The influence of PEEK acetabular shell on the mechanical stability of total hip replacements under gait loading and motion

The demand for total hip replacement surgery is increasing year by year. However, the issue of hip prosthesis failure, particularly the modular acetabular cup, still exists. The performance and functional requirements of modular acetabular cups have not yet met clinical expectations. This study focused on poly-ether-ether-ketone (PEEK) shells, using finite element methods to investigate their mechanical stability under gait loads and motion, including parameters such as deformation, micromotion, and bone strain. The results showed that a compromise was required among the mechanical performance, stability, and bone integration capabilities of the PEEK shell. As the shell rigidity increased, deformation decreased. However, increased rigidity also increased micromotion at the bone-prosthesis interface, reducing the area that promoted bone ingrowth. Additionally, potential bone absorption areas were also increased, reducing bone preservation and reconstruction capabilities. Compromises need to be made among mechanical performance, stability, and bone integration to achieve optimal mechanical stability. In this study, a 6 mm wall thickness PEEK shell was found to provide good overall mechanical stability.