Design of the femoral component for cementless hip replacement: the surgeon's perspective

Few guidelines are currently available to the surgeon when choosing a specific femoral component for cementless total hip replacement (THR). A survey of the members of the American Association for Hip and Knee Surgeons (AAHKS) was conducted to gain insight into the importance of implant material, stress shielding, and micromotion in the selection of cementless femoral components. A comprehensive survey was distributed to 300 orthopedic surgeons selected from the members of the AAHKS; 169 of the 300 surgeons completed the detailed questionnaire. The results of the survey were analyzed using the SPSS software package to obtain general trends in opinion, and a stepwise regression analysis was used to correlate responses with training and clinical experience. Interestingly, there was little consensus among surgeons with respect to the relative importance of implant material, stress shielding, and micromotion in the selection of prostheses for cementless THR. In general, bone loss secondary to stress shielding was the least important issue, and axial and rotational micromotion were considered progressively more significant problems. Cementless titanium alloy stems were perceived as offering no significant advantage over cobalt chrome alloy stems. Moreover, there was no consensus as to whether a collar was advantageous. Prosthesis stability, restoration of motion, and a proven clinical record were more important to surgeons than were ease of implantation and removal, cost, and availability.