The Effect of Total Hip Arthroplasty Surgical Technique on Postoperative Muscle Atrophy

A variety of surgical approaches are used for total hip arthroplasty (THA). Controversy still exists regarding whether the direct anterior approach truly minimizes muscle damage. The purpose of this study was to determine the effect of surgical approach for THA on muscle atrophy quantified through magnetic resonance imaging (MRI). The study included 25 hips in patients with a mean age of 64.72±8.35 years who underwent a primary unilateral THA for severe osteoarthritis. Patients were grouped according to surgical approach: direct anterior (n=9), direct lateral (n=9), and posterior (n=7). Magnetic resonance images were collected at the 24-week postoperative time point to assess atrophy/fatty infiltration of the hip musculature. All MRIs were assessed by a fellowship-trained radiologist who was blinded to all clinical information. There were no significant differences preoperatively and 1 year postoperatively between the surgical approach groups in terms of patient-reported outcome measures (P>.05). Significant differences in fatty infiltration differences between surgical approaches were observed in the gluteus medius, gluteus minimus, iliacus, obturator externus, obturator internus, pectineus, psoas, quadratus femoris, sartorius, and vastus intermedius (P<.05). The direct anterior approach to THA resulted in less atrophy of the hip musculature compared with a direct lateral or posterior approach; however, there were no differences in patient-reported clinical outcome scores at 1 year between the surgical approaches. [Orthopedics. 2020;43(6):361-366.].