Failure assessment of hip stem due to pelvic positioning and femoral stem loosening

Abstract

AbstractThe hip joint is subjected to different loads, leading to hip stem failure from the crack nucleation to the final implant failure. The main objective of the present work is to assess hip stem damage due to pelvic positioning and femur movement. The three‐dimensional finite element analysis (3D FEA) was created to simulate the artificial hip joint subjected to static or cyclic loading. The fatigue crack growth rate in the hip stem was investigated based on the extended finite element method (XFEM) with the cycle fatigue approach. The femoral stem loosening during adduction and abduction movements, which may have occurred, was considered. The numerical results showed that the von Mises stress value increases as the loosening distance increases, which appears with the decrease of the cup positioning angle. Furthermore, the pelvic positioning does not affect the crack initiation site, while the loosening and femur movement affect the crack initiation site. On the other hand, the fatigue crack growth rate was affected by pelvic positioning, loosening, and femur movement.