V-shaped capsular plication for treating cam-type femoroacetabular impingement with hip instability in borderline dysplastic hips: a retrospective cohort study.

Introduction: Purpose Patients with cam-type femoroacetabular impingement (FAI) frequently present with concomitant borderline developmental dysplasia of the hip (BDDH), a critical instability risk factor. Capsular plication may contribute to improved stability through the screw-home mechanism. This study evaluates the clinical outcomes of arthroscopic T-capsulotomy combined with V-shaped capsular plication for managing cam-type FAI in BDDH-associated instability and confirms its short-term efficacy. Methods: This retrospective cohort study included 15 patients diagnosed with symptomatic cam-type FAI and concomitant BDDH (LCEA: 20°-25°) between July 2019 and July 2023. All patients underwent arthroscopic labral repair, femoroacetabular osteoplasty, and T-capsulotomy with V-shaped capsular plication. Clinical outcomes were assessed using the Visual Analog Scale (VAS) for pain, Modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), and Hip Outcome Score Sport-Specific Subscale (HOS-SSS) preoperatively and postoperatively. Statistical analysis employed paired t-tests for intra-group comparisons. Results: All 15 patients completed follow-up with a minimum duration of 12 months (mean 18.2 months, range 12-24). No major complications occurred. Significant improvements were observed in all outcome measures at final follow-up: mHHS improved from 57.33 ± 5.34 to 86.07 ± 2.67 ( Conclusions: The described arthroscopic technique, adapting principles from pediatric DDH surgery, appears to be a promising approach for addressing cam-type FAI in BDDH patients with instability risk factors, demonstrating short-term clinical outcomes. But, further studies with larger cohorts and longer follow-up are warranted.