Does Capsular Closure Affect Clinical Outcomes in Hip Arthroscopy? A Prospective Randomized Controlled Trial

BACKGROUND: There is increasing concern of iatrogenic hip instability after capsulotomy during surgery. Greater emphasis is now being placed on capsular closure during surgery. There are no prospective studies that address whether capsular closure has any effect on outcomes. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate patient outcomes after interportal capsulotomy repair compared with no repair. We hypothesized that restoration of normal capsular anatomy with interportal repair will achieve clinical outcomes similar to those for no repair. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Adult patients with femoral acetabular impingement indicated for hip arthroscopy were randomized into either the capsular repair (CR) or the no repair (NR) groups. All patients underwent standard hip arthroscopy with labral repair with or without CAM/pincer lesion resection. Clinical outcomes were measured via the Hip Outcome Score–Activities of Daily Living (HOS-ADL) subscale, Hip Outcome Score–Sport Specific (HOS-SS) subscale, modified Harris Hip Score (mHHS), visual analog scale for pain, International Hip Outcome Tool, and Veterans RAND 12-Item Health Survey (VR-12). RESULTS: A total of 54 patients (56 hips) were included (26 men and 30 women) with a mean age of 33 years. The HOS-ADL score significantly improved at 2 years in both the NR group (from 68.1 ± 20.5 to 88.6 ± 20.0; P < .001) and the CR group (from 59.2 ± 18.8 to 91.7 ± 12.3; P < .001). The HOS-SS score also significantly improved in both the NR group (from 41.1 ± 25.8 to 84.1 ± 21.9; P < .001) and the CR group (from 32.7 ± 23.7 to 77.7 ± 23.0; P < .001). Improvement was noted for all secondary outcome measures; however, there was no significant difference between the groups at any time point. Between 1 and 2 years, the NR group showed significant worsening on the HOS-ADL (–1.21 ± 5.09 vs 4.28 ± 7.91; P = .044), mHHS (1.08 ± 10.04 vs 10.12 ± 11.76; P = .042), and VR-12 Physical (–2.15 ± 5.52 vs 4.49 ± 7.30; P = .014) subsets compared with the CR group. CONCLUSION: There was significant improvement in the VR-12 Physical subscale at 2 years postoperatively in the capsular CR group compared with the NR group. Capsular closure appears to have no detrimental effect on functional outcome scores after hip arthroscopy. We recommend restoration of native anatomy if possible when performing hip arthroscopy.