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.

Inclusion Criteria:

- Elective unilateral or bilateral primary total hip arthroplasty

- Direct anterior surgical approach

- Osteoarthritis diagnosis

- 18 years of age or older

Exclusion Criteria:

- Revision hip arthroplasty

- Avascular necrosis of the hip

- Rheumatoid arthritis of the hip

- Younger than 18 years of age