Techniques in the Development of a Lower Weight Medical Implants and Strength Validation Using Finite Element Methods

Abstract

Artificial knees have been used in total knee arthroplasty for more than 6 decades. The major drawback of the medical implant is its weight, with the average weight of an artificial knee implant made of stainless steel and ultra-high-molecular-weight polyethylene being approximately 450 g. Tne weight of the natural knee removed during arthroplasty is < 70 g. Thus, the increase in weight is approximately 600 percent, which causes muscle fatigue and decreased knee functionality. Our research aimed to develop an artificial knee implant, in which the design is modified and corrected to make the implant weigh less. The implant weight was reduced by drilling holes in thicker areas of the implant. The radius of the drill holes and their length inside the implant were controlled by conducting simulation studies using finite element modelling (FEM) techniques. These effects of using drills on implants reduced the implant weight to approximately 25 g. Performance was validated by loading the implants to 2000 N, which is approximately 15x the average body weight, and showed satisfactory results in weight reduction and performance of the new implant models.