Arthroscopic Capsular Repair for Symptomatic Hip Instability After Previous Hip Arthroscopic Surgery

Background: Management of the hip capsule has been a topic of recent debate in hip arthroscopic surgery. Postoperative instability after hip arthroscopic surgery has been reported and can lead to poor outcomes.

Purpose: To determine the outcome of patients diagnosed with symptomatic instability after hip arthroscopic surgery at a minimum of 12 months and 24 months after revision surgery for capsular repair.

Study design: Case series; Level of evidence, 4.

Methods: In a cohort of approximately 1100 patients who underwent hip arthroscopic surgery, 33 patients (33 hips) developed symptomatic instability requiring a revision surgery. Two patients suffered anterior dislocations following their initial surgery. Radiographs were reviewed to evaluate for acetabular dysplasia. Three patients were lost to follow-up and 10 patients were excluded as they were <1 year out from the revision surgery. A total of 20 patients (18 female, 2 male) completed a preoperative and postoperative modified Harris Hip Score (mHHS) and Hip Outcome Score (HOS) at a minimum of 12 months. Eleven of these patients had a minimum follow-up of 24 months. All patients filled out a Likert scale of perceived improvement in physical ability at final follow-up.

Results: The mean age of the patients was 29.7 years (range, 15.2-55.5 years). The mean lateral center-edge angle was 25°, and the mean acetabular index was 7° before revision. All patients underwent interportal capsulotomy during the index arthroscopic procedure. After their index arthroscopic procedures, patients had minimal improvement at a mean of 19.1 months postoperatively on the mHHS (from 57.1 to 57.6; P = .423), HOS-Activities of Daily Living (ADL) (from 62.7 to 66.4; P = .260), and HOS-Sports (from 42.0 to 39.1; P = .800). For the patients with a minimum 1-year follow-up after revision surgery (n = 20; mean follow-up, 21.3 months), the mean mHHS (from 57.6 preoperatively to 85.8 at final follow-up; P < .001), HOS-ADL (from 66.4 to 85.7; P < .001), and HOS-Sports (from 39.1 to 79.8; P < .001) all improved significantly. The results were similar when looking at only the patients with a minimum 2-year follow-up after revision surgery (n = 11; mean follow-up, 26.1 months); the mean mHHS (from 56.0 preoperatively to 91.5 at final follow-up; P = .001), HOS-ADL (from 68.3 to 89.9; P = .009), and HOS-Sports (from 35.7 to 87.9; P = .001) all improved significantly. When comparing patients with isolated capsular repair to those with additional procedures performed, there were no differences between the groups (all P > .05). At final follow-up, all but 1 patient had improved overall physical ability levels.

Conclusion: Revision hip arthroscopic surgery for capsular repair in patients with symptomatic instability after hip arthroscopic surgery provides good functional outcomes at a minimum of 1 and 2 years postoperatively.