Adjustable eccentric knee joint center defect filling system

Abstract

The present application relates to the technical field of medical devices, and more particularly to an adjustable eccentric knee joint center defect filling system, comprising an eccentric conversion joint, a center pad and a prosthesis, the prosthesis is provided with a prosthesis connecting column center hole, the center pad is provided with a center pad connecting hole, the eccentric conversion joint is provided with a prosthesis connecting head and a center pad connecting head, the prosthesis connecting head and the center pad connecting head are arranged opposite and eccentrically, the prosthesis connecting head is inserted into the prosthesis connecting column center hole, and the center pad connecting head is inserted into the center pad connecting hole. The system provided by the present application can effectively solve the problem of poor bone coverage caused by the eccentricity of the marrow cavity and the prosthesis, improve the comfort of the patient, and has good overall support, can prevent collapse after repair of the bone defect, and can ensure the initial stability and be beneficial to the later bone growth.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an adjustable eccentric knee joint center defect filling system. Background Technology

[0002] As the number of people undergoing total knee replacement surgery continues to rise, the number of total knee revision surgeries is also increasing.

[0003] Total knee revision surgery results in varying degrees of bone defects on the distal femoral and metaphysis, and the proximal tibia and metaphysis. Common methods include bone cement filling and bone filler blocks to ensure adequate support between the prosthesis and bone. While filler blocks offer better results than bone cement, current bone filler block systems have a drawback: due to misalignment between the medullary cavity and the prosthesis, or issues with filler block design and prosthesis manipulation, the prosthesis may not achieve optimal bone coverage, causing discomfort for the patient. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an adjustable eccentric knee joint center defect filling system, which can effectively solve the problem of poor bone coverage caused by the eccentricity of the medullary cavity and the prosthesis, and improve patient comfort.

[0005] This invention is achieved through the following scheme: An adjustable eccentric knee joint center defect filling system includes an eccentric conversion joint, a central pad, and a prosthesis. The prosthesis has a central hole for a prosthesis connecting post, and the central pad has a central pad connecting hole. The eccentric conversion joint has a prosthesis connector and a central pad connector. The prosthesis connector and the central pad connector are opposite to each other and eccentrically positioned. The prosthesis connector is inserted into the central hole for the prosthesis connecting post, and the central pad connector is inserted into the central pad connecting hole.

[0006] Preferably, the central pad has a frustum-shaped structure with a larger bottom diameter and a smaller top diameter.

[0007] Furthermore, the bottom of the central pad has a clearance opening, and the top of the clearance opening has a step, with the central pad connection hole located above the step.

[0008] Preferably, the connecting hole of the central pad is an arc-shaped structure with a concave center.

[0009] Furthermore, both the central pad and the prosthesis sidewall are provided with top screw mounting holes. The end of the central pad connector is provided with a central pad top screw mounting part, and the end of the prosthesis connector is provided with a prosthesis top screw mounting part. Both the central pad top screw mounting part and the prosthesis top screw mounting part are provided with arc-shaped concave outer sidewalls. The central pad and the prosthesis are fixed to the eccentric conversion joint at the corresponding top screw mounting holes by top screws.

[0010] Furthermore, both the prosthesis connector and the central pad connector are frustoconical structures. The central hole of the prosthesis connector is matched with the prosthesis connector, the lower part of the central pad connector hole is matched with the central pad connector, and the upper part of the central pad connector hole is matched with the shape of the extension rod inserted into the bone shaft medullary cavity.

[0011] Furthermore, both the prosthesis connector and the central pad connector are provided with connector screw mounting holes at their ends, and the prosthesis is provided with prosthesis screw mounting holes.

[0012] Preferably, the outer surface of the central pad has a porous trabecular structure.

[0013] Preferably, the prosthesis is a femoral prosthesis or a tibial prosthesis.

[0014] Preferably, the center pad is made using additive manufacturing technology.

[0015] Beneficial effects of the invention: The adjustable eccentric knee joint center defect filling system provided by this invention, by setting an eccentric conversion joint and a central pad, with the prosthesis connector of the eccentric conversion joint and the central pad connector being opposite and eccentrically positioned, the prosthesis connector being inserted into the central hole of the prosthesis connector post, and the central pad connector being inserted into the central pad connector hole, can effectively solve the problem of poor bone coverage caused by the eccentricity of the medullary cavity and the prosthesis, improve patient comfort, and provide good overall support, preventing collapse of the bone defect after repair. Furthermore, since the central pad, the prosthesis, and the eccentric conversion joint are all fixed with set screws or screws, relative rotation between components can be prevented, thus achieving better initial stability. In addition, the outer surface of the central pad has a porous trabecular bone structure, which can improve overall strength and achieve biological fixation without the need for bone cement fixation, effectively preventing bone cement from seeping into the trabecular bone structure and affecting bone ingrowth. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the eccentric adapter of the present invention.

[0017] Figure 2 This is a schematic diagram of the central pad structure of the present invention.

[0018] Figure 3 This is a schematic diagram of the assembly structure of the eccentric conversion joint, the central pad, and the femoral prosthesis of the present invention.

[0019] Figure 4 This is a schematic diagram of the assembly structure of the eccentric conversion joint, the central pad, and the tibial prosthesis of the present invention.

[0020] In the diagram: 1. Eccentric adapter; 11. Prosthesis connector; 12. Central pad connector; 13. Central pad top screw mounting part; 14. Prosthesis top screw mounting part; 15. Connector screw mounting hole; 16. Prosthesis screw mounting hole; 2. Central pad; 21. Central pad connecting hole; 22. Step; 23. Relief opening; 24. Top screw mounting hole; 3. Femoral prosthesis; 31. Central hole of prosthesis connecting post; 4. Tibial prosthesis. Detailed Implementation

[0021] The adjustable eccentric knee joint center defect filling system includes an eccentric adapter 1, a central pad 2, and a prosthesis. A schematic diagram of the eccentric adapter is shown below. Figure 1 As shown in the diagram, the central pad block structure is as follows: Figure 2 As shown in the diagram, the eccentric adapter joint, the central pad, and the femoral prosthesis 3 assembly structure are illustrated in the figure below. Figure 3 As shown in the diagram, the eccentric adapter joint, the central pad, and the tibial prosthesis 4 are assembled in a schematic diagram. Figure 4 As shown, the prosthesis has a central hole 31 for the prosthesis connecting post, the central pad has a central pad connecting hole 21, and the eccentric conversion joint has a prosthesis connecting head 11 and a central pad connecting head 12. The prosthesis connecting head and the central pad connecting head are opposite to each other and are eccentrically arranged. The prosthesis connecting head is inserted into the central hole of the prosthesis connecting post, and the central pad connecting head is inserted into the central pad connecting hole.

[0022] Specifically, the relative eccentricity between the prosthesis connector and the central pad connector can be set as needed, or the eccentricity can be zero, i.e., no eccentricity.

[0023] During the surgery, the other end of the extension rod (not shown) inserted into the bone shaft medullary cavity is inserted into the top of the central pad connection hole, thereby connecting the adjustable eccentric knee joint central defect filling system to the bone shaft medullary cavity. Due to the eccentric conversion joint and central pad, the prosthesis connector of the eccentric conversion joint and the central pad connector are opposite and eccentrically positioned. The prosthesis connector is inserted into the central hole of the prosthesis connector post, and the central pad connector is inserted into the central pad connection hole. This effectively solves the problem of poor bone coverage caused by the eccentricity between the bone shaft medullary cavity and the prosthesis, improves patient comfort, and provides good overall support, preventing collapse after bone defect repair.

[0024] Preferably, the central pad has a frustum-shaped structure with a large bottom diameter and a small top diameter, which can form an anatomically shaped central pad, making the structure more in line with the human skeletal structure. Furthermore, the rounded edges can reduce soft tissue pain after implantation. The frustum-shaped structure conforms to the shape of the bone defect area at the end of the knee joint, which can fill the defect area and effectively prevent the central pad of the knee joint from sinking again, thus increasing the overall stability.

[0025] Furthermore, the bottom of the central pad is provided with a clearance opening 23, and the top of the clearance opening is provided with a step 22. The central pad connection hole is located above the step. The clearance opening at the bottom of the central pad can prevent the central pad from colliding with the patellar trochlear area of ​​the prosthesis. The step at the top of the clearance opening and the central pad connection hole located above the step can provide axial rotation space for the eccentric conversion joint.

[0026] Preferably, the central pad connection hole has an arc-shaped structure with a concave center, which facilitates the insertion of the central pad connector of the eccentric conversion joint into the lower part of the central pad connection hole, and the other end of the extension rod inserted into the bone marrow cavity is inserted into the upper part of the central pad connection hole. The shapes of the extension rod inserted into the bone marrow cavity and the central pad connector of the eccentric conversion joint are respectively matched to form a good tight fit.

[0027] Furthermore, both the central pad and the prosthesis sidewall are provided with top screw mounting holes 24. The end of the central pad connector is provided with a central pad top screw mounting part 13, and the end of the prosthesis connector is provided with a prosthesis top screw mounting part 14. Both the central pad top screw mounting part and the prosthesis top screw mounting part are provided with an arc-shaped concave outer wall. The central pad and the prosthesis are fixed to the eccentric conversion joint at the corresponding top screw mounting holes by top screws. This allows the top screw to be installed at the top screw mounting holes, with the top screw pressing against the arc-shaped concave part of the outer wall of the prosthesis top screw mounting part or the central pad top screw mounting part, preventing relative rotation between the eccentric conversion joint and the central pad or between the eccentric conversion joint and the prosthesis, thereby enabling the adjustable eccentric knee joint central defect filling system to obtain better initial stability.

[0028] Furthermore, both the prosthesis connector and the center pad connector are frustoconical structures. The center hole of the prosthesis connector is matched with the prosthesis connector, the lower part of the center pad connector hole is matched with the center pad connector, and the upper part of the center pad connector hole is matched with the shape of the extension rod. This allows for a better and tighter fit between the eccentric adapter, the center pad, and the prosthesis.

[0029] Furthermore, both the prosthesis connector and the central pad connector are provided with connector screw mounting holes 15, and the prosthesis is provided with prosthesis screw mounting holes 16, which facilitates the connection between the prosthesis and the femoral prosthesis or the tibial prosthesis by screws.

[0030] Preferably, the outer surface of the central pad has a porous trabecular bone structure, which can improve the overall strength and achieve biological fixation without the need for bone cement fixation, effectively preventing bone cement from seeping into the trabecular bone structure and affecting bone ingrowth.

[0031] Preferably, the prosthesis is a femoral prosthesis or a tibial prosthesis, and the eccentric conversion joint and central pad can be adapted to both femoral and tibial prostheses.

[0032] Preferably, the center pad is made using additive manufacturing technology, which is convenient, quick, and low-cost.

[0033] In summary, the adjustable eccentric knee joint center defect filling system proposed in this invention can effectively solve the problem of poor bone coverage caused by the eccentricity of the medullary cavity and the prosthesis, improve patient comfort, provide good overall support, prevent collapse of the bone defect after repair, ensure initial stability, and promote subsequent bone growth.

[0034] 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. An adjustable eccentric knee joint center defect filling system, characterized in that: The device includes an eccentric adapter, a central pad, and a prosthesis. The prosthesis has a central hole for a prosthesis connecting post, and the central pad has a central pad connecting hole. The eccentric adapter has a prosthesis connector and a central pad connector. The prosthesis connector and the central pad connector are opposite to each other and eccentrically positioned. The prosthesis connector is inserted into the central hole of the prosthesis connecting post, and the central pad connector is inserted into the central pad connecting hole. The central pad has a frustum-shaped structure with a larger bottom diameter and a smaller top diameter. The bottom of the central pad has a clearance opening, and the top of the clearance opening has a step. The central pad connecting hole is located above the step. Each prosthesis has a top wire mounting hole on its sidewall. The end of the central pad connector has a central pad top wire mounting part, and the end of the prosthesis connector has a prosthesis top wire mounting part. Both the central pad top wire mounting part and the prosthesis top wire mounting part have an arc-shaped concave outer sidewall. The central pad and the prosthesis are fixed to the eccentric conversion joint at the corresponding top wire mounting holes by top wires. Both the prosthesis connector and the central pad connector are frustoconical structures. The central hole of the prosthesis connecting post matches the prosthesis connector. The lower part of the central pad connecting hole matches the central pad connector. The upper part of the central pad connecting hole matches the shape of the extension rod inserted into the bone shaft medullary cavity.

2. The adjustable eccentric knee joint center defect filling system according to claim 1, characterized in that: The connecting hole of the central pad is an arc-shaped structure with a concave center.

3. The adjustable eccentric knee joint center defect filling system according to claim 1, characterized in that: Both the prosthesis connector and the central pad connector are provided with connector screw mounting holes at their ends, and the prosthesis is provided with prosthesis screw mounting holes.

4. The adjustable eccentric knee joint center defect filling system according to claim 1, characterized in that: The outer surface of the central pad has a porous trabecular structure.

5. The adjustable eccentric knee joint center defect filling system according to claim 1, characterized in that: The prosthesis is either a femoral prosthesis or a tibial prosthesis.

6. The adjustable eccentric knee joint center defect filling system according to claim 1, characterized in that: The central pad is manufactured using additive manufacturing technology.

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