CN201175391Y - knee prosthesis - Google Patents

Abstract

The utility model provides an internal prosthesis for the knee joint, which comprises: a femoral prosthesis 1 connected with the distal end of the femur, a tibial liner 4 fixed on the tibial bearing 5, and a tibial ramus connected with the proximal end of the tibia Seat 5 is packed into tibial intercondylar crest 3 in tibial pad 4 intercondylar hole 4c and tibial bearing 5 boss 5f hole to ensure the relative position of tibial intercondylar crest 3 and tibial pad 4 and tibial bearing 5 screw 2. The inner condyle 4a of the tibial pad 4 and the articular surface of the outer condyle 4b correspond to the articular surface of the inner condyle 1a and the outer condyle 1b of the femoral prosthesis 1 respectively, to ensure that the femoral prosthesis 1 can be stretched on the tibial pad 4. After bending and rolling. The tibial intercondylar ridge 3 extends into the intercondylar area 1d of the femoral prosthesis to ensure the stability of the knee joint. Prosthesis 1 has a greater angle of external rotation in knee flexion, thereby achieving deep knee flexion.

Description

knee prosthesis

technical field

The utility model relates to a medical artificial joint, in particular to a knee prosthesis applied to the human body, which is used to replace the human body's natural knee which has lost all or part of its function due to pathological changes or injuries during the formation of the knee joint. joint.

Background technique

The development of artificial knee joints has a history of more than 40 years. When the natural knee joint of the human body loses all or part of its function due to disease or injury, it needs to be replaced with an artificial knee joint to reconstruct the knee joint and reduce the patient's pain. illness.

The so-called internal prosthesis of the knee joint includes two parts: the femoral prosthesis and the tibial prosthesis. Among them, the femoral prosthesis is connected to the distal end of the femur through a femoral mounting stem or screws, and has inner and outer condyles. The tibial prosthesis is divided into two parts, the tibial bearing and the tibial bearing. The tibial bearing is fixed at the proximal end of the tibia. The tibial lining is located between the femoral prosthesis and the tibial bearing and is fixed on the tibial bearing. The surfaces are respectively matched with the articular surfaces of the inner and outer condyles of the femoral prosthesis to simulate the normal natural knee joint movement process of the human body.

For the human natural knee joint, when the knee joint is in the knee extension position, the tibial intercondylar ridge extends into the femoral intercondylar groove, and together with the surrounding ligaments and soft tissues, it realizes the stability of the knee joint. As the knee begins to gradually flex, the external rotation angle of the femur relative to the tibia gradually increases. Therefore, in the internal prosthesis of the knee joint, the tibial intercondylar crest is designed to achieve the stability of the knee joint in extensor position. The bending angle of the joint. In U.S. Patent US6793680, a new type of tibial intercondylar ridge is proposed, the tibial intercondylar ridge protrudes on the front side of the knee joint to achieve the stability of the knee joint in extension, and is concave on the back side. To increase the external rotation of the femoral component relative to the tibial component during knee flexion. In U.S. Patent No. 7,066,963 and U.S. Pat. No. 6,902,582, the anterior part of the tibial intercondylar ridge is higher than the posterior part, on the one hand, the stability of the knee joint can be achieved, and on the other hand, the external rotation angle of the femoral prosthesis relative to the tibial prosthesis can be increased when the knee is flexed . However, the tibial intercondylar ridge and the tibial liner in these patents are integrated. When the wear of the tibial intercondylar ridge increases, the life of the entire tibial liner will be reduced, thereby affecting the stability of the knee prosthesis. .

Contents of the invention

Aiming at the deficiencies of the above technologies and patents, the utility model proposes a new human knee prosthesis for internal use. The purpose is: firstly, when the knee joint is in the knee extension position, the tibial intercondylar ridge extends into the femoral intercondylar groove Inside, it works with the surrounding ligaments and soft tissues to stabilize the knee joint. Secondly, the tibial intercondylar ridge can increase the external rotation angle of the femoral component relative to the tibial component, so as to increase the bending angle of the knee joint and achieve deep knee flexion. Finally, the tibial intercondylar crest and the tibial pad are designed separately, and the tibial intercondylar crest is made of wear-resistant metal materials to improve the wear resistance of the tibial prosthetic intercondylar crest, thereby ensuring the stability of the knee prosthesis .

The knee prosthesis described in the utility model is suitable for patients with intact ligaments and soft tissues around the knee joint.

The specific composition of the device:

Femoral prosthesis 1, this prosthesis is connected with femur distal end, has inner bone condyle 1a, outer bone condyle 1b and intercondylar region 1d;

Tibial bearing 5, which is connected with the proximal end of the tibia;

The tibial pad 4, which is fixed on the tibial abutment 5, has a medial condyle 4a and an external condyle 4b;

The tibial intercondylar ridge 3 is put into the tibial pad 4 intercondylar hole 4c and the tibial bearing 5 boss 5f hole, and the top perimeter is composed of surfaces 3a, 3b, 3c, 3d, 3e, wherein 3e is an inclined plane;

The screw 2 is connected with the intercondylar hole 4c of the tibial pad 4 and the boss 5f of the tibial bearing 5 .

The technical scheme implemented by the device:

When the knee joint is gradually extended from the knee flexion position to the knee extension position, the tibial intercondylar ridge 3 gradually extends into the intercondylar area 1a of the femoral prosthesis, and its top peripheral interfaces 3a, 3b, 3c, 3d are in contact with the intercondylar area 1d of the femoral prosthesis. Cooperate with each other to ensure the stability of knee extension.

When the bending angle of the knee joint increases gradually, the external rotation angle of the femoral prosthesis 1 gradually increases, and the part of the tibial intercondylar ridge 3 close to the outer condyle 1b of the femoral prosthesis 1 is resected, that is, the top circumference of the tibial intercondylar ridge 3 The interface 3e is an inclined plane, and the counterclockwise angle between 3e and the vertical line T is B. At this time, the posterior part 1c of the outer condyle 1b of the femoral prosthesis 1 will not interfere with the tibial intercondylar crest 3, thereby ensuring that the femoral prosthesis 1 There is a greater external rotation angle in the knee flexion position to increase the bending angle of the knee joint and finally achieve deep knee flexion.

The utility model has the advantages that: firstly, the knee extension stability of the knee joint can be realized. Second, the increased external rotation of the femoral component relative to the tibial component increases the knee flexion angle and enables deep knee flexion. Finally, the tibial intercondylar ridge is made of wear-resistant metal material, which not only improves the overall lifespan of the knee endoprosthesis, but also ensures the stability of the knee endoprosthesis in motion.

Description of drawings

Fig.1 Exploded perspective view of internal prosthesis of knee joint

Figure 2 Front view of the tibial prosthesis

Fig. 3 is a cross-sectional view about section line K-K in Fig. 2

Figure 4 is a cross-sectional view of the section line H-H in Figure 2

Figure 5 Symmetry example diagram about tibial intercondylar ridge

Serial number in the picture, 1. Femoral prosthesis, 2. Screw, 3. Tibial intercondylar ridge, 4. Tibial liner, 5. Tibial bearing A. Anterior side of knee joint, P. Posterior side of knee joint, M. Knee joint Medial, L. Lateral of the knee joint

Detailed ways

In Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the femoral prosthesis 1 is made of cobalt-chromium-molybdenum alloy material, connected with the distal end of the femur through femoral mounting stems or screws, and has inner condyle 1a and outer condyle 1b . The tibial bearing 5 is made of cobalt-chromium-molybdenum alloy material, and is connected with the proximal end of the tibia through the tibial mounting stem 5c and the fixing columns 5b, 5d, wherein the tibial mounting stem 5c is pressed into the tibial medullary cavity to play a major role of fixation, fixing Columns 5b and 5d are pressed into the cut surface of the proximal tibia to prevent rotation and assist fixation. The tibial liner 4 is made of ultra-high molecular weight polyethylene material, is located between the femoral prosthesis 1 and the tibial bearing 5, has the inner bone condyle 4a and the outer bone condyle 4b, and passes along the tibial bearing A-P direction (anterior-posterior direction) The protrusions 5a and 5e realize the positioning of the tibial pad 4 along the M-L direction (inner-outer direction), and the bayonet surfaces 4c, 4d along the A-P direction (anterior-posterior direction) on the tibial pad 4 and the tibial bearing 5 along the The cooperation of the bayonet surfaces 5h and 5j in the A-P direction (anterior-posterior direction) realizes the positioning and alignment of the tibial pad 4 along the A-P direction (anterior-posterior direction), and at the same time prevents the tibial pad 4 from dislocating upward. The tibial intercondylar ridge 3 is made of wear-resistant metal material, and is put into the tibial pad 4 intercondylar hole 4c and the tibial bearing 5 boss 5f hole. Part 2b of the screw 2 extends into the corresponding hole of the tibial intercondylar ridge 3 to realize the relative position positioning of the intercondylar ridge 3 and the tibial liner 4 and the tibial bearing 5. The corresponding threaded holes are connected to realize the relative position fixation of the intercondylar ridge 3 and the tibial liner 4 and the tibial bearing 5 .

In Fig. 1, when the knee joint gradually moves from the knee flexion position to the knee extension position, or from the knee extension position to the knee flexion position gradually, the articular surface of the medial condyle 1a and the articular surface of the lateral condyle 1b of the femoral prosthesis 1 are in contact with the tibial liner 4 respectively. The articular surface of the inner condyle 4a and the articular surface of the outer condyle 4b are matched to realize the bending, sliding and rolling back of the femoral prosthesis 1 on the tibial liner 4, thereby simulating the normal human natural knee joint movement process

In Figures 1 and 2, when the knee joint gradually moves from the knee flexion position to the knee extension position, the tibial intercondylar ridge 3 gradually extends into the intercondylar region 1d of the femoral prosthesis, and its top peripheral surfaces 3a, 3b, 3c, 3d It cooperates with the intercondylar area 1d of the femoral prosthesis to ensure the stability of the knee joint in extension.

In Fig. 1 and Fig. 2, when the knee joint gradually bends from the knee extension position, and gradually increases with the bending angle, the femoral prosthesis 1 is externally rotated relative to the tibial liner 4 along the R direction shown in Fig. The rotation angle gradually increases, and the part of the tibial intercondylar ridge 3 close to the outer condyle 1b of the femoral prosthesis 1 is resected, that is, the top peripheral interface 3e of the tibial intercondylar ridge 3 is an inclined plane, and the counterclockwise clamping between 3e and the vertical line T The angle is B, at this time, the posterior part 1c of the outer condyle 1b of the femoral prosthesis 1 will not interfere with the tibial intercondylar crest 3, so as to ensure that the femoral prosthesis 1 has a greater external rotation angle when the knee is flexed, so as to increase the The angle of flexion of the joint, and ultimately the deep flexion of the knee joint. The size of the included angle B can be selected, so that the most suitable tibial intercondylar crest 3 can be placed according to the actual condition of the patient.

The tibial intercondylar crest 3 or 3' is made of wear-resistant metal material, so when the knee joint gradually moves from the knee flexion position to the knee extension position, or gradually from the knee extension position to the knee flexion position, the tibial intercondylar crest 3 or 3' is relatively The wear amount of the femoral prosthesis 1 is greatly reduced, which can not only improve the overall lifespan of the knee joint internal prosthesis, but also ensure the motion stability of the knee joint internal prosthesis.

The knee prosthesis shown in Figure 1, Figure 2, Figure 3 and Figure 4 is suitable for the right knee joint.

In Fig. 2, the tibial intercondylar crest 3 is replaced by the tibial intercondylar crest symmetry example 3' shown in Fig. 5, and the knee prosthesis described herein is also applicable to the left knee joint.

Claims (3)

1. knee-joint endoprosthesis is characterized in that:

Femoral prosthesis (1), this prosthese is connected with distal femur, has internal skeleton condyle (1a), dermoskeleton condyle (1b) and intercondylar area territory (1d);

Tibial bearing (5), this bearing is connected with proximal tibia;

Tibia liner (4), this liner are fixed on the tibial bearing (5), have internal skeleton condyle (4a) and dermoskeleton condyle (4b);

Ridge between the tibia condyle (3), in the hole (4c) of packing between tibia liner (4) condyle and in tibial bearing (5) boss (5f) hole, top peripheral is made up of face (3a), (3b), (3c), (3d), (3e), and wherein top peripheral face (3e) is the inclined-plane;

Screw (2) links to each other with the boss (5f) of hole (4c) and tibial bearing (5) between the condyle of tibia liner (4).

2. knee-joint endoprosthesis according to claim 1, it is characterized in that, when knee-expanding position, ridge between the tibia condyle (3) stretches in the intercondylar area territory (1a) of femoral prosthesis, its top peripheral face (3a), (3b), (3c), (3d) match with femoral prosthesis intercondylar area territory (1a), to guarantee the kneed knee joint stability of stretching.

3. knee-joint endoprosthesis according to claim 1, it is characterized in that, it is cut that ridge between the tibia condyle (3) is close to the part of femoral prosthesis (1) dermoskeleton condyle (1b), the top peripheral face (3e) that is ridge between the tibia condyle (3) is the inclined-plane, and top peripheral face (3e) is (B) with the counterclockwise angle of vertical curve (T), guaranteeing that femoral prosthesis (1) has bigger outward turning angle when the enuflex position, thereby increase kneed angle of bend, and finally realize the knee joint deep flexion.

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