Hip Arthroscopy Alone for Salvage Treatment of Femoroacetabular Impingement and Concomitant Acetabular Dysplasia Has Poor Outcomes: A Retrospective Case-Control Study

Background: The short-term efficacy of hip arthroscopy as a salvage procedure for acetabular dysplasia and concomitant femoroacetabular impingement syndrome (FAIS) in patients who are not candidates for periacetabular osteotomy remains unclear. Purposes: We sought to compare 2-year patient-reported outcome measures (PROMs) after hip arthroscopy for FAIS (control group) versus FAIS with acetabular dysplasia (dysplasia group) in patients over 40 years of age and/or with mild osteoarthritis (OA). We also sought to measure the rate of subsequent total hip arthroplasty (THA) on the same operative hip. Methods: We retrospectively reviewed prospectively collected data from patients who underwent hip arthroscopy for FAIS by a single surgeon between January 2021 and December 2024. Fourteen patients in the dysplasia group (mean lateral center-edge angle <23°, range 12-32; anterior center edge angle 20°, range 8-25; age 41.5 ± 11.4 years) and 140 controls (mean age 36.0 ± 12.5 years) were included. We analyzed the European Quality of Life – 5 Dimensions-5 Levels, Mental Health Inventory-5, International Hip Outcome Tool-12 (iHOT-12), Physical Function Short Form of the Hip Disability and Osteoarthritis Outcome Score (HOOS-PS), University of California at Los Angeles (UCLA) Activity Scale, Adult Single Item Measure physical activity, Patient-Acceptable Symptoms State (PASS) single item, and subsequent THA on the same operative hip. Results: The dysplasia group demonstrated lower PASS rates, iHOT-12 scores, and HOOS-PS scores compared to controls. THA conversion was higher in the dysplasia group than in the control group (50% vs 5%). In multivariate analysis, dysplasia negatively predicted all outcomes. Intraoperatively identified high-grade cartilage defects predicted THA conversion, but none of the PROMs. Conclusion: This retrospective case-control study suggests that hip arthroscopy alone for FAIS with acetabular dysplasia in patients over 40 years and/or with mild OA may increase the odds of clinical failure compared to arthroscopy for FAIS without dysplasia. High-grade cartilage defects identified intraoperatively were independent risk factors for conversion to THA regardless of dysplasia status. Level of Evidence: Level III: retrospective case-control study.