阅读说明：本技术 肩关节假体 (Shoulder joint prosthesis ) 是由 胡肖强 张晓永 徐凯 许慧 赵军 董骧 于 2018-08-24 设计创作，主要内容包括：本公开涉及一种肩关节假体,其包括肩胛盂托(1)和肩胛盂头(2),其中：所述肩胛盂托(1)具有杆部(13)和位于杆部一端的底板(12),所述杆部(13)和所述底板(12)两者内设有一内锥槽(14),该内锥槽(14)在从所述杆部(13)朝向所述底板(12)的方向上具有渐增的横截面直径,所述底板(12)在与杆部相反的方向上具有锁紧部(11)；所述肩胛盂头(2)具有头部(20)和柄部(29),所述柄部(29)的远离所述头部(20)的一端的至少一部分为锥形结构(21),所述锥形结构(21)可与所述内锥槽(14)锥度配合,所述柄部(29)的靠近所述头部(20)的一端上具有锁紧凸起(22)。(The present disclosure relates to a shoulder joint prosthesis comprising a scapular glenoid tray (1) and a scapular glenoid head (2), wherein: the glenoid tray (1) has a rod portion (13) and a base plate (12) at one end of the rod portion, an inner tapered groove (14) is provided in both the rod portion (13) and the base plate (12), the inner tapered groove (14) has an increasing cross-sectional diameter in a direction from the rod portion (13) toward the base plate (12), and the base plate (12) has a locking portion (11) in a direction opposite to the rod portion; the scapula head (2) is provided with a head part (20) and a handle part (29), at least one part of one end of the handle part (29) far away from the head part (20) is a conical structure (21), the conical structure (21) can be in taper fit with the inner conical groove (14), and one end of the handle part (29) close to the head part (20) is provided with a locking protrusion (22).)

1. A shoulder joint prosthesis comprising a scapular glenoid tray (1) and a scapular glenoid head (2), wherein:

the glenoid tray (1) has a rod portion (13) and a base plate (12) at one end of the rod portion, an inner tapered groove (14) is provided in both the rod portion (13) and the base plate (12), the inner tapered groove (14) has an increasing cross-sectional diameter in a direction from the rod portion (13) toward the base plate (12), and the base plate (12) has a locking portion (11) in a direction opposite to the rod portion;

the scapula head (2) is provided with a head part (20) and a handle part (29), at least one part of one end, far away from the head part (20), of the handle part (29) is a conical structure (21), the conical structure (21) can be in taper fit with the inner conical groove (14), and one end, close to the head part (20), of the handle part (29) is provided with a locking protrusion (22).

2. The shoulder joint prosthesis according to claim 1, wherein the locking portion (11) longitudinally extends from the bottom plate (12) of the scapula tray (1) away from the stem portion (13) and forms a laterally inwardly protruding retaining end (111) at an extending tip thereof, and

the locking protrusion (22) can be retained in the locking portion (11) by the retaining end (111) in a complete or partial retaining manner when the tapered structure (21) is inserted into the internal tapered groove (14) to form a tapered connection.

3. The shoulder joint prosthesis according to claim 2, wherein the locking protrusion (22) comprises a forward slope (221) substantially in the same direction as the direction of taper of the tapered structure (21) and a reverse slope (222) opposite to the direction of taper of the tapered structure (21),

wherein the forward slope (221) extends from a forward slope starting point (N) away from the cone structure (21) to a highest point (P) of the locking protrusion (22), wherein the forward slope starting point (N) coincides with a cone starting point (M) at a large diameter end of the cone structure (21) or is located between the cone starting point (M) and the head (20),

wherein the reverse slope (222) extends from a highest point (P) of the locking projection (22) away from the forward slope start (N) to a reverse slope start (O).

4. The shoulder joint prosthesis according to claim 3, wherein a longitudinal height (h3) of the large-diameter end of the inner taper groove (14) from the inner end surface (113) of the locking end (111) is greater than a longitudinal height (h2) of the highest point (P) of the locking protrusion (22) from a taper start point (M) of the tapered structure (21) and is equal to or less than a longitudinal height (h1+ h2) of the taper start point (M) of the tapered structure (21) from the reverse slope start point (O) so that the locking end (111) can be locked on the reverse slope.

5. A shoulder joint prosthesis according to claim 3, wherein the difference (a) between the radius at the highest point (P) of the locking projection (22) and the radius at the starting point (O) of the reverse bevel is greater than 0.1mm and less than 1 mm.

6. The shoulder joint prosthesis of claim 4, wherein the longitudinal height (h1) of the reverse bevel (222) is greater than 1.4 mm.

7. The shoulder joint prosthesis according to claim 3, wherein the diameter at the highest point (P) of the locking projection (22) is larger than the diameter (D) at the start of taper (M) of the tapered structure (21).

8. A shoulder joint prosthesis according to claim 3, wherein the locking portion (11) has an inner diameter

9. The shoulder joint prosthesis of claim 3, wherein the taper angle of the reverse bevel (222) is greater than the taper angle of the forward bevel (221).

10. A shoulder joint prosthesis according to claim 3, wherein the stem (29) has a cylindrical shape from its connection point with the head (20) to the starting point (O) of the counter slope, the diameter (C) of the cylindrical portion being greater than the inner diameter of the locking portion (11)

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

12. The shoulder joint prosthesis according to claim 1, wherein the tapered structure (21) is in a morse taper.

Technical Field

The invention relates to a shoulder joint prosthesis, in particular to a shoulder joint prosthesis used in reverse shoulder joint replacement, which is provided with a scapula support and a scapula head capable of performing taper connection, in particular Mohs taper connection.

Background

The main stream of shoulder joint prosthesis in the market at present fixes the scapular glenoid head on the scapular glenoid support mainly through two modes, one mode is that a central fixing screw penetrates through the scapular glenoid head and then is connected with the scapular glenoid support through threads to lock the scapular glenoid head; the other is to fix the scapular glenoid head on the scapular glenoid support through taper connection, especially Mohs taper connection.

The central screw connection mode is to fix the scapula head on the scapula support through the locking of the screw thread, the fixing effect is very firm, but because a screw hole can be added on the bearing surface of the scapula head, the position of the nail hole can generate friction with the matched humeral liner part during movement, and the abrasion degree of the humeral liner under the condition is far greater than that under the condition that the scapula head is not provided with the nail hole.

The Morse taper connection mode can avoid adding screw holes on the bearing surface of the scapular head, can reduce the abrasion of the humeral liner to the utmost extent, but because the Morse taper connection mode is installed in vivo, when the Morse taper connection part is assembled in an operation, the Morse taper connection part is difficult to provide enough striking force like in vitro installation, the taper fit part is locked tightly enough, and in a human body for a long time, the taper fit part can bear the force from different directions, wherein, part of the force can be decomposed into the extraction force outwards along the axial direction of the taper, the action range is positioned at the scapular head part, and the extraction force can possibly cause the falling of the scapular head. The pull-out force can be very large, the taper fit part can be damaged at one time, and the pull-out force can also be very small, and can be repeatedly acted for a plurality of times to continuously loosen the taper fit part.

FIG. 1 is a schematic representation of a prior art scapuloglenoid head and scapuloglenoid tray connected using a Morse taper. In this case, the inner taper of the scapula holder 1 can apply an upward force F to the tapered structure 21 of the scapula head 2, which can be decomposed into a horizontal pressure F1 and a vertical thrust F2, wherein the thrust F2 is outward in the direction of the central axis, making the scapula head 2 easier to be extracted. Because the assembly process is completed in a human body, the scapular pelvis cannot bear large knocking force, and therefore, the taper matching part is difficult to be locked tightly enough through the knocking force; the scapula head 2 and the scapula support 1 can be left in a human body for a long time after operation, the Morse taper connecting part can bear forces from different directions, a part of the forces can be decomposed into an outward pulling force along the longitudinal (axial) direction of the Morse taper connection, the acting range is positioned at the scapula head part, and the pulling force can cause the scapula head 1 to loosen and even fall off. The presence of the thrust force F2 clearly exacerbates both of these risks.

In view of the above circumstances, there is a need in the industry for a new shoulder joint prosthesis, which has a scapular socket and a scapular head capable of taper connection, and the connection can be locked by an auxiliary locking structure on the scapular socket and the scapular head, so as to avoid abrasion of the scapular socket bearing surface to the humeral liner due to the screw hole, and simultaneously avoid the problems that the fixation cannot be firmly achieved due to insufficient striking force when the morse taper connection is assembled in vivo, and the scapular socket is easy to loosen or even fall off due to repeated pulling force after the morse taper connection is assembled in vivo.

Disclosure of Invention

It is an object of the present invention to provide a shoulder joint prosthesis having a scapular socket and a scapular head that enable a taper connection that can be locked by complementary locking structures on the scapular socket and the scapular head that mate with each other to overcome or ameliorate at least one of the deficiencies of the prior art described above.

To achieve the above object, the present invention provides a shoulder joint prosthesis comprising a scapular glenoid tray and a scapular glenoid head, wherein: the scapula support is provided with a rod part and a bottom plate positioned at one end of the rod part, an inner taper groove is arranged in the rod part and the bottom plate, the inner taper groove has an increasing cross section diameter in the direction from the rod part to the bottom plate, and the bottom plate is provided with a locking part in the direction opposite to the rod part; the scapula head is provided with a head part and a handle part, at least one part of one end of the handle part, which is far away from the head part, is of a conical structure, the conical structure can be in taper fit with the inner taper groove, and one end of the handle part, which is close to the head part, is provided with a locking bulge.

In one embodiment, the locking part extends longitudinally from the bottom plate of the glenoid tray away from the rod part, and forms a locking end protruding laterally inwards at an extending end thereof, and the locking protrusion can be locked and held in the locking part by the locking end wholly or partially in a state that the tapered structure is inserted into the inner tapered groove and forms a taper connection.

In an embodiment, the locking protrusion comprises a forward slope substantially in the same direction as the direction of taper of the tapered structure and a reverse slope opposite to the direction of taper of the tapered structure, wherein the forward slope extends from a forward slope starting point away from the tapered structure to a highest point of the locking protrusion, wherein the forward slope starting point coincides with a taper portion starting point at the large diameter end of the tapered structure or is located between the taper portion starting point and the head, and wherein the reverse slope extends from the highest point of the locking protrusion away from the forward slope starting point to a reverse slope starting point.

In one embodiment, the longitudinal height of the large diameter end of the inner taper groove from the inner side end surface of the locking end is greater than the longitudinal height of the highest point of the locking protrusion from the starting point of the taper portion of the tapered structure and is less than or equal to the longitudinal height of the starting point of the taper portion of the tapered structure from the starting point of the reverse slope, so that the locking end can be clamped on the reverse slope.

In one embodiment, the difference between the radius at the highest point of the locking projection and the radius at the beginning of the reverse slope is greater than 0.1mm and less than 1 mm.

In one embodiment, the longitudinal height of the reverse incline is greater than 1.4 mm.

In one embodiment, the diameter of the locking projection at the highest point is greater than the diameter at the beginning of the taper of the tapered structure.

In one embodiment, the inner diameter of the locking portion is equal to or greater than the diameter at the beginning of the taper of the tapered structure.

In one embodiment, the taper angle of the reverse slope is greater than the taper angle of the forward slope.

In one embodiment, the shank has a cylindrical shape from a portion thereof connected to the head to the reverse slope starting point, the cylindrical portion having a diameter larger than an inner diameter Φ of the locking portion, and wherein the taper portion of the tapered structure has a cylindrical or conical shape from the taper portion starting point to the forward slope starting point in a state where the forward slope starting point is located between the taper portion starting point and the head.

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

In one embodiment, the tapered structure is a morse taper.

The shoulder joint prosthesis provided by the invention is provided with a scapula support and a scapula head which can be in taper connection, wherein the scapula support and the scapula head are provided with mutually matched auxiliary locking structures, the locking structures are locking structures which are added on the basis of taper connection (particularly Morse taper connection) and can prevent the taper connection from loosening, and the shoulder joint prosthesis provided by the invention has at least one of the following beneficial technical effects:

the shoulder joint prosthesis of the present invention does not have the screw holes necessary for threaded connection and does not increase wear of the bearing surface against the humeral liner.

The locking structure on the shoulder joint prosthesis can provide an anti-pulling force which is axially inwards along the taper and continuously acts, and the force can increase the knocking force during the assembly of the scapula glenoid head, so that the assembly is firmer.

The anti-extraction force provided by the locking structure on the shoulder joint prosthesis can preferentially offset the axial outward extraction force applied to part of the scapular glenoid head, protect Morse taper connection and reduce the risk of loosening and falling of the scapular glenoid head.

The auxiliary locking structure on the shoulder joint prosthesis is an elastic structure, has automatic resilience before complete failure, has obvious advantages when bearing repeated pull-out force of small force relative to the irreversibility of failure of a taper part in a single direction, and can continuously maintain the stability of enhanced taper fit before the taper fit fails when the condition of failure only occurs after the taper fit is completely failed.

Drawings

Various objects, features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, when considered in conjunction with the accompanying drawings. The drawings are merely exemplary of the invention and are not necessarily drawn to scale. In the drawings, like reference characters designate the same or similar parts throughout the different views. Wherein:

FIG. 1 is a schematic representation of a prior art scapuloglenoid head and scapuloglenoid tray connected using a Morse taper.

Fig. 2 is a perspective view of a glenoid tray having a locking portion according to an embodiment of the present invention.

Fig. 3 is a cross-sectional view of a glenoid tray having a locking portion in accordance with an embodiment of the present invention.

Fig. 4 is a cross-sectional view of a glenoid head having a locking tab in accordance with an embodiment of the present invention.

Fig. 5 is an enlarged view of a portion I in fig. 4.

Fig. 6 is a cross-sectional view of the glenoid tray shown in fig. 3 and the scapula head shown in fig. 4 after they are coupled together.

Fig. 7 is an enlarged view of a portion II in fig. 6.

Description of reference numerals:

1 scapular glenoid holder

11 locking part

110 locking wall

111 stop end

112 opening

113 inner end surface

12 bottom plate

13 rod part

14 inner taper groove

2 scapular glenoid head

20 head

205 ring groove

21 conical structure

22 locking projection

221 forward slope

222 reverse slope

29 handle part

F. F1 and F2 forces

Fa. Fb, Fc force

α Morse taper angle

Inner diameter of locking part

Theta 1 and theta 2 taper angles

h1, h2, h3 longitudinal height

A. Distance B

M Cone starting point

N forward slope starting point

Starting point of O reverse inclined plane

Highest point of P locking protrusion

Detailed Description

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

Fig. 2 is a perspective view of a glenoid tray having a locking portion according to an embodiment of the present invention. Fig. 3 is a cross-sectional view of a glenoid tray having a locking portion in accordance with an embodiment of the present invention. Fig. 4 is a cross-sectional view of a glenoid head having a locking tab in accordance with an embodiment of the present invention. In one embodiment of the invention, a shoulder joint prosthesis comprises a scapuloglenoid tray 1 and a scapuloglenoid head 2.

Referring to fig. 2 and 3, in one embodiment of the present invention, the glenoid tray 1 includes a substantially cylindrical stem portion 13 and a base plate 12 located at the periphery of one end of the stem portion 13, with an internal taper 14 being provided in both the stem portion 13 and the base plate 12. The inner tapered slot 14 has an increasing cross-sectional diameter in a direction from the stem portion 13 toward the base plate 12 (upward in fig. 3). The base plate 12 has a locking portion 11 in a direction opposite to the lever portion. The base plate 12 projects outwardly of the lever portion 13 in a radial direction perpendicular to the longitudinal direction of the glenoid tray 1 (i.e., the longitudinal direction of the lever portion 13), as well as the locking portion 11. The base plate 12 may be circular or any other suitable shape.

In one embodiment, the internal taper 14 is a Morse taper.

Fig. 4 schematically shows a scapula head 2 having a head 20 and a handle 29. At least a portion of the end of the shank 29 remote from the head 20 (the lower end in fig. 4) is a tapered structure 21. The tapered structure 21 may be a taper fit with the internal taper 14 in the scapular glenoid tray 1 to achieve the desired connection between the scapular glenoid head 2 and the scapular glenoid tray 1. The shank 29 has a locking projection 22 on one end adjacent the head 20.

In one embodiment, the tapered structure 21 has a Morse taper. At this time, the tapered structure 21 and the inner tapered groove 14 realize a morse taper fit, thereby realizing a morse taper connection between the scapula head 2 and the scapula support 1.

The locking part 11 on the scapula support 1 and the locking bulge 22 on the scapula head 2 are mutually matched for assisting the taper connection between the scapula support 1 and the scapula head 2.

The locking portion 11 includes a locking wall 110 extending from the base plate 12 in a vertical direction (vertically upward as viewed in the drawings) opposite the lever portion 13. The locking wall 110 is formed in 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 portion of the inner tapered groove 14 of the glenoid tray 1 having the larger diameter, and forms a laterally inwardly protruding locking end 111 at the extending end thereof.

Continuing with fig. 4, in an embodiment of the invention, the locking protrusion 22 is located above the stem 29, specifically between the taper origin M at the large diameter end of the tapered structure 21 and the head 20 of the scapula head 2. In the case where the tapered structure 21 is inserted into the inner tapered groove 14 and the taper connection is formed, the locking protrusion 22 may be retained in the locking portion 11 by the retaining end 111 in a complete or partial retaining manner.

The head 20 of the scapula head 2 is, for example, approximately hemispherical, with an inwardly recessed annular groove 205 around the stem 29 on the inside. The peripheral wall of the ring groove 205 covers the locking projection 22 in the longitudinal direction. That is, the outer diameter of the ring groove 205 is smaller than the outer diameter of the head portion 20, but larger than the outer diameter of the locking portion 11, so that the locking portion 11 can be received in the ring groove 205 when the taper connection is formed between the scapula head 2 and the scapula tray 1. The tapered structure 21 has a taper corresponding to the internal taper 14 so that it can be inserted into the internal taper 14 to form a tapered connection. In one embodiment, the taper is a Morse taper.

The locking projection 22 includes a forward slope 221 substantially in the same direction as the taper direction of the tapered structure 21 and a reverse slope 222 opposite to the taper direction of the tapered structure 21.

The taper structure 21 has a forward slope starting point N between the taper starting point M and the head 20, the forward slope 221 extends from the forward slope starting point N away from the taper starting point M to a highest point P of the locking protrusion 22, and the reverse slope 222 extends from the highest point P of the locking protrusion 22 away from the forward slope starting point N to a reverse slope starting point O, in other words, the reverse slope 222 extends from the reverse slope starting point O shown in fig. 4 to the highest point P, so that the locking end 111 can be locked on the reverse slope 222. As shown in fig. 4, the forward slope starting point N is located between the taper portion starting point M and the head portion 20. Between the forward slope starting point N and the taper starting point M on the shank 29 (i.e., between the locking protrusion 22 and the tapered structure 21), there is a column or a taper, etc. having an appropriate diameter.

In another embodiment, the positive slope starting point N may also coincide with the taper starting point M at the large diameter end of the tapered structure 21 (not shown in the figures), i.e. the locking protrusion 22 is immediately adjacent to the tapered structure 21.

Fig. 6 is a cross-sectional view of the glenoid tray shown in fig. 3 and the scapula head shown in fig. 4 after they are coupled together.

In the case of a reverse shoulder joint replacement, the scapular pelvis is generally mounted on the scapular pelvis, and then the scapular head is assembled on the scapular pelvis support by taper connection (in particular, morse taper connection).

As shown in FIG. 6, in one embodiment of the present invention, the tapered structure 21 of the scapula head 2 is inserted into the internal taper slot 14 of the scapula tray 1 and forms a Morse taper connection by tapping. Generally, the Morse taper connection between the tapered structure 21 and the inner taper 14 is a rigid connection. The catching end 111 of the locking wall 110 of the locking part 11 slides along the locking protrusion 22, goes over the highest point of the locking protrusion 22 and catches on the reverse slope 222 above the locking protrusion 22. Wherein, locking portion 11 and locking protrusion 22 mutually cooperate to prevent that the taper connection between scapula head and scapula support is not hard up, and both can jointly be called as supplementary locking structure.

In one embodiment, the locking portion 11 is provided with one or more longitudinally extending openings 112, such that the locking portion 11 is formed with a resilient structure to facilitate the latching end 111 of the locking wall 110 to pass over the highest point of the locking protrusion 22 and achieve a resilient snap fit. Of course, the number of the openings 112 is not limited in the present invention, and a different number of the openings 112 may be provided according to circumstances. The opening may preferably have a shape that is wide at the top and narrow at the bottom to increase the extent to which the locking end can be widened as much as possible without reducing its elasticity. In addition, the opening 112 may be designed in various shapes, such as a vertical slot plus an inverted circle (as shown), a rounded rectangle, etc., without being limited to that described and shown in the present invention.

As shown in fig. 7, above the morse taper connection, the locking portion 11 according to an embodiment of the present invention exerts a continuous force Fa that can be decomposed into a horizontal compressive force Fc and an anti-withdrawal force Fb downward in the axial direction. The anti-pull-out force Fb is in the same direction as the knocking force, and the knocking force is relatively increased, so that the taper fit part can be locked tightly enough in the operation; at the same time, this pullout resistance force Fb continues to act after the procedure, counteracting pullout forces such as F2, allowing the scapular glenoid to be held firmly for a long period of time. In one embodiment, the anti-pullout force Fb exerted by the locking portion on the locking projection can be between 50N-500N.

It should be noted that during the striking process, the stopping end 111 of the locking wall 110 of the locking portion 11 first reaches the reverse slope 222, and then the morse taper connection is locked, so as to assist the locking structure to enter the locking state, and the maximum striking force passing through the highest point of the locking protrusion 22 is still much smaller than the striking force required for locking the morse taper connection. Thus, the catching end 111 can smoothly pass over the highest point of the locking projection 22 and finally catch on the reverse slope 222.

Fig. 5 is an enlarged view of a portion I in fig. 4. Fig. 7 is an enlarged view of a portion II in fig. 6. A shoulder joint prosthesis according to an embodiment of the present invention will be described with reference to fig. 3 to 7.

As shown in fig. 4 and 5, the distance B is the difference between the radius of the highest point P of the locking protrusion 22 and the radius of the starting point N of the forward inclined surface, and the distance a is the difference between the radius of the highest point P of the locking protrusion 22 and the radius of the starting point O of the reverse inclined surface 222 of the reverse inclined surface. Obviously, the distance a, B is greater than 0. In one embodiment, B is 0.475 mm.

To ensure that the locking portion experiences little resistance as it passes over the locking projection during assembly, the difference a between the radius at the highest point P of the locking projection 22 and the radius at the starting point O of the reverse slope is preferably greater than 0.1mm and less than 1 mm. In one embodiment, A is 0.3 mm.

The diameter D at the starting point M of the taper of the tapered structure 21 is the maximum diameter of the taper on the tapered structure 21 that mates with the internal taper 14 of the glenoid tray 1. The diameter D can be determined according to practical requirements. In one embodiment, the diameter D is 8.45 mm.

Thus, since in the embodiment shown in fig. 4-5 the locking protrusion 22 and the conical structure 21 are cylindrical with a diameter D, the diameter at the highest point P of the locking protrusion 22 is D +2B, which is obviously larger than the diameter D at the large diameter end of the conical structure 21.

Inner diameter of the locking portion 11

Greater than or equal to the diameter D at the large diameter end of the conical structure 21 so that the locking portion 11 does not scratch the conical surface of the conical structure 21 when installed. In one implementationIn this example, the inner diameter of the locking portion 11

Is 8.8mm

In the embodiment of the present invention, the diameter C of the tapered structure 21 at the starting point O of the reverse slope is larger than the inner diameter Φ of the locking portion 11, thereby ensuring that the locking portion has a continuous elastic force. Preferably, the shank 29 has a cylindrical shape with a diameter C from a portion where the shank is connected to the head 20 to the starting point O of the reverse slope.

Referring to fig. 3 to 5, a longitudinal height h3 of the large diameter end of the inner tapered groove 14 from the inner side end surface 113 of the locking end 111 is equal to or greater than a longitudinal height h2 of the highest point P of the locking protrusion 22 from the taper start point M of the tapered structure 21 so that the locking end 111 can be locked on the reverse slope 222. In one embodiment, h3 is 4.5 mm. In one embodiment, h2 is 2 mm.

Since the tolerance of the taper angle α of the morse taper is ± 0 ° 2' 30 ", in order to ensure that the auxiliary locking structure just falls on the reverse slope, it is preferable that the longitudinal height h1 of the reverse slope 222 (the height of the highest point P of the locking protrusion 22 from the starting point O of the reverse slope) is greater than 1.4mm, in the case of the same distance a, the smaller h1 is, the larger the angle of the reverse slope is, the larger the axial withdrawal resistance provided by the auxiliary locking structure is, and therefore, it is preferable that the value of h1 is as small as possible on the basis of greater than 1.4mm, for example, h1 may be 1.41mm, and the larger h2 is in the case of the same distance B, the gentler 8656 is the easier the locking portion 11 passes through the forward slope, but h2 must be smaller than or equal to the height h3 above the inner cone matched therewith, that is h2 ≦ h3., and also, in order to ensure that the locking end 111 just falls on the reverse slope, the sum of the longitudinal height h1 may be greater than or equal to.

As shown in fig. 5, the reverse slope starting point O and the forward slope starting point N are connected by a straight line (broken line), an angle θ 1 formed by the reverse slope 222 and the straight line is referred to as a taper angle of the reverse slope, and an angle θ 2 formed by the forward slope 221 and the straight line is referred to as a taper angle of the forward slope, and in the present embodiment, the taper angle of the reverse slope is larger than the taper angle of the forward slope, so that the locking protrusion 22 can easily enter the locking portion 11 and be locked by the locking end 111, and can not be easily pulled out from the locking portion 11. Preferably, the taper angle θ 1 of the reverse slope 222 is 12.1 °. Preferably, the taper angle θ 2 of the forward slope 221 is about 10 °.

In the reverse shoulder joint replacement process, generally, the scapula is firstly supported on the scapula, and then the scapula head is assembled on the scapula support through taper fit. It should be noted that, during the knocking process, the locking structure at the upper part of the taper fit reaches the position and enters the auxiliary locking state, and the maximum knocking force passing through the protruding position is far smaller than the knocking force required by the taper locking.

After the glenoid holder and the glenoid head in the shoulder joint prosthesis according to the embodiment of the invention complete the morse taper connection, the morse taper connection part can bear forces from different directions in a human body for a long time after operation, wherein a part of the forces can be decomposed into an outward pulling force along the axial direction of the morse taper connection, the acting range is positioned at the glenoid head part, and the pulling force can cause the glenoid head to fall off. The pull-out force may be large and may damage the taper connecting portion at one time, or may be small, and the Morse taper connecting portion may be continuously loosened through repeated action. The extraction force acts on the scapular glenoid head part, and the auxiliary locking structure is positioned above the Morse taper connecting part and can bear the extraction force in preference to the Morse taper connecting part. If the pulling force is large, the auxiliary locking structure can counteract a part of pulling force which is outward along the axial direction of the Morse taper connection, and the risk of failure of the Morse taper connection part is reduced; if the extraction force is small, it will necessarily reduce or even counteract the extraction force, greatly reducing the risk of loosening of the morse taper connection. It should be noted that the auxiliary locking structure is an elastic structure, which has an automatic resilience before complete failure, and has an obvious advantage in repeated withdrawal force with a small force when compared with the irreversibility of single-direction failure of the morse taper connection, and the failure condition of the auxiliary locking structure only occurs after the complete failure of the morse taper connection, and the stability of the morse taper connection can be continuously maintained and enhanced before the failure of the morse taper connection.

It should be understood that while preferred embodiments have been illustrated and described, the invention is not limited to the precise embodiments described above, and that various modifications and changes can be made by one skilled in the art without departing from the spirit and scope of the appended claims. Therefore, it should be noted that various modifications and variations cannot be considered as beyond the technical spirit and scope of the invention.