A volumetric wear evaluation method for polyethylene liner of artificial knee joint

Abstract

An artificial knee joint polyethylene liner volume wear evaluation method disclosed by the present invention comprises a volume wear data measurement step and a volume wear amount calculation step, and the volume wear data measurement step comprises utilizing a UV scanning command in a measurement software to generate a touch measurement path and a touch measurement vector automatically based on the prosthesis model characteristics. According to the present invention, by the iteration, more accurate theoretical values can be provided to the machines, thereby obtaining the more accurate measurement results; by utilizing the measurement data before wear and the data after wear to optimize, the influence of a measurement error on a volume calculation result is reduced furthest; at the same time, by optimizing an original Delaunay triangulation algorithm, a more ideal triangulation result is obtained, and further a single time volume calculation result is more accurate. A measurement method used in the present invention enables the repeated measurement precision of a volume analysis method and the accuracy of the calculated volume wear amount to be improved.

Description

technical field [0001] The invention is applicable to the field of friction and wear of artificial knee joints, and in particular relates to a method for evaluating the volume wear of polyethylene liners of artificial knee joints. By optimizing the measurement process, measurement results and calculation programs, the accuracy of the obtained volume wear amount is improved. Background technique [0002] In the artificial knee joint wear test in vitro, a measurement method is needed to give the wear amount of the artificial knee joint liner during the experiment, and then evaluate the wear performance of the knee joint prosthesis product. The knee prosthesis mainly consists of two parts: the femoral condyle and the tibial liner. Compared with the femoral condyle made of cobalt-chromium-molybdenum alloy, the tibial liner made of ultra-high molecular weight polyethylene is more prone to wear and damage. International standards have stipulated a wear measurement method for arti...

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Problems solved by technology

[0003] However, there are some unavoidable problems affecting the accuracy of the results in the gravimetric analysis method: first, the water absorption of the ultra-high molecular weight polyethylene liner will lead to an increase in its own mass; Pad, ultrasonic cleaning is also difficult to remove; again, changes in ambient temperature and humidity during the weighing process will affect the weighing results

However, due to the complex shape of the artificial knee joint liner relative to the surface of the hip joint cup, it is difficult to measure, and the measurement repeatability is low. Therefore, the international standard has not given a volume analysis method for the measurement of artificial knee joint wear in vitro.

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