Neck-Preserving Femoral Stems

Abstract

Surgeons undertaking total hip arthroplasty (THA) routinely perform a distal femoral neck resection. It has been argued that retaining the femoral neck during THA can provide mechanical and biological advantages. The objectives of this study were to review: (1) the current evidence on the advantages of femoral neck preservation during THA and (2) the clinical and radiological outcome of neck-preserving femoral stems. A search of the English-language literature on neck-preserving THA and on the individual neck-preserving implants was performed using PubMed, Ovid SP and Science Direct. Studies have indicated that neck preservation offers superior tri-planar implant stability and allows more accurate restoration of the hip geometry and biomechanics. The trend towards tissue sparing surgery has contributed to the development of bone-conserving short-stem implants that offer variable levels of neck preservation. Despite an initial learning curve, these implants have generated promising early clinical results, with low revision rates and high outcome scores. However, radiological evaluation of some neck-preserving implants has detected a characteristic pattern of proximal femoral bone loss with distal cortical hypertrophy. The long-term implications of this finding are not yet known. Preserving the femoral neck during THA has biomechanical advantages. However, long-term outcome data are needed on neck-preserving femoral stems to evaluate on-going bone remodelling and assess implant performance and survival.