Advance in the Bio-Mechanical and Bio-Tribological Evaluation of Hip Prosthesis

The hip joint is the largest and most stable load-bearing joint in the human body. Joint damage or disease often limits its function, which seriously affects life quality. With the aging process and the increase in the amount of young patients, higher requirements are placed on the function and performance of hip prostheses. To speed up the rehabilitation process, prolong the service life of orthopedic implants, and eliminate or reduce the possibility of future revisions, the joint prosthesis needs a careful preclinical evaluation before it is put on the market, that is, to evaluate the safety and effectiveness of the artificial joint prosthesis. Because, they present a significant inherent potential for hazards. Thus, safety and effectiveness are always the most important considerations before clinical application. The performance evaluation of artificial hip prosthesis is related to its loading condition in the human body. Artificial hip prostheses are often subjected to complex loads, movements, and human body fluid environments in vivo. The construction of complex environments for the investigation on the service behavior of the artificial hip joint prosthesis in vivo is conducive to reducing the failure of the prosthesis and improving patient satisfaction. Through literature research, this paper expounds on the relevant evaluation standards and methods of hip prostheses, points out the limitations of the existing evaluation methods, and proposes future improvements. For the evaluation of materials used in joint prostheses, relevant institutions have formulated a series of standard procedures to evaluate their mechanical and tribological characteristics, but further research is needed for the performance evaluation of porous materials. The mechanical and tribological evaluations of artificial hip joint components have formed relevant testing standards, but most of them are too simplified, and some of the other evaluation measures are still in the stage of laboratory research. There are no relevant evaluation and test standards for the biomechanical performance and movement function evaluation on the artificial hip joint prosthesis, and some exsiting approaches are all in the stage of laboratory research. Among them, there are many studies on performance/function evaluation, but the motions and loads used in the research are different from the real in vivo environment. In addition, different patient-specific factors, such as male and female, old and young, height and short, fat and thin, different prosthesis size, different prosthesis design, and other factors, also influence the in vivo mechanical environment of the artificial hip prosthesis. Therefore, it is of great significance to the development of preclinical evaluation of orthopedic implants by establishing a systematic and hierarchical hip prosthesis evaluation system, applying the loads which is equivalent to loading conditions of the prosthesis in vivo, and coupling the interaction among various influencing factors.