Bipolar head prosthesis

Abstract

The invention discloses a bipolar head prosthesis, which comprises a big head, a ball head and a locking ring, wherein the big head is of a cup-shaped spherical structure; a cavity for arranging femoral components is arranged in the ball head; the ball head is put in the big head; the outer wall of the ball head is close to the inner wall of the big head; and the inner wall at the opening part of the big head is locked with the outer wall of the ball head through the locking ring. The bipolar head prosthesis is simple in structure, is not easy to dislocate, can be implanted stably and convenient in operation, is favorable to reducing the abrasion and prolonging the service life, enables the moving range of a hip joint to be increased, and is more practical.

Description

technical field [0001] The invention relates to a surgical implant replacing the femoral head of the hip joint, in particular to a bipolar head prosthesis. Background technique [0002] A bipolar prosthesis is a surgical implant used to replace the femoral head of the hip. It is used in combination with a femoral stem for hip hemiarthroplasty. The existing bipolar head prosthesis structure is mainly a compression structure, which is composed of an outer cup, an inner liner and a ball head. The material of the outer cup and the ball head is CoCrMo, and the material of the inner lining is ultra-high molecular weight polyethylene. The outer cup and the inner liner are matched in a taper, and there are longitudinal grooves around the inner liner to facilitate the retraction of the inner liner when the outer cup and the inner liner are installed (such as Figure 1-4 shown). [0003] Although the above-mentioned bipolar head prosthesis can replace part of the articular surface ...

AI Technical Summary

Problems solved by technology

[0003] Although the above-mentioned bipolar head prosthesis can replace part of the articular surface of the hip joint and femur, it is indeed progressive, but in actual use, it is found that there are still some shortcomings in its structure, which causes the bipolar head prosthesis to be ineffective in practical applications. , failed to achieve the best use effect, and its shortcomings can be summarized as follows:

[0004] 1. It is not easy to install. It takes a lot of thrust to install the inner lining and outer cup, and the dimensional accuracy of the polyethylene lining is high, and the processing characteristics of the polyethylene material itself cannot guarantee high dimensional accuracy.

It is not strong enough and stable, and there is a danger of falling out of the inner and outer cups and inner lining after long-term use in the future

[0005] 2. The wear is serious, and the wear involves two articular surfaces, one is the articular surface composed of the human physiological acetabulum and the CoCrMo outer cup of the bipolar head prosthesis, because the outer cup of the bipolar head prosthesis with this structure is thin-walled structure, its shape is easily deformed, and the geometric roundness of the shape can only be guaranteed at about 100 μm, and the lower spherical roundness of the shape increases the wear and tear with the human physiological acetabulum

Due to the processing characteristics of polyethylene, the roundness of the articular surface of the inner lining cannot reach a high level, and the inner lining is easily deformed during the installation process of the inner lining and the outer cup, which makes the spherical roundness of the inner lining articular surface even more unsatisfactory Yes, the wear is more severe, resulting in a large amount of polyethylene fragments leading to osteolysis, loosening of the prosthesis, and eventually having to undergo revision surgery

[0006] 3. The range of motion is small. Due to the influence of this structure, the range of motion of this bipolar head is only about 25 degrees, which will greatly increase the wear and tear of the human physiological acetabulum, and will also cause serious adverse consequences for future revision operations

[0007] The existing bipolar head prosthesis obviously still has inconvenience and defects in structure and use, and needs to be further improved urgently

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