The Importance of Range of Motion after Total Hip Arthroplasty

Unlike the knee, range of motion has been of questionable value in evaluating clinical outcome after THA. We retrospectively analyzed the ranges of motion (flexion, abduction, adduction, external rotation, internal rotation, and flexion contracture) of 1383 patients (1517 hips) having primary THA. We recorded Harris hip score components for walking distance, stair climbing, socks and shoes, sitting, pain, presence of limp, and use of support devices. Postoperative hip motion was defined as high (115° of flexion, 25° of abduction, 20° of external rotation, and less than 20° of flexion contracture), average (90°-114° of flexion, 16°-24° of abduction, or 11°-19° of external rotation, and less than 20° of flexion contracture), or low (less than 90° of flexion, 15° or less of abduction, 10° or less of external rotation, or 20° or more of flexion contracture) motion. We correlated this with high, average, or poor postoperative Harris hip scores. Hip motion was found to be correlated with postoperative hip function and may be more useful than previously thought in evaluating hip outcome.

Level of Evidence: Level IV, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.