra-high cross-linked polyethylene pad, whose upper surface is a raised semi-ellipsoidal slideway contact surface, the protrusion on the lower surface is used for assembly with the tray assembly, and the lower surface is provided with two positioning pins for fixing with the tray assembly, and the positioning pins are lugs.

[0061] The tray assembly is elliptical in shape, the plug-in assembly passes through the capitate bone to connect the third metacarpal bone, the left and right two screw holes, and the two outermost holes are connected and fixed to the rotating part.

[0062] There is a lug on the outer side of the lower surface of the rotating part. The lug is provided with a second cutout, i.e., an open groove. The material of the lug is a low elastic modulus material. When installing, the lug is inserted into the positioning hole and is squeezed and deformed. When the installation position is reached, the hook structure design at the end of the lug firmly fixes it on the tray assembly.

[0063] The core shaft passes through the middle hole of the radial joint handle to form a radial joint handle, and the first joint handle component is connected to the connecting joint by a thread. During the tightening process, the taper of the core shaft end is pulled into the middle hole of the first joint handle component, and the first joint handle component is inserted into the distal medullary cavity and expanded; a locking hole is opened on the outside of the connecting joint to prevent relative movement between the first joint handle component and the connecting joint; the tray component is fixed to the third metacarpal bone through the plug-in part, and is fixed with the aid of bone screws on both sides; it is fixed to the tray assembly by the two lugs of the rotating part; the second joint handle component and the connecting joint are movably connected.

[0064] The upper surface of the rotating part is a raised semi-ellipsoidal slideway contact surface, the lower surface is an ultra-high cross-linked polyethylene pad for assembling with the tray assembly, and the lower surface is provided with a lug for fixing with the tray assembly.

[0065] The surface of the tray component is elliptical in shape. The tray component and the modular radial joint handle are both made of titanium alloy material, and the material of the connecting joint is cobalt-chromium-molybdenum alloy.

[0066] Beneficial effects brought by the technical solution of the present invention:

[0067] (1) The present invention provides a total wrist joint prosthesis, which can maintain the anatomical structure of a normal wrist joint, and is closer to a normal wrist joint in function and has more reasonable biomechanics.

[0068] (2) The first joint handle assembly of the present invention adopts a modular structure, in which the proximal end of the elliptical taper close to the connecting joint is fixed, and the distal end of the first joint handle assembly is expanded and fixed, so that the installation of the prosthesis is more stable and the risk of the prosthesis loosening is reduced.

[0069] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0070] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0071] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0072] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0073] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wrist joint prosthesis for connecting the radius and metacarpal bone, characterized in that: The wrist joint prosthesis comprises: A first joint handle assembly (10), the first joint handle assembly (10) being used to be connected to the radius, the first joint handle assembly (10) comprising a first locking portion (11), the first locking portion (11) having a locking state and an inserted state; A locking shaft (20), wherein the locking shaft (20) has an expansion portion (21), and the locking shaft (20) is movably arranged relative to the first joint handle assembly (10), so that the expansion portion (21) pushes the first locking portion (11) to adjust from the inserted state to the locked state; The radius has a medullary cavity, and the first joint handle assembly (10) is inserted into the medullary cavity through the first locking portion (11), so that when the first locking portion (11) is in the locked state, the first locking portion (11) abuts against the inner wall of the medullary cavity to lock the first joint handle assembly (10) on the radius; and when the first locking portion (11) is in the inserted state, the first locking portion (11) is separated from the inner wall of the medullary cavity to enable the first joint handle assembly (10) to be movably arranged relative to the radius; The first locking portion (11) is a circular tube structure, and a plurality of first cutouts (111) are provided on the circular tube structure. The plurality of first cutouts (111) are arranged at intervals along the circumference of the circular tube structure, and each of the first cutouts (111) is extended along the axial direction of the circular tube structure; the locking shaft (20) is movably inserted into the hole of the circular tube structure, so that when the expansion portion (21) moves to the inner side of the first cutout (111), the first locking portion (11) is stretched outward, so that the first locking portion (11) is adjusted from the inserted state to the locked state; The expansion portion (21) is a conical structure, and the diameter of the base of the conical structure is larger than the inner diameter of the first locking portion (11), so that when the expansion portion (21) passes through the hole on the first locking portion (11), the first locking portion (11) is pushed outward; The wrist joint prosthesis also includes a second joint handle assembly (30), which is rotatably connected to the first joint handle assembly (10), and the second joint handle assembly (30) includes an insert portion (31), which is used to be inserted into the metacarpal bone to connect the second joint handle assembly (30) to the metacarpal bone.

2. The wrist joint prosthesis according to claim 1, characterized in that: The wrist joint prosthesis also includes: A connecting joint (40), wherein the connecting joint (40) is connected to the first joint handle assembly (10), and a connecting joint surface (41) is provided on the connecting joint (40), and the second joint handle assembly (30) includes a rotating portion (32), and the second joint handle assembly (30) is rotatably arranged in the connecting joint surface (41) through the rotating portion (32).

3. The wrist joint prosthesis according to claim 2, characterized in that: The rotating part (32) is provided with a plurality of positioning pins (321), and the plug-in part (31) is provided with a plurality of positioning holes (311). The plurality of positioning pins (321) and the plurality of positioning holes (311) are arranged in a one-to-one correspondence, and the rotating part (32) is inserted into the corresponding positioning holes (311) through the positioning pins (321) to be connected with the plug-in part (31).

4. The wrist joint prosthesis according to claim 3, characterized in that: The positioning pin (321) is provided with a second locking portion (322), and after the positioning pin (321) is inserted into the positioning hole (311), the second locking portion (322) is used to lock the positioning pin (321) in the positioning hole (311).

5. The wrist joint prosthesis according to claim 4, characterized in that: The second locking portion (322) comprises a limiting protrusion, which is arranged at an end of the positioning pin (321) away from the rotating portion (32), so that after the positioning pin (321) is inserted into the positioning hole (311), the limiting protrusion passes through the positioning hole (311) and limits the positioning pin (321) in the positioning hole (311).

6. The wrist joint prosthesis according to claim 5, characterized in that: The positioning pin (321) is provided with a plurality of second cutouts (323), the plurality of second cutouts (323) are arranged at intervals along the circumference of the positioning pin (321), and each of the second cutouts (323) is extended along the axial direction of the positioning pin (321).

7. The wrist joint prosthesis according to claim 2, characterized in that: The connecting joint (40) is provided with a first connecting hole (42), the locking shaft (20) is provided with a first connecting portion (22), and the locking shaft (20) is inserted into the first connecting hole (42) through the first connecting portion (22) to be connected to the connecting joint (40).

8. The wrist joint prosthesis according to claim 7, characterized in that: The first connecting hole (42) is provided with an internal thread, the first connecting portion (22) is provided with an external thread matching the internal thread, and the first connecting portion (22) and the first connecting hole (42) are connected by thread matching between the internal thread and the external thread.

9. The wrist joint prosthesis according to claim 7, characterized in that: The connecting joint (40) and / or the first joint handle assembly (10) are both provided with a locking hole (43), and the wrist joint prosthesis also includes a locking screw, which is movably inserted into the locking hole (43) so that when the locking shaft (20) is inserted into the first connecting hole (42), the locking screw abuts against the locking shaft (20) to fix the locking shaft (20) in the first connecting hole (42).

10. The wrist joint prosthesis according to claim 2, characterized in that: The plug-in portion (31) comprises: A tray assembly (33), wherein the tray assembly (33) is connected to the rotating part (32); A plug-in handle (35) is arranged on the tray assembly (33) and is used for connecting with the third metacarpal bone on the metacarpal bone.

11. The wrist joint prosthesis according to claim 10, characterized in that: The plug-in portion (31) further comprises: A plurality of plug-in assemblies (34) are arranged at intervals on both sides of the plug-in handle (35); the plug-in assemblies (34) are detachably connected to the tray assembly (33) so as to fix the second joint handle assembly (30) on the metacarpal bone together with the plug-in handle (35).

12. The wrist joint prosthesis according to claim 11, characterized in that: The tray component (33) is provided with a plurality of screw holes (331), and the plurality of plug-in components (34) are arranged in one-to-one correspondence with the plurality of screw holes (331), and at least a portion of the plug-in components (34) is provided with external threads so that the plug-in components (34) are matched and connected with the corresponding screw holes (331).

13. The wrist joint prosthesis according to claim 11, characterized in that: The plug-in assembly (34) is a screw, and the included angles between at least some of the plug-in assemblies (34) among the plurality of plug-in assemblies (34) and the tray assembly (33) are different.

14. The wrist joint prosthesis according to claim 2, characterized in that: The connecting joint (40) has a first mounting surface (401) and a second mounting surface (402) that are arranged opposite to each other. The connecting joint (40) also has a first end (403) and a second end (404) that are arranged opposite to each other. The first joint handle component (10) is arranged on the first mounting surface (401) at a position close to the first end (403), and the second joint handle component (30) is arranged on the second mounting surface (402) at a position close to the second end (404).

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