Fixation of non-cemented total hip arthroplasty femoral components in a simulated proximal bone defect model

摘要

An accelerated sequential proximal femoral bone loss model was used to measure the initial stability of three noncemented femoral stem designs: fully porous-coated, proximally porous-coated, and dual-tapered, diaphyseal press-fit (N. = 18). Only dual-tapered, diaphyseal press-fit stems remained stable with as much as 105. mm of bone loss, with average cyclic micromotion remaining below 25. μm in ML and below 10. μm in AP planes. In contrast, with proximally coated and fully coated stem designs with circular or oval cross-sections, 60. mm of bone loss, resulting in lower than 10. cm of diaphyseal bone contact length, led to gross instability, increasing average cyclic micromotions to greater than 100. μm prior to failure. Therefore, the results provide support for using a dual-tapered stem in revision cases with proximal bone loss.