Comparison of specific femoral short stems and conventional-length stems in primary cementless total hip arthroplasty

There are several reported disadvantages with conventional-length femoral stems in cementless total hip arthroplasty (THA). Therefore, various efforts have been made to develop a specific femoral short stem to improve physiologic bone remodeling at the femoral aspect of a cementless THA. However, there are potential disadvantages with specific femoral short stems, such as malalignment, inadvertent subsidence, and potential proximal femoral fracture. Therefore, the authors quantitatively compared radiographic and clinical outcomes as well as component-specific complications between 2 groups of patients following primary cementless THA. A matched comparison was made between specific femoral short stems (n=50) and conventional- length femoral stems (n=50) in cementless THA procedures performed between January 2008 and January 2012. Patients were matched for age, sex, body mass index, height, surgical approach, and surgeon. No significant differences were found between the 2 groups in mean postoperative radiographic outcomes, functional outcomes, or complications. Both groups showed satisfactory performance at 5-year follow-up. Specific femoral short stems resulted in a higher incidence of malalignment and subsidence and a lower incidence of thigh pain and proximal bone resorption compared with conventional-length femoral stems. Although longer follow-up is required, specific femoral short stems may have clinical and radiographic advantages with equivalent perioperative complications relative to conventional-length femoral stems. However, this technique requires proper patient selection in combination with careful preoperative planning and meticulous surgical technique.