Paper 38: Closing the gap: two-year outcomes after arthroscopy and periacetabular osteotomy for femoroacetabular impingement syndrome with hip dysplasia match those of non-dysplastic peers

Objectives: Femoroacetabular impingement syndrome (FAIS) is commonly managed with hip arthroscopy, yielding excellent outcomes in most patients. However, the presence of acetabular dysplasia with more than borderline undercoverage has been associated with poorer results when arthroscopy is performed in isolation. In such cases, a combined approach-addressing intra-articular pathology with arthroscopy and correcting acetabular deficiency with periacetabular osteotomy (PAO)-has shown promise. This study aimed to compare 2-year patient-reported outcomes between patients with FAIS and hip dysplasia treated with staged hip arthroscopy followed by PAO and patients with FAIS without dysplasia treated with arthroscopy alone. We hypothesized that dysplastic patients undergoing combined arthroscopy and PAO would achieve outcomes comparable to non-dysplastic patients undergoing arthroscopy alone.
Methods: We prospectively collected data on patients undergoing hip arthroscopy for FAIS (January 2021-April 2023) by a single surgeon were retrospectively reviewed. Dysplasia was defined by lateral or anterior center-edge angle <20°; all such patients underwent staged PAO and hip arthroscopy. The primary outcomes were International Hip Outcome Tool (iHOT-12) score and Patient Acceptable Symptom State (PASS) achievement at 2 years. Secondary measures included EQ-5D-5L, Mental Health Inventory-5 (MHI-5), Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS), UCLA Activity Scale, Adult Single Item Measure physical activity, and revision rates. Group comparisons used bivariate tests and forward-selection multivariate regression adjusting for baseline differences.
Results: Of 147 included patients, 23 had staged arthroscopy and PAO for dysplasia (mean age 27.9 +- SD 8.7 years; 95.7% female) and 124 were non-dysplastic and underwent hip arthroscopy alone (36.3 +- 12.8 years; 80.6% female). Dysplastic patients were younger, more often female, and less likely to have had preoperative corticosteroid injection (all p<0.05) (Table 1). At 2 years, iHOT-12 scores (67.2 +- 29.8 vs. 62.1 +- 30.5; p=0.45) and PASS rates (69.6% vs. 54.8%; p=0.18) did not differ (Table 2). No significant group differences were found for EQ-5D-5L (p=0.12), MHI-5 (p=0.78), HOOS-PS (p=0.39), UCLA (p=0.24), or Adult SIM PA (p=0.08) (Table 2). Revision surgery rates (21.7% vs. 14.5%; p=0.40) and complication rates (4.3% vs. 4.8%; p=0.76) (Table 2) were also similar. In multivariate analysis, dysplasia was not an independent predictor of any outcome.
Conclusions: Staged arthroscopy with subsequent PAO for patients with FAIS and hip dysplasia produced 2-year outcomes statistically indistinguishable from non-dysplastic patients treated with arthroscopy alone. To our knowledge, this is the first comparative study to show that correcting dysplasia with PAO in addition to arthroscopic FAIS management can fully close the outcome gap traditionally observed between dysplastic and non-dysplastic hips.