Femoral version: definition, diagnosis, and intraoperative correction with modular femoral components.

Normal femoral version contributes to the inherent stability of the hip joint. Abnormal version is found in a variety of hip diseases afflicting children and adults. At the time of reconstruction for end-stage hip disease, maintaining proper femoral version in conjunction with acetabular version allows for hip stability and unimpeded functional range of motion. In those instances where femoral version is significantly abnormal, a means of correction at time of surgery is necessary. Non-modular femoral components allow for minor adjustments in version at time of surgery. To accommodate significant versional abnormalities, the modular S-ROM (DePuy Orthopaedics Inc, Warsaw, Ind) was introduced in 1984. In a series of 156 primary S-ROM total hip arthroplasties, the ability to correct for abnormal version resulted in excellent clinical results with no incidence of hip instability and excellent range of motion.