Knee prosthesis

Abstract

The application relates to the technical field of bone prosthesis, in particular to a knee joint prosthesis. The knee joint prosthesis comprises a femoral component, a tibial shim and a tibial component. The tibial shim is fixed on the tibial component. The femoral component comprises a front bending part, a middle bottom part and a rear bending part which are sequentially connected. The femoral component is provided with a continuous sliding hole which is arranged along the middle bottom part to the rear bending part. The femoral component further comprises a blocking column and an upper inserting rod. The blocking column is arranged at the front end of the sliding hole adjacent to the front bending part. The blocking column is inclined and protrudes downward. The upper inserting rod is arranged on the inner surface of the middle bottom part. The convex column of the tibial shim can be inserted into the sliding hole and moves along the sliding hole to the front end of the sliding hole and abuts against the blocking column. When the middle bottom part is opposite to the tibial shim, the convex column moves to the front end of the sliding hole, the knee joint is in an upright state, and the convex column abuts against the blocking column at this time, thereby preventing the rotation of the femoral component relative to the convex column, that is, preventing the forward bending movement of the knee joint, and being beneficial to the rapid recovery of the knee joint function of the patient after the operation.

Description

Technical Field

[0001] This application relates to the field of bone prosthesis technology, and more specifically, to a knee joint prosthesis. Background Technology

[0002] The knee joint, composed of the lower end of the femur, the upper end of the tibia, and the patella, is the largest and most complex joint in the human body, belonging to the trochlear joint category. Due to age, disease, or trauma, the knee joint may be injured, leading to pain, swelling, and limited mobility.

[0003] For severe cases of knee arthritis, osteoarthritis, degenerative joint disease, and other joint injuries that cause unrelieved pain, knee replacement surgery may be performed, which involves replacing the damaged joint with an artificial one.

[0004] A knee prosthesis is an artificial joint used in knee replacement surgery, typically made of a metal prosthesis and a plastic pad. However, most knee prostheses lack anti-flexion mechanisms. After installation, the anti-flexion limiting tissues of the knee joint are usually disrupted, making the knee prone to forward bending during postoperative recovery. This can lead to slow recovery and even complications. Summary of the Invention

[0005] In order to improve the lack of anti-bending mechanism in general knee joint prostheses, which usually destroys the anti-bending restriction tissue of the human knee joint after the installation of knee joint prostheses, the knee joint is prone to bending forward during the postoperative recovery process, resulting in slow postoperative recovery and even complications. This application proposes a knee joint prosthesis that can prevent forward bending and adopts the following technical solution.

[0006] A knee joint prosthesis includes a femoral component, a tibial pad, and a tibial component.

[0007] The femoral assembly includes an anterior curved portion, a mid-base portion, and a posterior curved portion connected in sequence. The anterior and posterior curved portions curve towards the same side from both ends of the mid-base portion. The femoral assembly has a continuous sliding hole extending from the mid-base portion to the posterior curved portion. The femoral assembly also includes a stop post and an upper insert. The stop post is disposed at the front end of the sliding hole adjacent to the anterior curved portion. The stop post protrudes downward at an angle. The upper insert is disposed on the inner surface of the mid-base portion.

[0008] The tibial pad includes a cushioning seat and a protruding post. The tibial assembly includes a support plate and a lower insertion rod. The lower insertion rod is fixed to the bottom surface of the support plate.

[0009] The buffer seat is fixed inside the support plate. The protrusion is integrally formed on the upper surface of the buffer seat. The protrusion can be fitted into the sliding hole and move along the sliding hole to the front end of the sliding hole to abut against the stop post.

[0010] By adopting the above technical solution, the forward bending portion corresponds to the patella position, and the protruding post can be adapted to be inserted into the sliding hole and move along the sliding hole, so that the middle bottom and the backward bending portion slide on the tibial pad. When the middle bottom is directly opposite the tibial pad, the protruding post moves to the front end of the sliding hole, the knee joint is in an upright position, and at this time the protruding post abuts against the stop post, preventing the femoral component from rotating relative to the protruding post, that is, preventing the forward bending movement of the knee joint. After knee replacement surgery, the patient is less likely to cause the knee joint to bend forward during the recovery process, which is conducive to the patient's rapid recovery of knee joint function after surgery.

[0011] As an improvement to this knee joint prosthesis, the angle between the retaining post and the upper insert is 10°~20°. The angle between the protruding post and the lower insert is 10°~20°.

[0012] By adopting the above technical solution, the relatively small angle of 10° to 20° prevents the retaining post and the convex post from sliding against each other after contact, thus preventing rotation of the femoral component and making the knee joint prosthesis less prone to forward flexion. This relatively small angle also prevents the retaining post from excessively tilting outwards and contacting the synovium, patella, etc., reducing damage to the synovium and not hindering patellar movement.

[0013] As an improvement to this knee joint prosthesis, the retaining post faces downward and is tilted forward. The protruding post faces upward and is tilted backward.

[0014] By adopting the above technical solution, the protruding post faces upward and tilts backward. When the knee joint is bent, the protruding post can also be embedded in the sliding hole, thereby guiding the femoral component to rotate back to the upright position. The stop post faces downward and tilts forward, minimizing the impact damage from collision with the protruding post and effectively protecting both the stop post and the protruding post.

[0015] As an improvement to the knee joint prosthesis, when the protrusion moves along the sliding hole and abuts against the stop post, the middle bottom fits snugly against the tibial pad.

[0016] By adopting the above technical solution, the upper insertion rod is used to be inserted parallel to the femur of the human body for fixation, and the lower insertion rod is used to be inserted parallel to the tibia of the human body for fixation. When the knee joint reaches the upright position, the middle bottom fits snugly against the tibia pad, the structure is stable, and at the same time the protruding post abuts against the stop post, restricting the knee joint in the upright position from continuing to bend forward, thus protecting the human body.

[0017] As an improvement to the knee joint prosthesis, the first front side of the protrusion is planar, the second rear side of the stop post is planar, and when the protrusion moves along the sliding hole and abuts against the stop post, the first front side of the protrusion and the second rear side of the stop post are in adaptive planar contact.

[0018] By adopting the above technical solution, the planar fit contact structure makes the forward rotation resistance of the femoral component relative to the tibial pad large, accurately controls the relative angle between the femoral component and the tibial pad, and precisely controls the knee joint to be in a standard upright position.

[0019] As an improvement to the knee joint prosthesis, the center of the forward bending portion is recessed inward to form a smooth groove that smoothly extends to the stop post.

[0020] By adopting the above technical solution, the recessed groove connects to the patella, and the recessed groove extends smoothly to the stop post so as not to hinder the movement of the patella, so that the patella can move smoothly.

[0021] As an improvement to the knee joint prosthesis, the posterior bending portion includes a left bending plate, a right bending plate, and a connecting rod. The connecting rod connects the left bending plate and the right bending plate. The left bending plate, the connecting rod, and the right bending plate form a portion of the sliding hole.

[0022] By adopting the above technical solution, the connecting rod can serve as the fulcrum of the protruding column. When the knee joint is bent, the protruding column can rest against the connecting rod, making it less likely for the femoral component and tibial pad to become displaced during the back-and-forth switching between bending and standing.

[0023] As an improvement to the knee joint prosthesis, the connecting rod is a rearwardly curved cylinder. The first rearward side of the protruding post is a rearwardly convex curved surface. When the protruding post moves along the sliding hole to the rear end of the sliding hole, the first rearward side of the protruding post can fit comfortably against the connecting rod.

[0024] By adopting the above technical solution, when the knee joint is bent, the convex curved surface of the convex column fits against the curved cylinder that bends backward, which helps the knee joint to rotate smoothly. At the same time, the upper and lower ends of the knee joint are less likely to become displaced.

[0025] As an improvement to this knee prosthesis, the upper surface of the tibial pad has a raised central ridge and two recessed side grooves. The mid-bottom and posterior flexion portion of the femoral assembly can slide adaptively in the two side grooves. The protruding post is integrally formed on the central ridge. The bottom surface of the tibial pad has two screw holes corresponding to the central ridge, and the tibial assembly has two connecting holes corresponding to the two screw holes. The knee prosthesis includes two screws, which pass through the connecting holes and the screw holes, thereby fixing the tibial assembly and the tibial pad together.

[0026] By adopting the above technical solution, the tibial component and the tibial pad are firmly connected, and the tibial pad and the femoral component are smoothly slidably connected.

[0027] As an improvement to the knee joint prosthesis, the upper surface of the tibial assembly is provided with an arc-shaped front retainer and a concave V-shaped rear retainer. The bottom surface of the tibial pad has an anterior and a posterior clearance groove. The tibial pad is mounted on the tibial assembly such that the front retainer fits into the anterior clearance groove, and the rear retainer fits into the posterior clearance groove.

[0028] By adopting the above technical solution, the tibial component further restricts the anterior and posterior sliding of the tibial pad, and the positioning of the tibial pad is more fixed.

[0029] In summary, with the knee joint prosthesis of this application, when the middle and bottom part is directly aligned with the tibial pad, the protruding post moves to the front end of the sliding hole, the knee joint is in an upright position, and at this time the protruding post abuts against the stop post, preventing the femoral component from rotating relative to the protruding post, thus preventing the knee joint from flexing forward. After knee replacement surgery, the patient is less likely to experience forward bending of the knee joint during the recovery process, which is conducive to the patient's rapid recovery of knee joint function after surgery. Attached Figure Description

[0030] Figure 1 This is a connection diagram of a knee joint prosthesis.

[0031] Figure 2 for Figure 1 An exploded view of a knee joint prosthesis.

[0032] Figure 3 for Figure 1 A top view of the femoral component in a knee joint prosthesis.

[0033] Figure 4 for Figure 2 Structural diagram of a knee joint prosthesis from an overhead view.

[0034] Figure 5 for Figure 4 A structural diagram of the left side of a knee joint prosthesis.

[0035] Figure 6 for Figure 3 Another perspective view of the femoral component.

[0036] Figure 7 for Figure 4 Another structural view of the knee joint prosthesis.

[0037] Reference numerals: Femoral component 1, Tibial pad 2, Tibial component 3, Anterior bending portion 11, Middle bottom 12, Posterior bending portion 13, Sliding hole 14, Stop post 15, Upper insertion rod 16, Buffer seat 21, Protruding post 22, Support plate 31, Lower insertion rod 32, Reinforcing rib 33, First anterior side 221, Second posterior side 151, Recessed groove 111, Left bending plate 131, Right bending plate 132, Connecting rod 133, First posterior side 222, Middle ridge 211, Side groove 212, Screw hole 213, Connecting hole 311, Screw 34, Front baffle 312, Rear baffle 313, Front clearance groove 214, Rear clearance groove 215. Detailed Implementation

[0038] The following describes some embodiments of knee joint prostheses in detail with reference to the accompanying drawings.

[0039] like Figure 1 A knee joint prosthesis includes a femoral component 1, a tibial pad 2, and a tibial component 3. The femoral component 1 and the tibial component 3 can be made of stainless steel, titanium alloy, etc., and the tibial pad 2 can be made of a composite material of polyethylene, acrylamide, and silica, etc.

[0040] The tibial pad 2 is fixed to the tibial assembly 3. The femoral assembly 1 is used to slide and engage with the tibial pad 2.

[0041] like Figure 2 The femoral component 1 includes an anterior bending portion 11, a middle base 12, and a posterior bending portion 13 connected in sequence. The anterior bending portion 11 and the posterior bending portion 13 bend from both ends of the middle base 12 toward the same side, making the femoral component 1 U-shaped. The anterior bending portion 11 is slightly higher than the posterior bending portion 13, and the anterior bending portion 11 itself also has a structure that is higher on one side and lower on the other, so as to fit and cover the end of the human femur.

[0042] like Figure 3 The femoral component 1 has a continuous sliding hole 14 extending from the middle bottom 12 to the posterior bend 13.

[0043] like Figure 4 The femoral component 1 further includes a retaining post 15 and two upper insert rods 16. The retaining post 15 is disposed at the front end of the sliding hole 14 adjacent to the anterior bending portion 11. The retaining post 15 protrudes downward at an angle. The two upper insert rods 16 are disposed on the inner surface of the middle bottom 12.

[0044] like Figure 2 The tibial pad 2 includes a buffer seat 21 and a protruding post 22.

[0045] like Figure 2The tibial assembly 3 includes a support plate 31 and a lower insertion rod 32. The lower insertion rod 32 is fixed to the bottom surface of the support plate 31. The tibial assembly 3 may also include two reinforcing ribs 33, which are fixed to both sides of the lower insertion rod 32 and to the bottom surface of the support plate 31.

[0046] The buffer seat 21 is fixed inside the support plate 31. The protruding post 22 is integrally formed on the upper surface of the buffer seat 21. The protruding post 22 can be adapted to be inserted into the sliding hole 14 and move along the sliding hole 14 to the front end of the sliding hole 14 and abut against the stop post 15.

[0047] In the above-mentioned knee joint prosthesis, the forward bending portion 11 corresponds to the patella. The protruding post 22 can be fitted into the sliding hole 14 and move along the sliding hole 14, so that the middle bottom 12 and the backward bending portion 13 slide on the tibial pad 2. When the middle bottom 12 is directly opposite the tibial pad 2, the protruding post 22 moves to the front end of the sliding hole 14, and the knee joint is in an upright position. At this time, the protruding post 22 abuts against the stop post 15, preventing the femoral component 1 from rotating relative to the protruding post 22, thus preventing the forward bending movement of the knee joint. After knee replacement surgery, the patient is less likely to experience forward bending of the knee joint during the recovery process, which is conducive to the patient's rapid recovery of knee joint function after surgery.

[0048] refer to Figure 4 The inclination angle of the stop post 15 and the protruding post 22 can be such that the included angle α between the stop post 15 and the upper insert rod 16 is 10°~20°, for example, 15°. (Reference) Figure 2 The included angle β between the protruding post 22 and the lower insert rod 32 is 10°~20°, for example, 15°. This relatively small angle of 10°~20° makes it less likely for the retaining post 15 and the protruding post 22 to slide against each other after they abut, thus preventing rotation of the femoral component 1 and making it less likely for the knee joint prosthesis to flex forward. This relatively small angle of 10°~20° also prevents the retaining post 15 from excessively tilting outward and abutting against the synovium, patella, etc., reducing damage to the synovium and not hindering the movement of the patella.

[0049] One optional tilting direction for the retaining post 15 and the protruding post 22 is that the retaining post 15 is tilted downwards and forwards, and the protruding post 22 is tilted upwards and backwards. With the protruding post 22 tilted upwards and backwards, it can also engage with the sliding hole 14 when the knee joint is bent, thereby guiding the femoral component 1 to rotate back to an upright position. The downward and forward tilt of the retaining post 15 minimizes the impact damage from collisions with the protruding post 22, effectively protecting both the retaining post 15 and the protruding post 22.

[0050] To enhance the stability of the knee prosthesis and effectively prevent forward flexion of the knee, the protruding post 22 is positioned so that when it moves along the sliding hole 14 and abuts against the stop post 15, the middle base 12 fits snugly against the tibial pad 2. In conventional installation, the upper insertion rod 16 is inserted parallel to the femur for fixation, and the lower insertion rod 32 is inserted parallel to the tibia for fixation. When the knee joint is in an upright position, the middle base 12 fits snugly against the tibial pad 2, providing structural stability. Simultaneously, the protruding post 22 abuts against the stop post 15, restricting further forward flexion of the knee joint in an upright position and protecting the patient.

[0051] like Figure 5 To more reliably prevent the relative rotation of the stop post 15 and the protruding post 22 after they abut against each other, the first front side surface 221 of the protruding post 22 can be set to a planar shape. For example... Figure 6 The second rear side 151 of the stop post 15 is planar, and when the protruding post 22 moves along the sliding hole 14 and abuts against the stop post 15, the first front side 221 of the protruding post 22 and the second rear side 151 of the stop post 15 are in adaptive planar contact. This planar contact structure results in greater forward rotational resistance for the femoral component 1 relative to the tibial pad 2, precisely controlling the relative angle between the femoral component 1 and the tibial pad 2, and accurately controlling the knee joint to be at a standard upright angle.

[0052] refer to Figure 5 An optional structure of the anterior bending portion 11 in the femoral component 1 is that the middle of the anterior bending portion 11 is recessed inward to form a smooth groove 111, and the groove 111 smoothly extends to the stop post 15. The groove 111 engages with the patella, and the groove 111 smoothly extends to the stop post 15 so as not to impede the movement of the patella, allowing the patella to move smoothly.

[0053] like Figure 6 An optional structure of the posterior bending portion 13 in the femoral component 1 includes a left bending plate 131, a right bending plate 132, and a connecting rod 133. The connecting rod 133 connects the left bending plate 131 and the right bending plate 132. The left bending plate 131, the connecting rod 133, and the right bending plate 132 form a portion of the sliding hole 14. The connecting rod 133 can serve as a fulcrum for the protruding post 22. When the knee joint is bent, the protruding post 22 can abut against the connecting rod 133, making it less likely for the femoral component 1 and the tibial pad 2 to become displaced during the switching between bending and upright positions.

[0054] refer to Figure 3 An improved structure of the posterior bending portion 13 in the femoral component 1 is that the connecting rod 133 is a posteriorly bent cylinder. For example... Figure 7The first rear side surface 222 of the protruding post 22 is a rearwardly protruding convex curved surface. When the protruding post 22 moves along the sliding hole 14 to the rear end of the sliding hole 14, the first rear side surface 222 of the protruding post 22 can fit comfortably against the connecting rod 133. When the knee joint is bent, the convex curved surface of the protruding post 22 fits against the rearwardly bent cylinder, which helps the knee joint to perform smooth rotational movements, and at the same time, the upper and lower ends of the knee joint are less likely to become displaced.

[0055] like Figure 7 An optional structure for the tibial pad 2 and tibial assembly 3 is that the upper surface of the tibial pad 2 has a raised central ridge 211 and two recessed side grooves 212. The mid-bottom 12 and the posterior bending portion 13 of the femoral assembly 1 can slide adaptively in the two side grooves 212. The protruding post 22 is integrally formed on the central ridge 211. Figure 7 and Figure 4 The tibial pad 2 has two screw holes 213 on its bottom surface corresponding to the midline 211, and the tibial assembly 3 has two connecting holes 311 corresponding to the two screw holes 213. The knee joint prosthesis includes two screws 34, which pass through the connecting holes 311 and the screw holes 213, so that the tibial assembly 3 and the tibial pad 2 are fixedly connected, while the tibial pad 2 and the femoral assembly 1 can slide smoothly against each other.

[0056] In addition to the connection of screw 34, the tibial pad 2 and the tibial component 3 can also be bonded together with bone cement.

[0057] like Figure 7 To enhance the installation stability of the tibial pad 2, an arc-shaped front baffle 312 and a concave V-shaped rear baffle 313 are provided on the upper surface of the tibial assembly 3. Figure 4 The bottom surface of the tibial pad 2 has a front relief groove 214 and a rear relief groove 215. The tibial pad 2 is mounted on the tibial assembly 3 such that the front baffle 312 is fitted into the front relief groove 214, and the rear baffle 313 is fitted into the rear relief groove 215. The front baffle 312 and the rear baffle 313 of the tibial assembly 3 further restrict the anterior and posterior sliding of the tibial pad 2, and the tibial pad 2 is further locked.

[0058] In the above-described knee prosthesis, the femoral component 1 can be inserted into the medullary cavity where the original femoral head surface has been removed via its own upper insertion rod 16. It becomes more robust through pressure. For medullary cavities with insufficient bone volume or osteoporosis, bone cement needs to be applied for bonding. Similarly, the tibial component 3 can be inserted into the medullary cavity where the original tibial head surface has been removed via its own lower insertion rod 32. It becomes more robust through pressure. For medullary cavities with insufficient bone volume or osteoporosis, bone cement needs to be applied for bonding.

[0059] This solution provides a knee joint prosthesis that can prevent forward flexion of the knee joint. When the mid-bottom 12 is directly opposite the tibial pad 2, the protrusion 22 moves to the front end of the sliding hole 14, the knee joint is in an upright position, and at this time the protrusion 22 abuts against the stop post 15, preventing the femoral component 1 from rotating relative to the protrusion 22, thus preventing forward flexion of the knee joint. After knee replacement surgery, the patient is less likely to experience forward bending of the knee joint during the recovery process, which is conducive to the patient's rapid recovery of knee joint function after surgery and reduces the risk of complications.

[0060] The above are merely some embodiments of this application. The scope of protection of this application is not limited to the above embodiments. For those skilled in the art, any improvements and modifications made without departing from the inventive design of this application should also fall within the scope of protection of this application.

Claims

1. A knee joint prosthesis, characterized in that, Includes femoral component (1), tibial pad (2) and tibial component (3); The femoral assembly (1) includes an anterior curved portion (11), a mid-base portion (12), and a posterior curved portion (13) connected in sequence; the anterior curved portion (11) and the posterior curved portion (13) bend from both ends of the mid-base portion (12) toward the same side; the femoral assembly (1) has a continuous sliding hole (14) extending from the mid-base portion (12) to the posterior curved portion (13); the femoral assembly (1) also includes a stop post (15) and an upper insertion rod (16); the stop post (15) is disposed in the sliding hole (14) near the front end of the anterior curved portion (11); the stop post (15) protrudes downward at an angle; the upper insertion rod (16) is disposed on the inner surface of the mid-base portion (12); The tibial pad (2) includes a buffer seat (21) and a protruding post (22); the tibial assembly (3) includes a support plate (31) and a lower insertion rod (32); the lower insertion rod (32) is fixed to the bottom surface of the support plate (31); The buffer seat (21) is fixed inside the support plate (31); the protrusion (22) is integrally formed on the upper surface of the buffer seat (21); the protrusion (22) can be adapted to be inserted into the sliding hole (14) and move along the sliding hole (14) to the front end of the sliding hole (14) and abut against the stop post (15).

2. The knee joint prosthesis according to claim 1, characterized in that, The included angle between the stop post (15) and the upper insert rod (16) is 10°~20°; the included angle between the protruding post (22) and the lower insert rod (32) is 10°~20°.

3. The knee joint prosthesis according to claim 1, characterized in that, The stop post (15) faces downward and is tilted forward; the protruding post (22) faces upward and is tilted backward.

4. The knee joint prosthesis according to any one of claims 1 to 3, characterized in that, When the protruding post (22) moves along the sliding hole (14) and abuts against the stop post (15), the middle bottom (12) fits into the tibial pad (2).

5. The knee joint prosthesis according to claim 4, characterized in that, The first front side (221) of the protruding post (22) is planar, the second rear side (151) of the stop post (15) is planar, and when the protruding post (22) moves along the sliding hole (14) and abuts against the stop post (15), the first front side (221) of the protruding post (22) and the second rear side (151) of the stop post (15) are in a matching planar contact.

6. The knee joint prosthesis according to claim 1, characterized in that, The middle of the forward curved portion (11) is recessed inward to form a smooth groove (111), which smoothly extends to the stop post (15).

7. The knee joint prosthesis according to claim 1, characterized in that, The rear curved portion (13) includes a left curved plate (131), a right curved plate (132), and a connecting rod (133); the connecting rod (133) connects the left curved plate (131) and the right curved plate (132); the left curved plate (131), the connecting rod (133), and the right curved plate (132) form a portion of the sliding hole (14).

8. The knee joint prosthesis according to claim 7, characterized in that, The connecting rod (133) is a curved cylinder that bends backward; the first rear side (222) of the protruding post (22) is a convex curved surface that protrudes backward; when the protruding post (22) moves along the sliding hole (14) to the rear end of the sliding hole (14), the first rear side (222) of the protruding post (22) can fit into the connecting rod (133).

9. The knee joint prosthesis according to claim 1, characterized in that, The upper surface of the tibial pad (2) has a raised central ridge (211) and two recessed side grooves (212); the middle bottom (12) and the posterior bending portion (13) of the femoral assembly (1) can slide in the two side grooves (212); the protruding post (22) is integrally formed on the central ridge (211); the bottom surface of the tibial pad (2) is provided with two screw holes (213) corresponding to the central ridge (211), and the tibial assembly (3) is provided with two connecting holes (311) corresponding to the two screw holes (213); the knee joint prosthesis includes two screws (34), and the two screws (34) pass through the connecting holes (311) and the screw holes (213) so that the tibial assembly (3) and the tibial pad (2) are fixedly connected.

10. The knee joint prosthesis according to claim 1, characterized in that, The upper surface of the tibial assembly (3) is provided with an arc-shaped front baffle (312) and a concave V-shaped rear baffle (313); the bottom surface of the tibial pad (2) is provided with a front relief groove (214) and a rear relief groove (215); the tibial pad (2) is installed on the tibial assembly (3) such that the front baffle (312) fits into the front relief groove (214) and the rear baffle (313) fits into the rear relief groove (215).

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