FP5.4 Inside-Out Interportal vs Longitudinal Outside-In Capsulotomy in Hip Arthroscopy for Femoroacetabular Impingement: Comparable 2-Year Functional Outcomes Despite Approach Differences

Abstract

Abstract ICLB05 - The Art of Navigation: Foundations of Efficient and Complication-Free Hip Arthroscopy, Session Room 6 (BMCC Level 3), October 8, 2026, 14:00 - 16:00 Introduction Hip arthroscopy for femoroacetabular impingement (FAI) can be performed using either an inside-out interportal capsulotomy (IOIC) or a longitudinal outside-in capsulotomy (LOIC), each with distinct technical characteristics regarding joint access and capsular management. However, the impact of these techniques on mid-term patient-reported outcomes remains unclear. This study aimed to compare 2-year functional outcomes between both techniques. Materials and Methods A retrospective comparative study was conducted including 128 patients undergoing hip arthroscopy for FAI. Patients were grouped according to surgical technique: LOIC (n = 54) and IOIC (n = 74). Baseline comparability was assessed using t-tests, Mann–Whitney U tests, and chi-square tests. Outcomes included HOS-ADL, HOS-Sport, and UCLA scores at 2-year follow-up. Multivariable linear regression was performed to identify independent predictors of outcomes, including age, BMI, preoperative function, and surgical technique. Results Baseline characteristics were comparable between groups, with no significant differences in BMI or radiographic parameters. Patients in the IOIC group were older (42.2 vs 37.5 years, p < 0.05). Surgical time was similar between techniques (119.4 vs 121.8 minutes, p = 0.572). The LOIC group showed a higher number of anchors (2.42 vs 2.09, p = 0.034) and capsular sutures (2.9 vs 2.32, p < 0.001). At 2-year follow-up, both groups demonstrated significant improvement, with no differences between techniques. HOS-ADL scores were 94.4 versus 91.9 (p = 0.627), HOS-Sport scores were 90.3 versus 85.6 (p = 0.576), and UCLA scores were 8.32 versus 9.11 (p = 0.860) for LOIC and IOIC groups, respectively. Multivariable regression identified age (negative β, p < 0.05) and preoperative function (positive β, p < 0.05) as independent predictors of outcomes, while surgical technique was not associated with functional results. Discussion Despite technical differences, both techniques achieved comparable functional outcomes at 2 years. These findings suggest that surgical approach does not determine mid-term clinical results when adequate correction of FAI pathology is achieved. Capsular management appears to depend more on surgical execution than on the selected approach. Conclusion IOIC and LOIC in hip arthroscopy result in comparable functional outcomes at 2 years. Surgical approach does not independently influence clinical results.