A Polymer-based Femoral Stem Implant: Finite Element Analysis Study

Over the decades, hip replacement has proven successful, although extending the life of implants and, above all, solving the problems associated with implantation remain crucial. In particular, particle deposits that form due to wear of the prosthesis and enter the biological environment or the risk of bone mass loss resulting from improper load transfer represent ongoing challenges. Among the various types of femoral components available in clinics, numerous hip prostheses made from combinations of metals, ceramics, and polymers have been explored. However, there are insufficient studies for polymer-based femoral stem implant. This study proposed the effectiveness of a press-fit hip implant with a carbon-reinforced PEEK femoral stem coated with hydroxyapatite and an alumina-on-alumina bearing. The mechanical parameters of the hip prosthesis model were verified by static finite element analysis, which considered stress, displacement, deformation, and factors of safety. The presented design demonstrated theoretical feasibility as the elastic modulus of the polymer in the current study is closer to the bone than traditional metals, resulting in smoother load transfer and subsequently eliminating stress shielding and micromotion at the bone-implant junction. Based on the initial analysis, the results appeared to be satisfactory.