FP2.6 Impact of Prior Failed Arthroscopy on Patient-Reported Outcomes After Combined Hip Arthroscopy and Periacetabular Osteotomy for Borderline Hip Dysplasia

Abstract

Abstract ICLA02 - Demystifying the Deformed Hip: Practical Principles of Pelvic and Femoral Osteotomies, Auditorium A (BMCC Level 1), October 8, 2026, 10:30 - 12:30 Background Borderline hip dysplasia (BLD) presents a clinical dilemma, as the optimal surgical strategy remains unclear. Treatment options include isolated hip arthroscopy, periacetabular osteotomy (PAO), or a combined approach. When isolated arthroscopy fails, it is unknown whether subsequent combined hip arthroscopy and PAO can achieve comparable patient-reported outcomes (PROs) to primary combined treatment. This study compared PROs between BLD patients undergoing combined hip arthroscopy and PAO after failed prior isolated arthroscopy versus those treated with primary combined surgery. Methods A retrospective review was performed of BLD patients (lateral center-edge angle [LCEA] 18–25°) who underwent combined hip arthroscopy and PAO at a single institution. Arthroscopy was performed within 30 days of PAO. Patients were stratified into two groups: (1) Failed Scope (prior failed isolated arthroscopy) and (2) Direct Scope+PAO (primary combined treatment). The primary outcome was the International Hip Outcome Tool-12 (iHOT-12) at minimum 2-year follow-up. Achievement of minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were assessed as secondary outcomes. Demographics, Beighton laxity score, and radiographic parameters were compared to evaluate baseline comparability. Statistical significance was set at p<0.05. Results A total of 134 hips were included (20 Failed Scope, 114 Direct Scope+PAO). Groups were comparable in age, sex, Beighton laxity score, LCEA, and sourcil angle (p>0.05). Radiographic correction following PAO was similar between groups. Both groups demonstrated significant improvement in iHOT-12 at a mean 2-year follow-up (Failed Scope: 37.9 to 69.5; Direct Scope+PAO: 43.0 to 79.1; p<0.001 for both). The magnitude of improvement was substantial in both groups (Δ31.6 vs. Δ36.1). A higher proportion of Direct Scope+PAO patients achieved MCID (74.3% vs. 68.0%) and PASS (77.6% vs. 64.0%), though these differences were not statistically significant. Conclusions Combined hip arthroscopy and PAO yields clinically meaningful improvement in patient-reported outcomes for BLD patients, even after failed prior isolated arthroscopy. However, primary combined treatment trended toward higher rates of achieving MCID and PASS, suggesting that early consideration of PAO in the BLD population may optimize clinical outcomes.