Hip joint prosthesis

Abstract

The application provides a hip joint prosthesis, which comprises: a acetabular cup, the acetabular cup has a containing cavity, the acetabular cup is provided with a first magnetic part and a limiting ring groove, the limiting ring groove is arranged in communication with the containing cavity; a ball head, the ball head is rotatably arranged in the containing cavity; a snap ring, the snap ring is sleeved outside the equator part of the ball head, and the ball head can swing relative to the snap ring; the snap ring is provided with a second magnetic part, the second magnetic part is magnetically attracted and matched with the first magnetic part, so that the ball head is connected with the acetabular cup, at least part of the snap ring swings with the ball head in the limiting ring groove, and the snap ring can be limitedly matched with the side wall of the limiting ring groove; and a femoral stem, which is fixedly connected with the ball head. The technical scheme of the application effectively solves the problem of insufficient activity range of the hip joint prosthesis in the related art, which affects the joint flexibility.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a hip joint prosthesis. Background Technology

[0002] Hip replacement surgery is a common treatment for hip joint diseases, especially for severe osteoarthritis, hip fractures, or congenital hip dysplasia. It can significantly improve patients' quality of life and restore their ability to walk and perform daily activities.

[0003] However, hip prostheses in these technologies have certain limitations, primarily in their restricted range of motion. To ensure stability and avoid the risk of early loosening and dislocation, hip prostheses in these technologies typically restrict the natural range of motion of the joint. A hip prosthesis consists of an acetabular cup, a ball head, and a femoral stem. The ball head is fixedly connected to the femoral stem and is rotatably positioned within the acetabular cup. Furthermore, the acetabular cup needs to cover most of the ball head to ensure a stable connection, but the femoral stem can easily interfere with the edge of the acetabular cup during rotation, thus limiting its range of motion. Therefore, in complex movements such as deep flexion, abduction, and rotation of the hip joint, the structure and connection method of the hip prosthesis can lead to insufficient range of motion, directly affecting the patient's postoperative joint flexibility and motor coordination.

[0004] Thus, the range of motion of hip joint prostheses in related technologies is insufficient, affecting joint flexibility. Summary of the Invention

[0005] The main objective of this invention is to provide a hip joint prosthesis to solve the problem of insufficient range of motion in related technologies, which affects joint flexibility.

[0006] To achieve the above objectives, according to one aspect of the present invention, a hip joint prosthesis is provided, comprising: an acetabular cup having a receiving cavity, a first magnetic element and a limiting ring groove disposed on the acetabular cup, the limiting ring groove being connected to the receiving cavity; a ball head rotatably disposed within the receiving cavity; a retaining ring sleeved outside the equatorial portion of the ball head, and the ball head being able to swing relative to the retaining ring, the retaining ring being provided with a second magnetic element, the second magnetic element magnetically engaging with the first magnetic element to connect the ball head to the acetabular cup, at least a portion of the retaining ring swinging with the ball head within the limiting ring groove, the retaining ring being able to be limited and engaged with the side wall of the limiting ring groove; and a femoral stem fixedly connected to the ball head.

[0007] Furthermore, the first magnetic element is a first magnetic ring, which surrounds the circumferential outer side of the limiting ring groove, and the inner ring surface of the first magnetic ring forms at least part of the bottom wall of the limiting ring groove.

[0008] Furthermore, the limiting ring groove penetrates the surface of the acetabular cup toward the femoral stem.

[0009] Furthermore, the second magnetic element is a second magnetic ring, the outer ring surface of the second magnetic ring forming at least a portion of the outer ring surface of the retaining ring; the inner surface of the first magnetic ring extends along its axial direction to have a first length, and the outer surface of the second magnetic ring extends along its axial direction to have a second length, the first length being greater than the second length.

[0010] Furthermore, the relationship between the first length L1 and the second length L2 satisfies: 2.0≤L1 / L2≤3.5.

[0011] Furthermore, the retaining ring has a first ring segment and a second ring segment connected along its axial direction. The first ring segment is located on the side of the retaining ring closer to the femoral stem. The inner diameter of the first ring segment is smaller than the outer diameter of the ball head. The inner diameter of the second ring segment is greater than or equal to the outer diameter of the ball head. The first ring segment is in contact with the ball head.

[0012] Furthermore, the acetabular cup includes an outer acetabular cup and an acetabular liner disposed within the outer acetabular cup. A limiting annular groove is disposed on the acetabular liner, and the outer acetabular cup is provided with a porous structure that penetrates the outer surface of the outer acetabular cup.

[0013] Furthermore, the hip joint prosthesis also includes a locking structure disposed between the femoral stem and the ball head. The locking structure includes a pin, a spring, and two inserts. The two inserts are respectively disposed at both ends of the spring and are movably disposed on the femoral stem. Each insert has a socket, and the ball head has a corresponding slot. The pin is movably disposed between the femoral stem and the ball head to have an insertion state and a clearance state. When the pin is in the insertion state, the pin is inserted into the two sockets, so that the spring is compressed and the insert is retracted into the femoral stem. When the pin is in the clearance state, the pin is separated from the insert, and the insert is inserted into the slot under the action of the spring.

[0014] Furthermore, the locking structure also includes a buckle disposed inside the ball head, and the pin is provided with a snap-fit ​​hole that engages with the buckle. When the pin is in the avoidance state, the buckle extends into the snap-fit ​​hole to engage with the pin. The buckle includes at least two claws spaced apart, and the free end of each claw is provided with a snap flap that can engage with the pin stop.

[0015] Furthermore, the pin is a third magnetic element; and / or, a conical mounting groove is provided on the ball head, the conical mounting groove forming an opening on the surface of the ball head, the diameter of the conical mounting groove gradually decreasing along the direction from the opening to the bottom wall of the conical mounting groove; a conical handle is provided on the femoral stem, the diameter of the conical handle gradually decreasing along the direction from near the femoral stem to far away from the femoral stem, the conical handle being installed in the conical mounting groove; the spring and the insert are movably disposed in the conical handle, the buckle is disposed on the bottom wall of the conical mounting groove, and the pin is movably disposed in the conical mounting groove.

[0016] According to the technical solution of this invention, a hip joint prosthesis includes: an acetabular cup, a ball head, a clasp, and a femoral stem. The acetabular cup has a receiving cavity, and a first magnetic element and a limiting ring groove are provided on the acetabular cup, with the limiting ring groove communicating with the receiving cavity. The ball head is rotatably disposed within the receiving cavity. The clasp is sleeved outside the equatorial portion of the ball head, and the ball head can swing relative to the clasp. The clasp is provided with a second magnetic element, which magnetically engages with the first magnetic element to connect the ball head to the acetabular cup. At least a portion of the clasp swings with the ball head within the limiting ring groove, and the clasp can be limited and engaged with the side wall of the limiting ring groove. The femoral stem is fixedly connected to the ball head. Thus, by sleeved outside the equatorial portion of the ball head, the ball head can swing relative to the clasp, and the ball head will not dislodge from the clasp. The design of the retaining ring groove allows the retaining ring to swing relative to the acetabular cup, thereby increasing the range of motion of the ball joint connected to the retaining ring. Furthermore, the sidewall of the retaining ring groove limits the swing range of the retaining ring, ensuring it can swing within a suitable range relative to the acetabular cup and preventing the ball joint from dislodging. Additionally, the magnetic attraction between the first and second magnetic components creates traction between the retaining ring and the acetabular cup as the retaining ring swings relative to it, improving the connection stability between the hip joint prosthesis and further preventing the ball joint from dislodging. This magnetic attraction mechanism not only provides additional interaction force but also simulates the soft tissue restraint in a natural hip joint, thereby increasing the overall joint tension and reducing the likelihood of ball joint dislocation. Especially in elderly patients with soft tissue laxity in the hip joint, this method effectively compensates for the instability caused by soft tissue aging, ensuring the reliability of the hip joint prosthesis while increasing its range of motion. In this way, when the femoral stem rotates to the edge of the acetabular cup, the clasp can swing relative to the acetabular cup to further expand the swing range of the ball head connected to the clasp, thereby increasing the range of motion of the hip joint prosthesis. Therefore, the technical solution of this application effectively solves the problem of insufficient range of motion of hip joint prostheses in related technologies, which affects joint flexibility. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A three-dimensional structural schematic diagram of an embodiment of a hip joint prosthesis according to the present invention is shown;

[0019] Figure 2 It shows Figure 1 A cross-sectional view of a hip joint prosthesis;

[0020] Figure 3 It shows Figure 2 A magnified schematic diagram of a portion of a hip joint prosthesis;

[0021] Figure 4 It shows Figure 3 A magnified view of part A of the hip joint prosthesis;

[0022] Figure 5 It shows Figure 1 A partial sectional view of the ball head of the hip joint prosthesis.

[0023] The above figures include the following reference numerals:

[0024] 10. Acetate cup; 11. Receiving cavity; 12. Limiting ring groove; 13. First magnetic component; 14. Acetate outer cup; 141. Porous structure; 15. Acetate liner;

[0025] 20. Ball head; 21. Slot; 22. Conical mounting slot;

[0026] 30. Femoral stem; 31. Conical stem;

[0027] 40. Snap ring; 41. First ring segment; 42. Second ring segment; 43. Second magnetic component;

[0028] 51. Pin; 511. Snap-fit ​​hole; 52. Spring; 53. Insert block; 54. Snap fastener; 541. Claw; 542. Claw flap; 5421. Guide slope. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0032] In this embodiment, as Figures 1 to 4 As shown, the hip joint prosthesis includes: an acetabular cup 10, a ball head 20, a retaining ring 40, and a femoral stem 30. The acetabular cup 10 has a receiving cavity 11, and a first magnetic element 13 and a limiting ring groove 12 are provided on the acetabular cup 10. The limiting ring groove 12 is connected to the receiving cavity 11. The ball head 20 is rotatably disposed within the receiving cavity 11. The retaining ring 40 is sleeved on the equatorial portion of the ball head 20, and the ball head 20 can swing relative to the retaining ring 40. A second magnetic element 43 is provided on the retaining ring 40, and the second magnetic element 43 magnetically engages with the first magnetic element 13 to connect the ball head 20 to the acetabular cup 10. At least a portion of the retaining ring 40 swings with the ball head 20 within the limiting ring groove 12, and the retaining ring 40 can be limited and engaged with the side wall of the limiting ring groove 12. The femoral stem 30 is fixedly connected to the ball head 20.

[0033] In this way, by fitting the retaining ring 40 outside the equatorial portion of the ball head 20, the ball head 20 can swing relative to the retaining ring 40 without dislodging from it. The limiting ring groove 12 allows the retaining ring 40 space to swing relative to the acetabular cup 10, thereby increasing the range of motion of the ball head 20 connected to the retaining ring 40. Furthermore, the sidewall of the limiting ring groove 12 restricts the swing range of the retaining ring 40, allowing it to swing within a suitable range relative to the acetabular cup 10, preventing the ball head 20 from dislodging from the acetabular cup 10. Moreover, the magnetic attraction between the first magnetic element 13 and the second magnetic element 43 creates a traction force between the retaining ring 40 and the acetabular cup 10 when the retaining ring 40 swings relative to it, improving the connection stability between the hip joint prosthesis and further preventing the ball head 20 from dislodging from the acetabular cup 10. This magnetic attraction mechanism not only provides additional interaction force but also simulates the soft tissue restraint in a natural hip joint, thereby increasing the overall joint tension and reducing the likelihood of dislocation of the ball head 20. Especially in elderly patients with soft tissue laxity in the hip joint, this method effectively compensates for the instability caused by soft tissue aging, ensuring the reliability of the hip prosthesis while increasing its range of motion. Thus, when the femoral stem 30 rotates to the edge of the acetabular cup 10, the retaining ring 40 can swing relative to the acetabular cup 10, further expanding the swing range of the ball head 20 connected to the retaining ring 40, thereby increasing the range of motion of the hip prosthesis. Therefore, the technical solution of this embodiment effectively solves the problem of insufficient range of motion of hip prostheses in related technologies, which affects joint flexibility.

[0034] Furthermore, through the above-described configuration, the acetabular cup 10 can be stably connected to the ball head without needing to cover most of the ball head. In this embodiment, the acetabular cup 10 is the portion cut off by the equatorial plane of the hollow sphere, which has a center, and the surface passing through the center of the hollow sphere is the equatorial plane.

[0035] It should be noted that the clasp 40 is fitted outside the equatorial portion of the ball head 20, meaning that the ball head 20 has a center, and the surface passing through the center of the ball head 20 is the equatorial surface. Each equatorial surface forms an equator on the outer surface of the ball head. When the clasp 40 is fitted outside the ball head 20, the clasp 40 covers the outside of the equator.

[0036] like Figures 2 to 4As shown, the first magnetic element 13 is a first magnetic ring, which surrounds the circumferential outer side of the limiting ring groove 12, and the inner ring surface of the first magnetic ring forms at least part of the bottom wall of the limiting ring groove 12. By designing the first magnetic element 13 as a first magnetic ring and surrounding the circumferential outer side of the limiting ring groove 12, the uniform distribution of the magnetism of the first magnetic element 13 on the acetabular cup 10 can be ensured, making the magnetic attraction force on the retaining ring 40 more uniform. In addition, the inner ring surface of the first magnetic ring, as the bottom wall of the limiting ring groove 12, can better cooperate with the second magnetic element 43, ensuring a larger magnetic attraction force and further reducing the possibility of the ball head 20 and the retaining ring 40 dislodging from the acetabular cup 10.

[0037] like Figures 2 to 4 As shown, the limiting ring groove 12 penetrates the surface of the acetabular cup 10 facing the femoral stem 30. Thus, when the range of motion of the femoral stem 30 is small, the magnetic attraction between the first magnetic element 13 and the second magnetic element 43 is large, causing the edge of the retaining ring 40 to protrude from the surface of the acetabular cup 10 facing the femoral stem 30, facilitating the connection between the ball head 20 and the acetabular cup 10 via the retaining ring 40. When the range of motion of the femoral stem 30 is large, the retaining ring 40 overcomes the magnetic attraction between the first magnetic element 13 and the second magnetic element 43, causing the retaining ring 40 to swing. This allows a section of the retaining ring 40 corresponding to the direction of movement of the femoral stem 30 to retract into the limiting ring groove 12 for clearance, thereby expanding the range of motion of the femoral stem 30 relative to the acetabular cup 10 and increasing the range of motion of the hip joint prosthesis.

[0038] In this embodiment, when the range of motion of the femoral stem 30 is small, or when the femoral stem 30 is in its natural state, the retaining ring 40 protrudes from the limiting ring groove 12 and from the surface of the acetabular cup 10 facing the femoral stem 30. When the range of motion of the femoral stem 30 is large, part of the retaining ring 40 can retract into the acetabular cup 10 to avoid obstruction, thereby reducing the restriction of the retaining ring 40 or the acetabular cup 10 on the range of motion of the ball head 20 and the femoral stem 30, thus improving the range of motion of the hip joint prosthesis.

[0039] like Figures 2 to 4As shown, the second magnetic element 43 is a second magnetic ring, and the outer ring surface of the second magnetic ring forms at least a portion of the outer ring surface of the retaining ring 40. By designing the second magnetic element 43 as a second magnetic ring and surrounding the circumferential outer side of the retaining ring 40, the uniform distribution of the magnetism of the second magnetic element 43 on the retaining ring 40 can be ensured, making the magnetic attraction force on the acetabular cup 10 more uniform. In addition, the outer ring surface of the second magnetic ring, as the outer ring surface of the retaining ring 40, can better magnetically engage with the first magnetic element 13, ensuring a larger magnetic attraction force and further reducing the possibility of the ball head 20 and the retaining ring 40 dislodging from the acetabular cup 10. The inner surface of the first magnetic ring extends along its axial direction to have a first length, and the outer surface of the second magnetic ring extends along its axial direction to have a second length, the first length being greater than the second length. The first length of the first magnetic ring is greater than the second length of the second magnetic ring. This length difference helps maintain the continuity and stability of the magnetic force in different directions, so that the retaining ring 40 can continue to be attracted by the magnetic force of the first magnetic element 13 when it swings within the limiting ring groove 12, further improving the connection reliability between the acetabular cup 10 and the retaining ring 40. Specifically, the inner surface of the first magnetic ring and the outer surface of the second magnetic ring are in contact.

[0040] Furthermore, the relationship between the first length L1 and the second length L2 satisfies: 2.0 ≤ L1 / L2 ≤ 3.5. By controlling the ratio of the first length L1 to the second length L2 between 2.0 and 3.5, this ratio can ensure sufficient magnetic connection strength without making the size of the first magnetic ring too large, resulting in an excessively large limiting ring groove 12, thus ensuring the structural compactness of the hip joint prosthesis.

[0041] Preferably, L1 / L2 is 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4 or 3.5.

[0042] like Figures 2 to 4 As shown, the retaining ring 40 has a first ring segment 41 and a second ring segment 42 connected along its axial direction. The first ring segment 41 is located on the side of the retaining ring 40 closer to the femoral stem 30. The inner diameter of the first ring segment 41 is smaller than the outer diameter of the ball head 20, and the inner diameter of the second ring segment 42 is greater than or equal to the outer diameter of the ball head 20. The first ring segment 41 is in contact with the ball head 20. In this way, the inner diameter of the first ring segment 41 is smaller than the outer diameter of the ball head 20, forming a physical barrier and preventing the ball head 20 from dislodging from the retaining ring 40 from the side of the first ring segment 41, thereby improving the connection reliability between the retaining ring 40 and the ball head 20. The inner diameter of the second ring segment 42 is greater than or equal to the outer diameter of the ball head 20, allowing the equatorial plane of the ball head 20 to swing within the second ring segment 42, thus facilitating the swing of the ball head 20 relative to the retaining ring 40.

[0043] Furthermore, the above-mentioned configuration facilitates the assembly of the hip joint prosthesis. The ball head 20 is inserted into the retaining ring 40 from the second ring segment 42 end, allowing a portion of the outer wall surface of the ball head 20 to engage with the stop of the first ring segment 41, preventing the ball head 20 from dislodging from the first ring segment 41 of the retaining ring 40. The ball head 20 is then connected to the femoral stem 30. The retaining ring 40 is then placed within the limiting ring groove 12 of the acetabular cup 10, allowing the first magnetic element 13 and the second magnetic element 43 to magnetically engage, thereby completing the connection between the retaining ring 40 and the acetabular cup 10.

[0044] In this embodiment, the inner diameter of the second ring segment 42 is equal to the outer diameter of the ball head 20, and both the first ring segment 41 and the second ring segment 42 are in contact with the ball head 20.

[0045] In other embodiments, the inner diameter of the first ring segment 41 is smaller than the outer diameter of the ball head 20, the inner diameter of the second ring segment 42 is larger than the outer diameter of the ball head 20, and there is a connecting ring segment between the first ring segment 41 and the second ring segment 42. The diameter of the connecting ring segment is equal to the outer diameter of the ball head 20, and both the first ring segment 41 and the connecting ring segment are in contact with the ball head 20.

[0046] like Figures 2 to 4 As shown, the acetabular cup 10 includes an outer acetabular cup 14 and an acetabular liner 15 disposed within the outer acetabular cup 14. A limiting annular groove 12 is disposed on the acetabular liner 15. The outer acetabular cup 14 has a porous structure 141 that penetrates the outer surface of the outer acetabular cup 14. The porous structure 141 on the outer acetabular cup 14 can promote the ingrowth of surrounding bone tissue and enhance the biocompatibility between the hip joint prosthesis and human bone. This design is particularly suitable for the elderly population, whose bone density is lower and healing ability is weakened. The porous structure 141 can provide a better osseointegration environment, shorten the rehabilitation period, and reduce the risk of secondary surgery. At the same time, the acetabular liner 15 can reduce the contact between the body's own bone and metal, reduce wear on the body's own bone, and also extend the service life of the hip joint prosthesis.

[0047] like Figure 5As shown, the hip joint prosthesis also includes a locking structure disposed between the femoral stem 30 and the ball head 20. The locking structure includes a pin 51, a spring 52, and a locking block 53. There are two locking blocks 53, each disposed at one end of the spring 52 and movably mounted on the femoral stem 30. Each locking block 53 has a recessed hole, and the ball head 20 has a corresponding slot 21. The pin 51 is movably disposed between the femoral stem 30 and the ball head 20 to have an inserted state and a recessed state. When the pin 51 is in the inserted state, it is inserted into the two recessed holes, compressing the spring 52 and retracting the locking block 53 into the femoral stem 30. When the pin 51 is in the recessed state, it separates from the locking block 53, and the locking block 53 is inserted into the slot 21 under the action of the spring 52. In this way, before the ball head 20 is installed onto the femoral stem 30, the pin 51 is in the inserted state, and the insert block 53 retracts into the femoral stem 30, facilitating the installation of the ball head 20 onto the femoral stem 30. After the ball head 20 is installed onto the femoral stem 30, the pin 51 switches to the clearance state, allowing the insert block 53 to be inserted into the slot 21 under the action of the spring 52. The insert block 53 connects the ball head 20 and the femoral stem 30, reducing relative movement and rotation between the ball head 20 and the femoral stem 30, and achieving a reliable connection between them. The locking structure enables quick and reliable fixation between the ball head 20 and the femoral stem 30. This mechanism not only simplifies the assembly process of the ball head 20 and the femoral stem 30, but also reduces the possibility of relative movement between the ball head 20 and the femoral stem 30 during use, thereby reducing the possibility of wear and debris generation between the ball head 20 and the femoral stem 30, and improving safety during use.

[0048] like Figure 5As shown, the locking structure also includes a latch 54 disposed within the ball head 20. The pin 51 has a latching hole 511 that engages with the latch 54. When the pin 51 is in the clearance position, the latch 54 extends into the latching hole 511 to engage with the pin 51. The latch 54 includes at least two spaced-apart claws 541, each claw 541 having a latching flap 542 at its free end that engages with the pin 51. Thus, the latch 54 keeps the pin 51 in the clearance position, reducing the possibility of the pin 51 moving between the ball head 20 and the femoral stem 30 after the ball head 20 and femoral stem 30 are connected by the insert block 53, thereby improving the safety of the hip joint prosthesis. Furthermore, the latch 54 has a simple structure, allowing the pin 51 to engage with the latch 54 without additional operation. When the pin 51 approaches the latch 54, the free ends of the claws 541 abut against the wall of the engaging holes 511 on the pin 51, so that the free ends of at least two claws 541 move closer to each other, allowing the engaging holes 511 to pass over the latch flaps 542. Once the engaging holes 511 have passed over the latch flaps 542, the free ends of at least two claws 541 move away from each other and return to their initial state. At this point, the latch flaps 542 engage with the stop of the pin 51, allowing the pin 51 to be secured by the latch 54. The latch 54 has a simple structure, is easy to manufacture, and is convenient to use.

[0049] In this embodiment, a guide slope 5421 is provided at the end of the latch 542 facing the femoral stem 30. The thickness of the guide slope 5421 gradually decreases in the direction away from the femoral stem 30 and closer to the femoral stem 30. When the pin 51 is in the inserted state, the edge of the latching hole 511 on the pin 51 contacts the guide slope 5421 to facilitate smooth subsequent engagement between the latching hole 511 on the pin 51 and the buckle 54.

[0050] like Figure 5As shown, the pin 51 is a third magnetic component. Thus, by using a magnetic attractor on the outside of the ball head 20 and femoral stem 30, the pin 51 can be driven to switch from an inserted state to an abduction state, enabling the pin 51 to switch from an inserted state to an abduction state without requiring an additional drive source. The ball head 20 is provided with a tapered mounting groove 22, which forms an opening on its surface. The diameter of the tapered mounting groove 22 gradually decreases from the opening to the bottom wall of the tapered mounting groove 22. The femoral stem 30 is provided with a tapered stem 31, the diameter of which gradually decreases from near to far from the femoral stem 30. The tapered stem 31 is installed within the tapered mounting groove 22. The spring 52 and the insert block 53 are movably disposed within the tapered stem 31, and the latch 54 is disposed on the bottom wall of the tapered mounting groove 22. The pin 51 is movably disposed within the tapered mounting groove 22. The tapered mounting groove 22 on the ball head 20 cooperates with the tapered stem 31 on the femoral stem 30. This structure can provide better positioning accuracy, further ensure a firm connection between the femoral stem 30 and the ball head 20, and reduce the risk of hip joint prosthesis loosening.

[0051] In this embodiment, after the tapered handle 31 is inserted into the tapered mounting groove 22 to a preset depth, the pin 51 is switched from the insertion state to the avoidance state so that the insert 53 can tend to extend out of the femoral stem 30. At this time, by driving the relative rotation between the ball head 20 and the femoral stem 30, the insert 53 can be aligned with the slot 21 to realize the connection between the ball head 20 and the femoral stem 30.

[0052] In other embodiments, the pin 51 is a third magnetic element. Alternatively, the ball head 20 is provided with a conical mounting groove 22, which forms an opening on the surface of the ball head 20, and the diameter of the conical mounting groove 22 gradually decreases along the direction from the opening to the bottom wall of the conical mounting groove 22; the femoral stem 30 is provided with a conical handle 31, the diameter of the conical handle 31 gradually decreases along the direction from near the femoral stem 30 to far away from the femoral stem 30, and the conical handle 31 is installed in the conical mounting groove 22; the spring 52 and the insert block 53 are movably disposed in the conical handle 31, the buckle 54 is disposed on the bottom wall of the conical mounting groove 22, and the pin 51 is movably disposed in the conical mounting groove 22.

[0053] The inventors discovered that in related technologies, the femoral stem 30 and ball head 20 of the hip joint prosthesis are clamped together using a tapered fitting. However, as the metal fatigues and wears down, the tapered fitting fails, causing friction between the ball head and the femoral stem. In the field of artificial joints, metal-to-metal contact is not an ideal friction surface, which can generate metal debris and increase the risk of infection. Furthermore, tapered fitting failure also increases the risk of joint dislocation.

[0054] The locking structure in this embodiment reduces the relative rotation between the ball head 20 and the femoral stem 30 after implantation, reducing friction and debris generation, thereby lowering the risk of infection.

[0055] In the description of this invention, it should be understood that "a plurality of" means two or more. Directional terms such as "front, back, up, down, left, right," "horizontal, vertical, perpendicular, horizontal," and "top, bottom" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0056] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0057] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hip joint prosthesis, characterized in that, include: An acetabular cup (10) has a receiving cavity (11). The acetabular cup (10) is provided with a first magnetic element (13) and a limiting ring groove (12). The limiting ring groove (12) is connected to the receiving cavity (11). A ball head (20) is rotatably disposed within the receiving cavity (11); A retaining ring (40) is sleeved outside the equatorial portion of the ball head (20), and the ball head (20) can swing relative to the retaining ring (40). A second magnetic element (43) is provided on the retaining ring (40), and the second magnetic element (43) is magnetically attracted to the first magnetic element (13) so that the ball head (20) is connected to the acetabular cup (10). At least part of the retaining ring (40) swings with the ball head (20) in the limiting ring groove (12), and the retaining ring (40) can be limited and engaged with the side wall of the limiting ring groove (12). The femoral stem (30) is fixedly connected to the ball head (20); The retaining ring (40) has a first ring segment (41) and a second ring segment (42) connected along its axial direction. The first ring segment (41) is located on the side of the retaining ring (40) near the femoral stem (30). The inner diameter of the first ring segment (41) is smaller than the outer diameter of the ball head (20). The inner diameter of the second ring segment (42) is greater than or equal to the outer diameter of the ball head (20). The first ring segment (41) is in contact with the ball head (20).

2. The hip joint prosthesis according to claim 1, characterized in that, The first magnetic element (13) is a first magnetic ring, which surrounds the circumferential outer side of the limiting ring groove (12), and the inner ring surface of the first magnetic ring forms at least part of the bottom wall of the limiting ring groove (12).

3. The hip joint prosthesis according to claim 2, characterized in that, The limiting annular groove (12) penetrates the surface of the acetabular cup (10) facing the femoral stem (30).

4. The hip joint prosthesis according to claim 2, characterized in that, The second magnetic element (43) is a second magnetic ring, the outer ring surface of the second magnetic ring forms at least a portion of the outer ring surface of the retaining ring (40); the inner surface of the first magnetic ring extends along its axial direction to have a first length, the outer surface of the second magnetic ring extends along its axial direction to have a second length, the first length being greater than the second length.

5. The hip joint prosthesis according to claim 4, characterized in that, The relationship between the first length L1 and the second length L2 satisfies: 2.0≤L1 / L2≤3.

5.

6. The hip joint prosthesis according to claim 1, characterized in that, The acetabular cup (10) includes an outer acetabular cup (14) and an acetabular liner (15) disposed within the outer acetabular cup (14). The limiting annular groove (12) is disposed on the acetabular liner (15). The outer acetabular cup (14) is provided with a porous structure (141) that penetrates the outer surface of the outer acetabular cup (14).

7. The hip joint prosthesis according to claim 1, characterized in that, The hip joint prosthesis also includes a locking structure disposed between the femoral stem (30) and the ball head (20). The locking structure includes a pin (51), a spring (52), and a plug (53). There are two plugs (53), which are respectively disposed at both ends of the spring (52) and are movably disposed on the femoral stem (30). Both plugs (53) are provided with insertion holes. The ball head (20) is provided with a slot (21) corresponding to the plug (53). The pin (51) is movably disposed between the femoral stem (30) and the ball head (20) to have an insertion state and a clearance state; when the pin (51) is in the insertion state, the pin (51) is inserted into the two holes so that the spring (52) is compressed and the plug (53) is retracted into the femoral stem (30); when the pin (51) is in the clearance state, the pin (51) is separated from the plug (53) and the plug (53) is inserted into the slot (21) under the action of the spring (52).

8. The hip joint prosthesis according to claim 7, characterized in that, The locking structure further includes a buckle (54) disposed in the ball head (20). The pin (51) is provided with a snap-fit ​​hole (511) that engages with the buckle (54). When the pin (51) is in the avoidance state, the buckle (54) extends into the snap-fit ​​hole (511) so that the buckle (54) engages with the pin (51). The buckle (54) includes at least two claws (541) spaced apart. The free end of each claw (541) is provided with a clip (542) that can engage with the stop of the pin (51).

9. The hip joint prosthesis according to claim 8, characterized in that, The pin (51) is a third magnetic element; and / or, The ball head (20) is provided with a conical mounting groove (22), which forms an opening on the surface of the ball head (20). The diameter of the conical mounting groove (22) gradually decreases along the direction from the opening to the bottom wall of the conical mounting groove (22). The femoral stem (30) is provided with a conical handle (31), which gradually decreases along the direction from near the femoral stem (30) to away from the femoral stem (30). The conical handle (31) is installed in the conical mounting groove (22). The spring (52) and the insert (53) are movably disposed in the conical handle (31). The buckle (54) is disposed on the bottom wall of the conical mounting groove (22). The pin (51) is movably disposed in the conical mounting groove (22).

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