Abstract:
This study investigates the biomechanical propensity for fracture propagation in ceramic liners used in total hip arthroplasty (THA) under conditions of impingement-subluxation. Due to the brittle nature of ceramic materials, these liners are susceptible to fracture under stress concentrations caused by certain hip motions and surgical implant orientations. Employing a sophisticated finite element (FE) modeling framework, the authors developed and validated a fracture mechanics model specifically designed to evaluate how variations in implant orientation, such as cup inclination and anteversion, affect liner vulnerability. Simulations of various common patient maneuvers including squatting, stooping, and shoe-tying identified these activities as particularly high-risk scenarios for liner fracture. Results clearly demonstrated that increased cup inclination and anteversion significantly elevate stress concentrations, thereby increasing fracture risk. The computational analyses also identified specific regions within the ceramic liners highly susceptible to crack propagation under dynamic loading conditions. This biomechanical investigation provides critical insights into how implant positioning and patient activities influence ceramic liner fracture risk, highlighting the importance of optimized surgical techniques and patient guidance to mitigate these risks.
