Third-generation new axis type knee joint prosthesis

Abstract

The invention discloses a third-generation new axis type knee joint prosthesis, and belongs to the technical field of medical prostheses. Comprising a femoral bone marrow needle, an osteotomy section, a femoral condyle, a tibia plateau pad, a tee joint, a tibia plateau support and a tibia bone marrow needle. The femoral bone marrow needle is connected to the far end of the osteotomy section, and the tibia bone marrow needle is connected to the far end of the tibia platform support; the femoral condyle is connected to the near end of the osteotomy section, and the tibial plateau pad is connected to the near end of the tibial plateau support; the end face of the femoral condyle is matched with the end face of the tibial plateau support. A bent three-way pad is arranged at the slotting position of the end part of the femoral condyle, and a step baffle is arranged behind the other end of the three-way pad; the step baffle can abut against the bent three-way pad. Abnormal sound and metal scraps caused by direct collision between metals can be prevented, the infection risk of a patient is reduced, and the postoperative satisfaction degree of the patient is improved.

Description

Technical Field

[0001] The invention relates to the technical field of medical prostheses, in particular to a third-generation new axial knee joint prosthesis. Background Art

[0002] There are many diseases that can be treated by knee replacement. Artificial knee replacement can be used to treat knee joint destruction caused by trauma, osteoarthritis, ankylosing spondylitis, rheumatoid arthritis and other diseases, knee valgus or flexion contracture deformity, etc. Artificial knee replacement can be used to treat. People with active knee infection, tuberculosis, and severe muscle and nerve dysfunction are not suitable for artificial knee replacement.

[0003] The existing hyperextension structure (tee and femoral condyle) is designed for metal-on-metal collision, which will produce abnormal noise, and metal debris from wear and impact, increasing the risk of infection for patients; the mid-axis design can only be implanted through a lateral approach and cannot meet the special needs of a clinical medial approach. Summary of the invention

[0004] The present invention provides a third-generation new axial knee joint prosthesis to solve the technical problem, which can prevent abnormal noise and metal debris caused by direct collision between metals, reduce the risk of infection for patients and improve their postoperative satisfaction.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The third generation new axial knee joint prosthesis comprises a femoral marrow needle 1, an osteotomy segment 2, a femoral condyle 3, a tibial plateau pad 5, a tee 6, a tibial plateau support 8 and a tibial marrow needle 9; the femoral marrow needle 1 is connected to the distal end of the osteotomy segment 2, and the tibial marrow needle 9 is connected to the distal end of the tibial plateau support 8; the femoral condyle 3 is connected to the proximal end of the osteotomy segment 2, and the tibial plateau pad 5 is connected to the proximal end of the tibial plateau support 8; the end surface of the femoral condyle and the end surface of the tibial plateau support are matched;

[0007] A slot is provided in the middle of the end of the femoral condyle; one end of the tee passes through the tibial plateau pad 5 and extends into the tibial plateau support 8, and the other end is located in the slot; the central shaft 10 passes through the end of the femoral condyle and the tee to achieve hinge connection;

[0008] A bending tee pad is arranged at the slot at the end of the femoral condyle, and a step stop is arranged at the rear of the other end of the tee; the step stop can be pressed against the bending tee pad.

[0009] Furthermore, a circular hole with a T-shaped cross-section is provided behind the femoral condyle groove; the bending tee pad is made of polyethylene material, and is provided with a T-shaped protrusion integrally formed therewith; the T-shaped protrusion is located in the circular hole, and the two are cooperatively connected.

[0010] Furthermore, the end of the femoral condyle is grooved to form a left block and a right block, and the central axis passes through the left block and the right block; the central axis is also provided with a central axis pad; the central axis pad is an annular structure, including an integrally formed longitudinal block and a transverse block; the longitudinal block is connected to one side of the transverse block and the central axes of the two coincide; the transverse block is located between the central axis and the tee, and the longitudinal block is located between the tee and the left block or the right block.

[0011] Furthermore, the inner diameters of the longitudinal block and the transverse block are the same, and the outer diameter of the longitudinal block is greater than the outer diameter of the transverse block.

[0012] Furthermore, the top of the tibial plateau support 8 is provided with a blind hole for the insertion of a tee; and the inner wall of the blind hole is provided with a bushing.

[0013] Furthermore, a centralizer is provided at the end of the femoral intramedullary needle 1.

[0014] Furthermore, it also includes a central axis anti-slip pad; a circle of inner grooves are provided in the through holes of the left and right stops; the central axes of the inner grooves and the through holes coincide with each other; and an inverted ring is provided on the central axis anti-slip pad, which is stuck in the inner groove.

[0015] Furthermore, there is a distance between the central axis of the tibial bone marrow needle and the central axis of the tee, and the size of the distance is any value between 3.5 mm and 4 mm.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The eccentric distance between the tibial bone marrow needle and the three-way joint is translated forward by 3.5-4mm, which can effectively prolong the use time of the prosthesis and better restore the patient's knee joint force line and later rehabilitation.

[0018] 2. Improved design of the central axis and femoral condyle, both medial and lateral approaches can be used for implantation, greatly meeting clinical surgical needs;

[0019] 3. A three-way pad (polyethylene material) is designed between the three-way and the femoral condyle to prevent direct collision between metal and metal to produce abnormal noise and metal debris, reduce the risk of infection for patients and improve their postoperative satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a side half-section structure of an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of a front half-section structure of an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the matching structure of the tee pad and the tee according to an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the matching structure of the shaft and the middle shaft pad in the embodiment of the present invention;

[0024] Figure 5 It is a schematic diagram of the translation direction of the tee according to an embodiment of the present invention.

[0025] Figure 6 Schematic diagram of the structure of the shaft anti-slip pad in an embodiment of the present invention.

[0026] Figure 7 It is a schematic diagram of the structure of the position of the three-way pad on the femoral condyle according to an embodiment of the present invention.

[0027] Figure 8 The stress cloud diagrams are compared before and after the improvement of the embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with embodiments, the purpose of which is only to better understand the content of the present invention. Therefore, the specific embodiments cited do not limit the protection scope of the present invention. In addition, the accompanying drawings only show parts related to the present invention rather than all structures.

[0029] The third generation new axial knee joint prosthesis comprises a femoral marrow needle 1, an osteotomy segment 2, a femoral condyle 3, a tibial plateau pad 5, a tee 6, a tibial plateau support 8 and a tibial marrow needle 9; the femoral marrow needle 1 is connected to the distal end of the osteotomy segment 2, and the tibial marrow needle 9 is connected to the distal end of the tibial plateau support 8; the femoral condyle 3 is connected to the proximal end of the osteotomy segment 2, and the tibial plateau pad 5 is connected to the proximal end of the tibial plateau support 8; the end surface of the femoral condyle and the end surface of the tibial plateau support are matched;

[0030] A slot is provided in the middle of the end of the femoral condyle; one end of the tee passes through the tibial plateau pad 5 and extends into the tibial plateau support 8, and the other end is located in the slot; the central shaft 10 passes through the end of the femoral condyle and the tee to achieve hinge connection;

[0031] A bending tee pad is arranged at the slot at the end of the femoral condyle, and a step stop is arranged at the rear of the other end of the tee; the step stop can be pressed against the bending tee pad.

[0032] Furthermore, a circular hole with a T-shaped cross-section is provided behind the femoral condyle groove; the bending tee pad is made of polyethylene material, and is provided with a T-shaped protrusion integrally formed therewith; the T-shaped protrusion is located in the circular hole, and the two are cooperatively connected.

[0033] Furthermore, the end of the femoral condyle is grooved to form a left block and a right block, and the central axis passes through the left block and the right block; the central axis is also provided with a central axis pad; the central axis pad is an annular structure, including an integrally formed longitudinal block and a transverse block; the longitudinal block is connected to one side of the transverse block and the central axes of the two coincide; the transverse block is located between the central axis and the tee, and the longitudinal block is located between the tee and the left block or the right block.

[0034] Furthermore, the inner diameters of the longitudinal block and the transverse block are the same, and the outer diameter of the longitudinal block is greater than the outer diameter of the transverse block.

[0035] Furthermore, the top of the tibial plateau support 8 is provided with a blind hole for the insertion of a tee; and the inner wall of the blind hole is provided with a bushing.

[0036] Furthermore, a centralizer is provided at the end of the femoral intramedullary needle 1.

[0037] Furthermore, it also includes a central axis anti-slip pad; a circle of inner grooves are provided in the through holes of the left and right stops; the central axes of the inner grooves and the through holes coincide with each other; and an inverted ring is provided on the central axis anti-slip pad, which is stuck in the inner groove.

[0038] Furthermore, there is a distance between the central axis of the tibial bone marrow needle and the central axis of the tee, and the size of the distance is any value between 3.5 mm and 4 mm.

[0039] Reference Figure 1 and Figure 2 The structure of the axial knee joint prosthesis of this embodiment is as follows:

[0040] The prosthetic structure 1 is a femoral medullary needle, and the appropriate medullary needle size can be selected according to the patient's condition;

[0041] Structure 2 is the osteotomy segment, and the osteotomy length is adjusted by different specifications;

[0042] Structure 3 is the femoral condyle, which restores knee flexion and extension, and is a bionic femoral condyle structure. The mid-axis hole structure is improved so that both the inner and outer sides can be placed in the mid-axis structure, which is convenient for intraoperative operation;

[0043] Structure 4 is a three-way pad (polyethylene material) to prevent the metal between the three-way and the femoral condyle from directly hitting each other to produce abnormal noise and debris, thereby reducing the risk of infection for patients;

[0044] Structure 5 is a tibial plateau pad, which is highly polished to reduce the wear of the upper part of the tibial plateau pad and the articular surface of the femoral condyle, thereby extending the service life of the prosthesis. It also has strong wear resistance and will not produce debris that may cause infection in patients.

[0045] Structure 6 is a three-way structure that can satisfy knee joint rotation and bounce stretching;

[0046] Structure 7 is a bushing to prevent direct metal collision between the tee and the tibial plateau support;

[0047] Structure 8 is a tibial plateau support, which is provided with a three-way hole for the three-way to slide in and fix the tibial plateau pad to prevent the platform pad from falling off. The lower part is fixed with the tibial medullary needle taper, and the three-way hole and the medullary needle are more in line with the human anatomical structure;

[0048] Structure 9 is a tibial bone marrow needle, which is fixed with the tibial plateau taper and can be selected in different sizes according to the patient's condition;

[0049] The structure 10 is a central axis, which is used to fix the femoral condyle and the tee, so that the tee has a rotation function;

[0050] Structure 11 is a central axis pad to prevent metal wear between the tee, central axis and femoral condyle;

[0051] Structure 12 is a central inserter, which has both the effect of preventing the medullary needle from rotating and facilitating the implantation of the medullary needle;

[0052] The structure 13 is a middle shaft anti-drop pad, which is inserted into the outer side of the middle shaft after the middle shaft is installed to prevent the middle shaft from falling out.

[0053] Reference Figure 3 and Figure 7 The slot at the end of the femoral condyle is provided with a bent tee pad (i.e. the tee pad mentioned above), and a step stop 14 is provided at the rear of the other end of the tee; the step stop can be against the bent tee pad. A round hole with a T-shaped cross section is provided at the rear of the femoral condyle slot; the bent tee pad is made of polyethylene, and is provided with a T-shaped protrusion 15 integrally formed therewith; the T-shaped protrusion is located in the round hole, and the two are matched and connected.

[0054] Reference Figure 4 The central axis is also provided with a central axis pad; the central axis pad is an annular structure, including an integrally formed longitudinal block and a transverse block; the longitudinal block is connected to one side of the transverse block, and the central axes of the two coincide; the transverse block is located between the central axis and the tee, and the longitudinal block is located between the tee and the left block or the right block. The inner diameters of the longitudinal block 16 and the transverse block 17 are the same, and the outer diameter of the longitudinal block is larger than the outer diameter of the transverse block.

[0055] Reference Figure 5 There is a distance between the central axis of the tibial bone marrow needle and the central axis of the tee, and the size of the distance is any value between 3.5mm and 4mm.

[0056] A tumor-type knee prosthesis was designed for a specific patient's knee tumor. In order to better restore the patient's knee joint force line and postoperative rehabilitation effect, it was found that the tibial bone marrow needle and the tee eccentricity were shifted forward by 3.5-4mm, which is more in line with the human anatomical structure. In order to facilitate clinical operation, the central axis is designed to be implanted both inside and outside to prevent direct collision between metal and metal to produce abnormal noise and metal debris, thereby reducing the risk of infection for patients.

[0057] According to the analysis standard, a load (1500N) is applied to the upper surface of the tibial plateau tray in a direction perpendicular to the platform surface, which is equivalent to the pressure on the tibial plateau tray when simulating a body weight of 70kg when walking. Separate finite element models are established for calculations before improvement (left picture, no translation of 3.5mm) and after improvement (right picture, translation of 3.5mm). In accordance with the provisions of ASTMF2996-19, finite element analysis and calculations were performed on the two types of tibial plateau trays, and the results are shown in Table 1. The purpose of this simulation is to compare the stress on the tibia of the tibial plateau tray before improvement and the tibial plateau tray after improvement. This stress is reflected in the finite element model of the tibia, and the stress results are recorded. The Mises cloud diagram is obtained as follows: Figure 8 As shown. The finite element model of the tibial plateau tray before and after improvement was established. Through finite element calculation, it was found that the stress of the improved tibial plateau tray was smaller, so the structure of the improved tibial plateau tray was more reasonable. This shows that the improved prosthesis structure is more in line with human biomechanics, can effectively prolong the use time of the prosthesis, better restore the patient's knee joint force line and late rehabilitation, and reduce the risk of late prosthesis revision and bone deformity due to long-term force line misalignment.

[0058] Reference Figure 6 The through holes of the left and right blocks are both provided with a circle of inner grooves; the central axis of the inner grooves and the through holes coincide; the central axis anti-offset pad is provided with an inverted ring, and the inverted ring 18 is stuck in the inner groove. The anti-rotation protrusion 19 is embedded in the notch of the left or right block for anti-rotation.

[0059] The present invention is not limited to the above embodiments, but may include more other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A third generation new axial knee joint prosthesis, comprising a femoral medullary needle (1), an osteotomy segment (2), a femoral condyle (3), a tibial plateau pad (5), a tee (6), a tibial plateau support (8) and a tibial medullary needle (9); the femoral medullary needle (1) is connected to the distal end of the osteotomy segment (2), and the tibial medullary needle (9) is connected to the distal end of the tibial plateau support (8); characterized in that: The femoral condyle (3) is connected to the proximal end of the osteotomy segment (2), and the tibial plateau pad (5) is connected to the proximal end of the tibial plateau support (8); the end surface of the femoral condyle and the end surface of the tibial plateau support are matched; A slot is provided in the middle of the end of the femoral condyle; one end of the tee passes through the tibial plateau pad (5) and extends into the tibial plateau support (8), and the other end is located in the slot; the middle shaft (10) passes through the end of the femoral condyle and the tee to achieve hinge connection; A bending tee pad is arranged at the slot at the end of the femoral condyle, and a step stop is arranged at the rear of the other end of the tee; the step stop can be pressed against the bending tee pad.

2. The third generation new axial knee prosthesis according to claim 1 is characterized in that: A circular hole with a T-shaped cross section is arranged behind the femoral condyle slot; the bending tee pad is made of polyethylene material, and is provided with a T-shaped protrusion formed integrally therewith; the T-shaped protrusion is located in the circular hole, and the two are matched and connected.

3. The third generation new axial knee prosthesis according to claim 1 is characterized in that: The end of the femoral condyle is grooved to form a left block and a right block, and the central axis runs through the left block and the right block; the central axis is also provided with a central axis pad; the central axis pad is an annular structure, including an integrally formed longitudinal block and a transverse block; the longitudinal block is connected to one side of the transverse block, and the central axes of the two coincide; the transverse block is located between the central axis and the tee, and the longitudinal block is located between the tee and the left block or the right block.

4. The third generation new axial knee prosthesis according to claim 3 is characterized in that: The inner diameters of the longitudinal block and the transverse block are the same, and the outer diameter of the longitudinal block is greater than the outer diameter of the transverse block.

5. The third generation new axial knee prosthesis according to claim 1 is characterized in that: The top of the tibial platform support (8) is provided with a blind hole for inserting a tee; the inner wall of the blind hole is provided with a bushing.

6. The third generation new axial knee prosthesis according to claim 1 is characterized in that: A centralizer is provided at the end of the femoral intramedullary needle (1).

7. The third generation new axial knee prosthesis according to claim 1 is characterized in that: It also includes a central axis anti-slip pad; a circle of inner grooves are arranged in the through holes of the left and right stops; the central axes of the inner grooves and the through holes coincide with each other; an inverted ring is arranged on the central axis anti-slip pad, and the inverted ring is stuck in the inner groove.

8. The third generation new axial knee prosthesis according to claim 1 is characterized in that: There is a distance between the central axis of the tibial bone marrow needle and the central axis of the tee, and the size of the distance is any value between 3.5mm and 4mm.

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