Capsulectomy vs Capsulotomy With Repair in Direct Anterior Total Hip Arthroplasty

Utilization of the direct anterior approach for total hip arthroplasty (THA) has increased over the last ten years. The approach, as described by Keggi et al, superficially utilizes the internervous muscle plane between the tensor fascia lata and the sartorius and deeply between the rectus and gluteus medius (1). Performing this muscle sparing rather than muscle splitting approach has several purported benefits. The clinical reports of this surgical approach have documented low dislocation rates (2, 3), excellent cup position (4) improved outcome scores (5), less muscle damage (6, 7) and improved gait mechanics (8). The preservation and repair of the anterior hip capsule (iliofemoral and pubofemoral ligaments) has been recommended by some authors, while anterior capsulectomy has been described by other authors without a reported increase in dislocation rate. In contrast, the higher risk of posterior dislocation using the posterior approach improved significantly after repair of the capsule (9, 10). There are no studies to date that have investigated outcome scores based on capsular repair versus capsulectomy for the THA direct anterior approach. The effects of anterior capsular repair versus capsulectomy are unknown with regards to anterior hip pain, range of motion, and surgical recovery. We hypothesize that capsulectomy may allow for reduction in operative time, provide superior surgical exposure, and increased range of motion after surgery. The influence on post operative pain and dislocation rate is unknown. In this prospective, randomized clinical study investigators will compare operative time, blood loss, postoperative pain, range of motion, strength, and adverse events using two different surgical techniques (anterior capsular repair versus anterior capsulectomy) during direct anterior total hip arthroplasty. Patients will be randomized at their screening visit to one of two groups (anterior capsule repair or anterior capsulectomy), and they will be blinded for the group assignment. The surgical procedures will be performed according to the surgeon's routine standard of care.