Prevention and Treatment of Limb-Length Discrepancy in Total Hip Arthroplasty

Abstract

The prevention of leg-length discrepancy after total hip arthroplasty requires a careful patient history, physical examination, and radiographic assessment. When the source and amount of preoperative leg-length discrepancy are understood, a careful preoperative plan can be designed to restore leg-length equalization. Intraoperative execution of the preoperative plan requires a systematic approach that depends partly on the chosen surgical approach. The use of the anatomic landmarks, intraoperative calipers, intraoperative radiographs, computer-assisted navigation, and robotic-assisted surgery all have excellent published results for restoring accurate leg lengths postoperatively. Some preoperative leg-length differences cannot be restored due to risk of nerve injury or hip stability and the patient should be counseled preoperatively to avoid postoperative patient dissatisfaction. Most postoperative leg-length discrepancies (between 5 mm and 1 cm) will not be noticeable to patients at 1 year postoperatively. Patients who remain symptomatic can usually be treated with a shoe insert to equalize leg lengths. In rare instances, a symptomatic patient may be unsatisfied with shoe inserts and revision surgery can be performed. Shortening of the operative limb can be performed with femoral head exchange or acetabular component revision. The discrepancy can also be addressed with a distal shortening femoral osteotomy. If the patient has contralateral hip osteoarthritis, planned lengthening can also be performed at time of subsequent total hip arthroplasty. This chapter outlines several techniques to help minimize an unexpected postoperative leg-length discrepancy and describes the treatment of symptomatic leg-length inequality.