Finite Element Study on the Effect of Acetabular External Edge Defect on the Initial Stability Of Acetabular Prosthesis
Objective To explore the critical condition of initial stable acetabular defect in total hip arthroplasty(THA)by using three-dimensional finite element method.Methods The three-dimensional pelvic model was reconstructed by computer software,and different external defects of acetabulum were designed.The coverage rate of acetabulum cup under different defect models and the critical frettage displacement of acetabulum cup relative to host bone were calculated.Results When α=-25 °,the maximum displacement of acetabulum relative to host bone was 39 μm,and the acetabulum coverage was 67.1%,which reached the critical value of acetabulum stability.Conclusion During total hip replacement with biological prosthesis,the bone coverage of the acetabular cup should be maintained at least 67.1%without additional fixation to ensure the initial stability of the acetabular cup implantation with normal gait.