Shoulder joint prosthesis

Abstract

The present disclosure relates to a shoulder joint prosthesis, which comprises a glenoid tray (1) and a glenoid head (2), wherein: the glenoid tray (1) has a rod portion (13) and a bottom plate (12) located at one end of the rod portion, and an inner tapered groove (14) is provided in both the rod portion (13) and the bottom plate (12), and the inner tapered groove (14) has an increasing cross-sectional diameter in the direction from the rod portion (13) towards the bottom plate (12), and the bottom plate (12) has a locking portion (11) in the direction opposite to the rod portion; the glenoid head (2) has a head portion (20) and a shank portion (29), at least a part of one end of the shank portion (29) away from the head portion (20) is a tapered structure (21), and the tapered structure (21) can be in taper fit with the inner tapered groove (14), and a locking protrusion (22) is provided on one end of the shank portion (29) close to the head portion (20).

Description

Technical Field

[0001] The present invention relates to a shoulder joint prosthesis, in particular to a shoulder joint prosthesis used in reverse shoulder arthroplasty, which has a glenoid socket and a glenoid head that can be taper-connected, especially Morse taper-connected. Background Art

[0002] Currently, the mainstream shoulder joint prostheses on the market mainly fix the glenoid head on the glenoid socket in two ways. One is that a central fixing screw passes through the glenoid head and then is thread-connected with the glenoid socket to lock the glenoid head. The other is to fix the glenoid head on the glenoid socket through a taper connection, especially a Morse taper connection.

[0003] The central screw connection method fixes the glenoid head on the glenoid socket through the locking of the thread. Its fixing effect is very firm. However, since a screw hole will be added on the bearing surface of the glenoid head, friction will occur between the position of the screw hole and the matching part of the humeral liner during movement. In this case, the wear degree of the humeral liner is much greater than that when there is no screw hole on the glenoid head.

[0004] The Morse taper connection method can avoid adding a screw hole on the bearing surface of the glenoid head and can minimize the wear of the humeral liner. However, since it is installed in the body, it is very difficult to provide a large enough knocking force to the Morse taper connection part during assembly in the operation as in the external installation, so that the taper fit part can be locked tightly enough. And in the human body for a long time, the taper fit part will bear forces from different directions. Among them, there will inevitably be a part of the force that can be decomposed into an outward pulling force along the axial direction of the taper, and the action range is located in the glenoid head part. This pulling force may cause the reverse shoulder glenoid head to fall off. The pulling force can be very large and damage the taper fit part at one time, or it can be very small and act repeatedly for many times, continuously making the taper fit part loose.

[0005] Figure 1It is a schematic diagram of a glenoid head and a glenoid tray connected by a Morse taper in the prior art. In this case, the inner taper groove of the glenoid tray 1 applies an obliquely upward force F to the tapered structure 21 of the glenoid head 2. Force F can be decomposed into a horizontal pressure F1 and a vertical thrust F2. Among them, the thrust F2 acts outward along the central axis, making it easier to pull out the glenoid head 2. Since the assembly process is completed inside the human body and the glenoid cannot withstand a large knocking force, it is very difficult to ensure that the tapered mating part is locked tightly enough by the knocking force. And the glenoid head 2 and the glenoid tray 1 will remain in the human body for a long time after the operation. This Morse taper connection part will bear forces from different directions, and among them, there will inevitably be some forces that can be decomposed into an outward pulling force along the longitudinal (axial) direction of the Morse taper connection, and the action range is located in the glenoid head part. This pulling force may cause the loosening or even detachment of the glenoid head 1. The existence of the above-mentioned thrust F2 undoubtedly exacerbates the above two risks.

[0006] In view of the above situation, there is an urgent need in the industry for a new shoulder joint prosthesis, which has a glenoid tray and a glenoid head that can be taperedly connected, and this connection can be locked by an auxiliary locking structure that cooperates with each other on the glenoid tray and the glenoid head, so as to avoid the wear of the humeral liner caused by the screw holes on the bearing surface of the glenoid head, and at the same time, it can avoid problems such as the inability to be firmly fixed due to insufficient knocking force during the in-vivo assembly of the Morse taper connection and the easy loosening or even detachment of the Morse taper connection after assembly in the body under the action of repeated pulling forces from different directions. Summary of the Invention

[0007] An object of the present invention is to provide a shoulder joint prosthesis, which has a glenoid tray and a glenoid head that can be taperedly connected, and this connection can be locked by an auxiliary locking structure that cooperates with each other on the glenoid tray and the glenoid head, so as to overcome or improve at least one defect in the above prior art.

[0008] To achieve the above object, the present invention provides a shoulder joint prosthesis, which includes a glenoid tray and a glenoid head, wherein: the glenoid tray has a rod portion and a bottom plate located at one end of the rod portion. An inner taper groove is provided in both the rod portion and the bottom plate, and the inner taper groove has an increasing cross-sectional diameter in the direction from the rod portion towards the bottom plate. The bottom plate has a locking portion in the direction opposite to the rod portion; the glenoid head has a head portion and a shank portion. At least a part of the end of the shank portion away from the head portion is a tapered structure, and the tapered structure can be taperedly mated with the inner taper groove. A locking protrusion is provided on the end of the shank portion close to the head portion.

[0009] In one embodiment, the locking portion longitudinally extends away from the rod portion from the bottom plate of the glenoid fossa holder, and a locking end protruding transversely inward is formed at the end of its extension. And when the conical structure is inserted into the inner conical groove to form a taper connection, the locking protrusion can be wholly or partly locked and held within the locking portion by the locking end.

[0010] In one embodiment, the locking protrusion includes a forward inclined surface substantially in the same taper direction as that of the conical structure and a reverse inclined surface in the opposite taper direction to that of the conical structure. Wherein, the forward inclined surface extends from the starting point of the forward inclined surface away from the conical structure to the highest point of the locking protrusion, and the starting point of the forward inclined surface coincides with the starting point of the tapered portion at the large-diameter end of the conical structure or is located between the starting point of the tapered portion and the head. Wherein, the reverse inclined surface extends from the highest point of the locking protrusion away from the starting point of the forward inclined surface to the starting point of the reverse inclined surface.

[0011] In one embodiment, the longitudinal height from the large-diameter end of the inner conical groove to the inner end face of the locking end is greater than the longitudinal height from the highest point of the locking protrusion to the starting point of the tapered portion of the conical structure, and less than or equal to the longitudinal height from the starting point of the tapered portion of the conical structure to the starting point of the reverse inclined surface, so that the locking end can be clamped on the reverse inclined surface.

[0012] In one embodiment, the difference between the radius at the highest point of the locking protrusion and the radius at the starting point of the reverse inclined surface is greater than 0.1 mm and less than 1 mm.

[0013] In one embodiment, the longitudinal height of the reverse inclined surface is greater than 1.4 mm.

[0014] In one embodiment, the diameter at the highest point of the locking protrusion is greater than the diameter at the starting point of the tapered portion of the conical structure.

[0015] In one embodiment, the inner diameter of the locking portion is greater than or equal to the diameter at the starting point of the tapered portion of the conical structure.

[0016] In one embodiment, the taper angle of the reverse inclined surface is greater than the taper angle of the forward inclined surface.

[0017] In one embodiment, the handle portion is cylindrical from the part where it is connected to the head to the starting point of the reverse inclined surface, and the diameter of this cylindrical part is greater than the inner diameter φ of the locking portion. And when the starting point of the forward inclined surface is located between the starting point of the tapered portion and the head, the part from the starting point of the tapered portion of the conical structure to the starting point of the forward inclined surface is cylindrical or conical.

[0018] In one embodiment, the locking portion has one or more openings extending longitudinally.

[0019] In one embodiment, the tapered structure is a Morse taper.

[0020] The shoulder joint prosthesis of the present invention has a scapula glenoid support and a scapula glenoid head that can be connected in a tapered manner, and both have an auxiliary locking structure that cooperates with each other. The locking structure is a locking structure that is added on the basis of a tapered connection (especially a Morse taper connection) and can prevent the tapered connection from loosening. The shoulder joint prosthesis of the present invention has at least one of the following beneficial technical effects:

[0021] The shoulder joint prosthesis of the present invention does not have a screw hole necessary for threaded connection, and will not increase the wear of the bearing surface on the humeral liner.

[0022] The locking structure on the shoulder joint prosthesis of the present invention can provide an anti-pullout force that acts inward along the taper axis and continuously, and this force can increase the knocking force when the scapular glenoid head is assembled, making the assembly more secure.

[0023] The anti-pullout force provided by the locking structure on the shoulder joint prosthesis of the present invention can preferentially offset part of the axial outward pullout force exerted on the glenoid head, protect the Morse taper connection, and reduce the risk of loosening and falling off of the glenoid head.

[0024] The auxiliary locking structure on the shoulder joint prosthesis of the present invention is an elastic structure, which has the ability to automatically rebound before complete failure. Compared with the irreversibility of the single-direction failure of the tapered part, the auxiliary locking structure has obvious advantages when withstanding repeated pull-out forces of smaller forces. Its failure only occurs after the tapered fit fails completely, and it will continue to maintain the stability of the enhanced tapered fit before the tapered fit fails. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various objects, features and advantages of the present invention will become more apparent by considering the following detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are merely illustrative illustrations of the present invention and are not necessarily drawn to scale. In the accompanying drawings, the same reference numerals always refer to the same or similar parts. Among them:

[0026] Figure 1 The present invention is a schematic diagram of a scapular glenoid head and a scapular glenoid support connected by a Morse taper in the prior art.

[0027] Figure 2 2 is a three-dimensional schematic diagram of a scapular glenoid support with a locking portion according to an embodiment of the present invention.

[0028] Figure 3 is a cross-sectional view of a scapular glenoid support with a locking portion according to an embodiment of the present invention.

[0029] Figure 4 is a cross-sectional view of a glenoid head with a locking protrusion according to an embodiment of the present invention.

[0030] Figure 5 is Figure 4 an enlarged view of part I in

[0031] Figure 6 is Figure 3 a cross-sectional view after the glenoid socket holder shown in Figure 4 is connected to the glenoid head shown in

[0032] Figure 7 is Figure 6 an enlarged view of part II in

[0033] Description of reference numerals:

[0034] 1 Glenoid socket holder

[0035] 11 Locking part

[0036] 110 Locking wall

[0037] 111 Latching end

[0038] 112 Opening

[0039] 113 Inner end face

[0040] 12 Base plate

[0041] 13 Rod part

[0042] 14 Inner tapered groove

[0043] 2 Glenoid head

[0044] 20 Head

[0045] 205 Ring groove

[0046] 21 Tapered structure

[0047] 22 Locking projection

[0048] 221 Forward inclined plane

[0049] 222 Reverse inclined plane

[0050] 29 Shank

[0051] F, F1, F2 Forces

[0052] Fa, Fb, Fc Forces

[0053] α Morse taper angle

[0054] Inner diameter of the locking part

[0055] θ1, θ2 Taper angles

[0056] Vertical heights h1, h2, h3

[0057] Distance between A and B

[0058] Starting point M of the conical part

[0059] Starting point N of the positive inclined plane

[0060] Starting point O of the reverse inclined plane

[0061] Highest point P of the locking projection Detailed implementation mode

[0062] The present invention will be further described in detail below with reference to the accompanying drawings.

[0063] Figure 2 is a three-dimensional schematic diagram of a glenoid fossa tray with a locking part according to an embodiment of the present invention. Figure 3 is a cross-sectional view of a glenoid fossa tray with a locking part according to an embodiment of the present invention. Figure 4 is a cross-sectional view of a glenoid fossa head with a locking projection according to an embodiment of the present invention. In an embodiment of the present invention, the shoulder joint prosthesis includes a glenoid fossa tray 1 and a glenoid fossa head 2.

[0064] Refer to Figure 2 and Figure 3 , in an embodiment of the present invention, the glenoid fossa tray 1 includes a rod part 13 in the shape of an approximate cylinder and a bottom plate 12 located at the periphery of one end of the rod part 13. An inner conical groove 14 is provided inside both the rod part 13 and the bottom plate 12. The inner conical groove 14 has an increasing cross-sectional diameter in the direction from the rod part 13 towards the bottom plate 12 ( Figure 3 the upward direction in

[0065] In one embodiment, the inner conical groove 14 has a Morse taper.

[0066] Figure 4 Schematically shows the glenoid fossa head 2, which has a head 20 and a shank 29. At least a part of one end of the shank 29 away from the head 20 ( Figure 4 the lower end in

[0067] In one embodiment, the conical structure 21 has a Morse taper. At this time, the conical structure 21 and the inner conical groove 14 achieve Morse taper fit, so as to realize the Morse taper connection between the glenoid head 2 and the glenoid socket 1.

[0068] The locking portion 11 located on the glenoid socket 1 and the locking protrusion 22 located on the glenoid head 2 cooperate with each other to assist the taper connection between the glenoid socket 1 and the glenoid head 2.

[0069] The locking portion 11 includes a locking wall 110 extending from the bottom plate 12 in the vertical direction opposite to the rod portion 13 (shown as the vertically upward direction in the figure). The locking wall 110 encloses a ring shape and has a locking end 111 protruding inward at its end. Specifically, the locking portion 11 extends longitudinally outward from the end with a larger diameter of the inner conical groove 14 of the glenoid socket 1, and forms a locking end 111 protruding laterally inward at its extending end.

[0070] Continue as Figure 4 shown, in one embodiment of the present invention, the locking protrusion 22 is located above the handle portion 29, specifically between the starting point M of the conical portion at the large diameter end of the conical structure 21 and the head 20 of the glenoid head 2. When the conical structure 21 is inserted into the inner conical groove 14 and a taper connection is formed, the locking protrusion 22 can be completely or partially locked and held within the locking portion 11 by the locking end 111.

[0071] The head 20 of the glenoid head 2 is, for example, approximately hemispherical, and has an inwardly recessed annular groove 205 around the handle portion 29 on its inner side. The outer peripheral wall of the annular groove 205 covers the locking protrusion 22 longitudinally. That is, the outer diameter of the annular groove 205 is smaller than the outer diameter of the head 20, but larger than the outer diameter of the locking portion 11, so that when a taper connection is formed between the glenoid head 2 and the glenoid socket 1, the locking portion 11 can be accommodated in the annular groove 205. The conical structure 21 has a taper corresponding to the inner conical groove 14 so that it can be inserted into the inner conical groove 14 to form a taper connection. In one embodiment, the taper is a Morse taper.

[0072] The locking protrusion 22 includes a forward inclined surface 221 substantially in the same direction as the taper direction of the conical structure 21 and a reverse inclined surface 222 opposite to the taper direction of the conical structure 21.

[0073] Among them, the conical structure 21 has a forward inclined surface starting point N between the starting point M of the conical portion and the head 20. The forward inclined surface 221 extends from the forward inclined surface starting point N away from the starting point M of the conical portion to the highest point P of the locking protrusion 22, while the reverse inclined surface 222 extends from the highest point P of the locking protrusion 22 away from the forward inclined surface starting point N to a reverse inclined surface starting point O. In other words, the reverse inclined surface 222 extends from Figure 4The reverse bevel starting point O shown extends to the highest point P, so that the locking end 111 can be placed on the reverse bevel 222. Among them, as Figure 4 shown, the forward bevel starting point N is located between the cone starting point M and the head 20. Between the forward bevel starting point N and the cone starting point M on the handle 29 (that is, between the locking protrusion 22 and the conical structure 21) is cylindrical or conical, etc. with an appropriate diameter.

[0074] In another embodiment, the forward bevel starting point N can also coincide with the cone starting point M at the large diameter end of the conical structure 21 (not shown in the figure), that is, the locking protrusion 22 is adjacent to the conical structure 21.

[0075] Figure 6 is Figure 3 the cross-sectional view after the glenoid tray shown is connected to Figure 4 the glenoid head shown.

[0076] During reverse shoulder arthroplasty, generally, the glenoid tray is first installed on the glenoid, and then the glenoid head is assembled on the glenoid tray through a taper connection (in particular, Morse taper connection).

[0077] As Figure 6 shown, in an embodiment of the present invention, the conical structure 21 of the glenoid head 2 is inserted into the inner conical groove 14 of the glenoid tray 1, and a Morse taper connection is formed by tapping. Generally speaking, the Morse taper connection between the conical structure 21 and the inner conical groove 14 is a rigid connection. The locking end 111 of the locking wall 110 of the locking part 11 slides along the locking protrusion 22, crosses the highest point of the locking protrusion 22 and is stuck on the reverse bevel 222 above the locking protrusion 22. Among them, the locking part 11 and the locking protrusion 22 cooperate with each other to prevent the taper connection between the glenoid head and the glenoid tray from loosening, and the two can be collectively referred to as an auxiliary locking structure.

[0078] In one embodiment, the locking part 11 is provided with one or more longitudinally extending openings 112, so that the locking part 11 forms an elastic structure, which is beneficial for the locking end 111 of the locking wall 110 to cross the highest point of the locking protrusion 22 and achieve elastic clamping. Of course, the number of the openings 112 is not limited in the present invention, and different numbers of openings 112 can be set according to the situation. The openings preferably can have a shape with a wider upper part and a narrower lower part, so as to increase the degree to which the locking end can be widened as much as possible without reducing its elasticity. In addition, the openings 112 can be designed into various shapes, for example, vertical slots plus inverted circles (as shown in the figure), rounded rectangles, etc., and are not limited to those described and shown in the invention.

[0079] As Figure 7As shown, above the Morse taper connection, a continuous force Fa is applied by the locking portion 11 according to an embodiment of the present invention. This force can be decomposed into a horizontal pressure Fc and an anti-pull-out force Fb acting downward along the axial direction. The anti-pull-out force Fb is in the same direction as the knocking force, relatively increasing the knocking force, so that the tapered mating part can be locked tightly enough during the operation; at the same time, after the operation, the anti-pull-out force Fb continues to act, offsetting the pull-out force such as F2, so that the glenoid head is firmly fixed for a long time. In one embodiment, the anti-pull-out force Fb applied by the locking portion on the locking protrusion can be between 50N and 500N.

[0080] It should be noted that during the knocking process, the locking end 111 of the locking wall 110 of the locking portion 11 reaches the reverse inclined surface 222 first, and then the Morse taper connection is locked, and the auxiliary locking structure enters the locking state. And the maximum knocking force when passing through the highest point of the locking protrusion 22 is still much smaller than the knocking force required for locking the Morse taper connection. Thus, the locking end 111 can smoothly cross the highest point of the locking protrusion 22 and finally get stuck on the reverse inclined surface 222.

[0081] Figure 5 is Figure 4 an enlarged view of part I in. Figure 7 is Figure 6 an enlarged view of part II in. The following refers to Figures 3 - 7 describe a shoulder joint prosthesis according to an embodiment of the present invention.

[0082] As Figure 4 、 Figure 5 shown, the distance B in the figure is the difference between the radius at the highest point P of the locking protrusion 22 and the radius at the starting point N of the positive inclined surface, and the distance A is the difference between the radius at the highest point P of the locking protrusion 22 and the radius at the starting point O of the reverse inclined surface 222 of the reverse inclined surface. Obviously, the distance A and the distance B are greater than 0. In one embodiment, B is 0.475mm.

[0083] To ensure that during the assembly process, the locking portion bears little resistance when gradually passing through the locking protrusion, the difference A between the radius at the highest point P of the locking protrusion 22 and the radius at the starting point O of the reverse inclined surface is preferably greater than 0.1mm and less than 1mm. In one embodiment, A is 0.3mm.

[0084] The diameter D at the starting point M of the tapered portion of the tapered structure 21 is the maximum diameter of the tapered portion on the tapered structure 21 that mates with the inner tapered groove 14 of the glenoid socket 1. This diameter D can be determined according to actual needs. In one embodiment, this diameter D is 8.45mm.

[0085] Thus, since in Figures 4 - 5In the illustrated embodiment, the portion between the locking protrusion 22 and the conical structure 21 is cylindrical with a diameter D. Therefore, the diameter at the highest point P of the locking protrusion 22 is D + 2B, which is clearly greater than the diameter D at the large-diameter end of the conical structure 21.

[0086] The inner diameter of the locking portion 11 is greater than or equal to the diameter D at the large-diameter end of the conical structure 21 so that the conical surface of the conical structure 21 will not be scratched when being installed. In one embodiment, the inner diameter of the locking portion 11 is 8.8 mm

[0087] In an embodiment of the present invention, the diameter C at the starting point O of the reverse inclined surface of the conical structure 21 is greater than the inner diameter φ of the locking portion 11, thereby ensuring that the locking portion has a continuous elastic force. Preferably, on the handle portion 29, the portion from the connection part of the handle portion and the head portion 20 to the starting point O of the reverse inclined surface is cylindrical with a diameter C.

[0088] Referring to Figures 3 - 5 , the longitudinal height h3 from the large-diameter end of the inner conical groove 14 to the inner end face 113 of the locking end 111 is greater than or equal to the longitudinal height h2 from the highest point P of the locking protrusion 22 to the starting point M of the conical portion of the conical structure 21, so that the locking end 111 can be locked on the reverse inclined surface 222. In one embodiment, h3 is 4.5 mm. In one embodiment, h2 is 2 mm.

[0089] Since the tolerance of the taper angle α of the Morse taper is ±0°2’30”, to ensure that the auxiliary locking structure exactly falls on the reverse inclined surface, preferably, the longitudinal height h1 (the height from the highest point P of the locking protrusion 22 to the starting point O of the reverse inclined surface) of the reverse inclined surface 222 is greater than 1.4 mm. With the same distance A, the smaller h1 is, the larger the reverse inclined surface angle is, and the greater the axial anti-pulling force provided by the auxiliary locking structure is. Therefore, preferably, on the basis of being greater than 1.4 mm, h1 is as small as possible. For example, h1 can be 1.41 mm. With the same distance B, the larger h2 is, the smoother the locking portion 11 passes through the positive inclined surface, and the easier it is to pass through. However, h2 must be less than or equal to the height h3 above the inner cone with which it cooperates, that is, h2 ≤ h3. Similarly, to ensure that the locking end 111 exactly falls on the reverse inclined surface, the sum of the longitudinal height h2 and the longitudinal height h1 can be greater than or equal to the longitudinal height h3.

[0090] In addition, as Figure 5As shown, the starting point O of the reverse inclined plane is connected to the starting point N of the forward inclined plane by a straight line (dashed line). In this text, the angle θ1 formed between the reverse inclined plane 222 and this straight line is called the taper angle of the reverse inclined plane, and the angle θ2 formed between the forward inclined plane 221 and this straight line is called the taper angle of the forward inclined plane. In this embodiment, the taper angle of the reverse inclined plane is greater than that of the forward inclined plane, which is conducive to the locking protrusion 22 easily entering the locking portion 11 and being locked by the locking end 111, and not being easily pulled out from the locking portion 11. Preferably, the taper angle θ1 of the reverse inclined plane 222 is 12.1°. Preferably, the taper angle θ2 of the forward inclined plane 221 is about 10°.

[0091] During the reverse shoulder joint replacement process, generally, the glenoid tray is first installed on the glenoid, and then the glenoid head is assembled on the glenoid tray through taper fit. Since the assembly process is completed inside the human body, it is very difficult to ensure that the taper fit part is locked tightly enough by the knocking force. At this time, the auxiliary locking device can provide an additional force that continuously acts inward along the axial direction, and after superposition, the knocking force is relatively increased, so that the taper fit part is locked. It should be noted that during the knocking process, the locking structure at the upper part of the taper fit reaches the position first and enters the auxiliary locking state, and the maximum knocking force when passing through the protrusion position is much smaller than the knocking force required for taper locking.

[0092] After the glenoid tray and the glenoid head in the shoulder joint prosthesis according to the embodiment of the present invention complete the Morse taper connection, during a long time after the operation inside the human body, the Morse taper connection part will bear forces from different directions. Among them, a part of the force will inevitably be decomposed into an outward pulling force along the axial direction of the Morse taper connection, and the action range is located in the glenoid head part. This pulling force may cause the glenoid head to fall off. The above-mentioned pulling force may be very large and can damage the taper connection part at one time, or it may be very small. Through multiple and repeated actions, it continuously makes the Morse taper connection part loose. The pulling force acts on the glenoid head part, and the auxiliary locking structure is located above the Morse taper connection part, and will bear the pulling force prior to the Morse taper connection part. If the pulling force is very large, the auxiliary locking structure can offset a part of the outward pulling force along the axial direction of the Morse taper connection, reducing the risk of failure of the Morse taper connection part; if the pulling force is very small, it will inevitably reduce or even offset the pulling force, greatly reducing the risk of loosening of the Morse taper connection part. It should be noted that the auxiliary locking structure is an elastic structure, and it has the ability of automatic rebound before complete failure. Compared with the irreversibility of the single-direction failure of the Morse taper connection, the auxiliary locking structure has obvious advantages when bearing the repeated pulling force of a small force, and its failure only occurs after the complete failure of the Morse taper connection, and it will continuously maintain and enhance the stability of the Morse taper connection before the failure of the Morse taper connection.

[0093] It should be understood that although the preferred embodiments are shown and described above, the invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications and variations without departing from the spirit and scope of the appended claims. Therefore, it should be noted that various modifications and variations should not be regarded as exceeding the technical spirit and scope of the invention.

Claims

1. A shoulder joint prosthesis, comprising a glenoid socket holder (1) and a glenoid head (2), wherein: The glenoid socket support (1) has a rod portion (13) and a bottom plate (12) located at one end of the rod portion. An inner tapered groove (14) is provided in both the rod portion (13) and the bottom plate (12). The inner tapered groove (14) has a Morse taper, and the inner tapered groove (14) has an increasing cross-sectional diameter in the direction from the rod portion (13) towards the bottom plate (12). The bottom plate (12) has a locking portion (11) in the direction opposite to the rod portion; The glenoid head (2) has a head portion (20) and a shank portion (29). At least a part of one end of the shank portion (29) far from the head portion (20) is a tapered structure (21). The tapered structure (21) can be in taper fit with the inner tapered groove (14). A locking protrusion (22) is provided on one end of the shank portion (29) close to the head portion (20), wherein the locking protrusion (22) includes a forward inclined surface (221) substantially in the same taper direction as the tapered structure (21) and a reverse inclined surface (222) in the opposite taper direction to the tapered structure (21), wherein the forward inclined surface (221) extends from the starting point (N) of the forward inclined surface away from the tapered structure (21) to the highest point (P) of the locking protrusion (22). The starting point (N) of the forward inclined surface coincides with the starting point (M) of the tapered portion at the large diameter end of the tapered structure (21) or is located between the starting point (M) of the tapered portion and the head portion (20), wherein the reverse inclined surface (222) extends from the highest point (P) of the locking protrusion (22) away from the starting point (N) of the forward inclined surface to the starting point (O) of the reverse inclined surface.

2. The shoulder joint prosthesis according to claim 1, wherein, The locking portion (11) longitudinally extends from the bottom plate (12) of the glenoid socket support (1) away from the rod portion (13) and forms a locking end (111) protruding laterally inwards at its extending end, and when the tapered structure (21) is inserted into the inner tapered groove (14) to form a taper connection, the locking protrusion (22) can be completely or partially locked and held within the locking portion (11) by the locking end (111).

3. The shoulder joint prosthesis according to claim 2, wherein, The longitudinal height (h3) from the large diameter end of the inner tapered groove (14) to the inner end face (113) of the locking end (111) is greater than the longitudinal height (h2) from the highest point (P) of the locking protrusion (22) to the starting point (M) of the tapered portion of the tapered structure (21), and less than or equal to the longitudinal height from the starting point (M) of the tapered portion of the tapered structure (21) to the starting point (O) of the reverse inclined surface, so that the locking end (111) can be clamped on the reverse inclined surface.

4. The shoulder joint prosthesis according to claim 1, wherein, The difference (A) between the radius at the highest point (P) of the locking protrusion (22) and the radius at the starting point (O) of the reverse inclined surface is greater than 0.1 mm and less than 1 mm.

5. The shoulder joint prosthesis according to claim 3, wherein, The longitudinal height (h1) of the reverse inclined surface (222) is greater than 1.4 mm.

6. The shoulder joint prosthesis according to claim 1, wherein, The diameter at the highest point (P) of the locking protrusion (22) is greater than the diameter (D) at the starting point (M) of the tapered portion of the tapered structure (21).

7. The shoulder joint prosthesis according to claim 1, wherein, The inner diameter (φ) of the locking portion (11) is greater than or equal to the diameter (D) at the starting point (M) of the tapered portion of the tapered structure (21).

8. The shoulder joint prosthesis according to claim 1, wherein, The taper angle of the reverse inclined surface (222) is greater than the taper angle of the forward inclined surface (221).

9. The shoulder joint prosthesis according to claim 1, wherein, The handle portion (29) is cylindrical from the portion where it is connected to the head portion (20) to the starting point (O) of the reverse inclined surface, and the diameter (C) of this cylindrical portion is greater than the inner diameter (φ) of the locking portion (11), and when the starting point (N) of the forward inclined surface is located between the starting point (M) of the tapered portion and the head portion (20), the portion between the starting point (M) of the tapered structure (21) and the starting point (N) of the forward inclined surface is cylindrical or conical.

10. The shoulder joint prosthesis according to claim 1, wherein, The locking portion (11) has one or more openings (112) extending longitudinally.

11. The shoulder joint prosthesis according to claim 1, wherein, The tapered structure (21) has a Morse taper.

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