Use of modular femoral stem combined with large diameter femoral head in alumina-on-alumina total hip arthroplasty

Abstract

While the clinical use of alumina-on-alumina bearings in total hip arthroplasty has demonstrated excellent clinical results with a low rate of osteolysis, relatively few head and liner options of alumina implants compared with conventional metal-on-polyethylene articulations continue to be one potential disadvantage that may often lead to impingement or dislocation after total hip arthroplasty. We hypothesized that a modular femoral stem that offered a variety of intraoperative adjustment options for producing appropriate femoral offset, length, and version would be favored to optimize stability following alumina-on-alumina total hip arthroplasty. It was also postulated that larger diameter femoral heads that allow for a greater range of motion prior to prosthetic impingement could reduce the risk of dislocation following alumina-on-alumina total hip arthroplasty. When reviewing a consecutive series of 136 alumina-on-alumina total hip arthroplasties performed with use of the S-ROM modular stem combined with 32-mm femoral head at our institution, we have found no ceramic fractures or bearing failures, and only one early postoperative dislocation that resolved with closed reduction was identified during the short follow-up period. Given the extremely low wear rates of alumina-on-alumina bearings even with larger femoral head diameters, our findings may increase potential for use of 32-mm femoral head combined with the S-ROM modular stem in both straightforward and complex total hip arthroplasties that are at high risk for prosthetic impingement or dislocation.