The effectiveness of dual offset stems in restoring offset during total hip replacement

Commonly, total hip prostheses have had a higher neck-shaft angle than the host bone and thus a tendency to reduce the femoral offset. Restoration of the femoral offset may be important as it has been shown to enhance hip stability and to improve the range and strength of abduction. The purpose of this study was to determine which of two designs was best able to restore femoral offset in comparison to the contralateral normal hip. Two hundred and two primary total hip patients were included in a radiographic study. Measurements were taken from a postoperative anteroposterior radiograph of the pelvis. The Synergy femoral component with a more varus neck-shaft angle of 131 degrees and a standard or high offset option tended to restore the femoral offset more reliably than did the Mallory-Head femoral component with a neck shaft angle of 135 degrees.