Adjustable eccentric knee joint center defect filling system

Abstract

The invention relates to the technical field of medical instruments, in particular to an adjustable eccentric knee joint center defect filling system which comprises an eccentric conversion connector, a center cushion block and a prosthesis, the prosthesis is provided with a prosthesis connecting column center hole, the center cushion block is provided with a center cushion block connecting hole, and the eccentric conversion connector is provided with a prosthesis connector and a center cushion block connector. The prosthesis connector and the center cushion block connector are arranged oppositely and eccentrically, the prosthesis connector is inserted into the center hole of the prosthesis connecting column, and the center cushion block connector is inserted into the center cushion block connecting hole. The system provided by the invention can effectively solve the problem of poor bone coverage caused by eccentricity of a medullary cavity and a prosthesis, improves the comfort of a patient, is good in overall supporting performance, can prevent collapse after bone defect repair, can ensure initial stability, and is beneficial to later-stage bone growth.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, in particular to an adjustable eccentric knee joint central defect filling system. Background Art

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

[0003] Total knee arthroplasty and removal will cause varying degrees of bone defects on the distal femoral surface and metaphysis, and the proximal tibial surface and metaphysis. Common methods include filling with bone cement, bone filling blocks, etc. to ensure a support environment between the prosthesis and the bone. Filling blocks have a better effect than bone cement, but there is a problem with the currently used bone filling block system. Due to the eccentricity between the medullary cavity and the prosthesis, or due to reasons such as bone filling block design and prosthesis operation, the prosthesis cannot have better bone coverage, causing discomfort to 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 eccentricity between the medullary cavity and the prosthesis and improve patient comfort.

[0005] The present invention is achieved through the following solutions: An adjustable eccentric knee joint central defect filling system includes an eccentric conversion joint, a central pad and a prosthesis, wherein the prosthesis is provided with a central hole of a prosthesis connecting column, the central pad is provided with a central pad connecting hole, the eccentric conversion joint is provided with a prosthesis connector and a central pad connector, the prosthesis connector is opposite to the central pad connector and is eccentrically arranged, the prosthesis connector is inserted into the central hole of the prosthesis connecting column, and the central pad connector is inserted into the central pad connecting hole.

[0006] Preferably, the central spacer has a frustum-shaped structure with a large bottom diameter and a small top diameter.

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

[0008] Preferably, the central pad connection hole is an arc-shaped structure with a concave middle portion.

[0009] Furthermore, the center pad and the side walls of the prosthesis are provided with top screw mounting holes, the end of the center pad connector is provided with a center pad top screw mounting portion, the end of the prosthesis connector is provided with a prosthesis top screw mounting portion, the center pad top screw mounting portion and the prosthesis top screw mounting portion are both provided with arc-shaped concave outer side walls, and the center pad and the prosthesis are fixed to the eccentric conversion joint at the corresponding top screw mounting holes by top screws.

[0010] Furthermore, the prosthetic connector and the center pad connector are both frustum-shaped structures, the center hole of the prosthetic connector column matches the prosthetic connector, the lower part of the center pad connector hole matches the center pad connector, and the upper part of the center pad connector hole matches the shape of the extension rod inserted into the medullary cavity of the bone.

[0011] Furthermore, the ends of the prosthesis connector and the center block connector are both provided with connector screw mounting holes, and the prosthesis is provided with prosthesis screw mounting holes.

[0012] Preferably, the outer side of the central spacer is a porous trabecular structure.

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

[0014] Preferably, the central spacer is made by additive manufacturing technology.

[0015] Beneficial effects of the invention: The adjustable eccentric knee joint center defect filling system provided by the present invention is provided with an eccentric conversion joint and a center pad. The prosthesis connector of the eccentric conversion joint is opposite to the center pad connector and is eccentrically arranged. The prosthesis connector is inserted into the center hole of the prosthesis connecting column, and the center pad connector is inserted into the center pad connecting hole. It can effectively solve the problem of poor bone coverage caused by eccentricity between the medullary cavity and the prosthesis, improve the patient's comfort, and has good overall support, which can prevent the collapse of the bone defect after repair; and because the center pad and the prosthesis are fixed to the eccentric conversion joint by top screws or screws, relative rotation between the components can be prevented, thereby obtaining better initial stability; in addition, the outer side of the center pad is a porous trabecular bone structure, which can not only improve the overall strength, but also achieve biological fixation without the need for bone cement fixation, effectively preventing bone cement from penetrating into the trabecular bone structure and affecting bone ingrowth. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the eccentric conversion joint of the present invention.

[0017] Figure 2 It is a structural schematic diagram of the center pad of the present invention.

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

[0019] Figure 4 It 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 figure: 1. Eccentric conversion joint; 11. Prosthesis connector; 12. Center pad connector; 13. Center pad top screw mounting portion; 14. Prosthesis top screw mounting portion; 15. Connector screw mounting hole; 16. Prosthesis screw mounting hole; 2. Center pad; 21. Center pad connecting hole; 22. Step; 23. Make way opening; 24. Top screw mounting hole; 3. Femoral prosthesis; 31. Center hole of prosthesis connecting column; 4. Tibial prosthesis. DETAILED DESCRIPTION

[0021] The adjustable eccentric knee joint central defect filling system includes an eccentric conversion joint 1, a central pad 2 and a prosthesis. The structural diagram of the eccentric conversion joint is shown in FIG. Figure 1 As shown, the schematic diagram of the central pad structure is as follows Figure 2 As shown, the schematic diagram of the assembly structure of the eccentric conversion joint, the center pad and the femoral prosthesis 3 is as shown in Figure 3 As shown, the schematic diagram of the assembly structure of the eccentric conversion joint, the center pad and the tibial prosthesis 4 is as shown in Figure 4 As shown, the prosthesis is provided with a prosthesis connecting column center hole 31, the center pad is provided with a center pad connecting hole 21, and the eccentric conversion joint is provided with a prosthesis connecting head 11 and a center pad connecting head 12. The prosthesis connecting head is opposite to the center pad connecting head and is eccentrically arranged. 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.

[0022] Specifically, the relative eccentric distance between the prosthesis connector and the central spacer connector can be set as needed, and the eccentric distance can also be zero, that is, not eccentric.

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

[0024] Preferably, the center pad has a cone-shaped structure with a large bottom diameter and a small top diameter, which can form a center pad with anatomical characteristics, making the structure more consistent with the human skeletal structure, and by using rounded transitions on the overall edges, it can reduce the pain of soft tissue after implantation into the human body. The cone-shaped structure conforms to the shape of the bone defect area at the stump end of the knee joint, can fill the defect area, and can also effectively prevent the center pad of the knee joint from sinking again, thereby increasing the overall stability.

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

[0026] Preferably, the center pad connection hole is an arc-shaped structure with a concave middle part, which facilitates the center pad connection head of the eccentric conversion joint to be inserted into the lower part of the center pad connection hole, and the other end of the extension rod inserted into the medullary cavity of the backbone is inserted into the upper part of the center pad connection hole, and respectively matches the shape of the extension rod inserted into the medullary cavity of the backbone and the center pad connection head of the eccentric conversion joint to form a good tight fit.

[0027] Furthermore, a top screw mounting hole 24 is provided on the center pad and the side wall of the prosthesis, a center pad top screw mounting portion 13 is provided on the end of the center pad connector, and a prosthesis top screw mounting portion 14 is provided on the end of the prosthesis connector. The center pad top screw mounting portion and the prosthesis top screw mounting portion are both provided with an arc-shaped concave outer side wall, and the center pad and the prosthesis are fixed to the eccentric conversion joint at the corresponding top screw mounting holes by top screws, so that the top screws can be installed at the top screw mounting holes, and the top screws are pressed against the arc-shaped concave outer side wall of the prosthesis top screw mounting portion or the center pad top screw mounting portion to prevent relative rotation between the eccentric conversion joint and the center pad or between the eccentric conversion joint and the prosthesis, thereby enabling the adjustable eccentric knee joint center defect filling system to obtain better initial stability.

[0028] Furthermore, the prosthesis connector and the center pad connector are both frustum-shaped structures, the center hole of the prosthesis connecting column matches the prosthesis connector, the lower part of the center pad connecting hole matches the center pad connector, and the upper part of the center pad connecting hole matches the shape of the extension rod, so that the eccentric conversion joint, the center pad and the prosthesis can form a better and tighter fit.

[0029] Furthermore, the ends of the prosthesis connector and the center block connector are both provided with connector screw mounting holes 15, and the prosthesis is provided with prosthesis screw mounting holes 16, which facilitate fixed connection with the femoral prosthesis or the tibial prosthesis through screws.

[0030] Preferably, the outer side of the central pad is a porous trabecular structure, which can not only improve the overall strength but also achieve biological fixation without the need for bone cement fixation, effectively preventing bone cement from penetrating into the trabecular structure and affecting bone ingrowth.

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

[0032] Preferably, the central pad is manufactured by additive manufacturing technology, which is convenient, fast and low-cost to manufacture.

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

[0034] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. Adjustable eccentric knee joint central defect filling system, characterized by: It includes an eccentric conversion joint, a center pad and a prosthesis, the prosthesis is provided with a center hole of a prosthesis connecting column, 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 is opposite to the center pad connecting head and is eccentrically arranged, the prosthesis connecting head is inserted into the center hole of the prosthesis connecting column, and the center pad connecting head is inserted into the center pad connecting hole.

2. The adjustable eccentric knee joint central defect filling system according to claim 1, characterized in that: The central pad is in the shape of a truncated cone with a large bottom diameter and a small top diameter.

3. The adjustable eccentric knee joint central defect filling system according to claim 2, characterized in that: The bottom of the central pad is provided with a clearance opening, and the top of the clearance opening is provided with a step, and the central pad connection hole is located above the step.

4. The adjustable eccentric knee joint central defect filling system according to claim 3, characterized in that: The central pad connection hole is an arc-shaped structure with a concave middle portion.

5. The adjustable eccentric knee joint central defect filling system according to claim 1, characterized in that: The center pad and the side wall of the prosthesis are both provided with a top screw mounting hole, the end of the center pad connecting head is provided with a center pad top screw mounting portion, the end of the prosthesis connecting head is provided with a prosthesis top screw mounting portion, the center pad top screw mounting portion and the prosthesis top screw mounting portion are both provided with an arc-shaped concave outer side wall, and the center pad and the prosthesis are fixed to the eccentric conversion joint at the corresponding top screw mounting holes by top screws.

6. The adjustable eccentric knee joint central defect filling system according to claim 1, characterized in that: The prosthesis connector and the center pad connector are both frustum-shaped structures, the center hole of the prosthesis connecting column matches the prosthesis connector, the lower part of the center pad connecting hole matches the center pad connecting head, and the upper part of the center pad connecting hole matches the shape of the extension rod inserted into the medullary cavity of the bone.

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

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

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

10. The adjustable eccentric knee joint central defect filling system according to claim 1, characterized in that: The central pad is made by additive manufacturing technology.

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