FP2.3 Outcomes of Combined Hip Arthroscopy, Periacetabular Osteotomy, and Derotational Femoral Osteotomy for Complex Hip Instability Associated With Dysplasia and Abnormal Femoral Torsion

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 The optimal management of complex hip instability remains challenging, particularly in patients with combined acetabular dysplasia and abnormal femoral torsion. While hip arthroscopy (HA) and periacetabular osteotomy (PAO) effectively address intra-articular pathology and acetabular under coverage, persistent instability may occur when femoral torsional abnormalities are not corrected. A comprehensive approach incorporating HA, PAO, and derotational femoral osteotomy (DFO) may better restore hip stability in this patient population, however, clinical outcomes following this combined strategy have not been well defined. Methods A retrospective review was performed of patients undergoing combined HA, PAO, and DFO for symptomatic hip instability at a single academic institution. Inclusion criteria were hip dysplasia (lateral center-edge angle [LCEA] <25°) and abnormal femoral torsion (≥35° or ≤0°, measured using Murphy’s method), with a minimum 2-year follow-up. Demographics, Beighton score, and radiographic parameters (LCEA, Sourcil angle, femoral torsion) were collected. Hip range of motion at 90° flexion (flexion, external rotation, internal rotation, abduction) was recorded pre- and postoperatively. Clinical outcomes included the International Hip Outcome Tool–12 (iHOT-12) and Non-Arthritic Hip Score (NAHS). Achievement of minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) was assessed. Statistical significance was set at p < 0.05. Results Fifty-two patients (55 hips) were included with a mean follow-up of 42 months. Mean age was 29 years, 84% were female, and mean Beighton score was 3.8. Significant radiographic correction was achieved, with LCEA improving from 19.4° to 38.3° and Sourcil angle from 11.1° to −0.7° (p < 0.001 for both). Mean preoperative femoral torsion for excessive antetorsion was 44.2° (range, 35-73°), and -3.9° (range, 0- [-20°]) for excessive retrotorsion. Internal rotation at 90 degrees of hip flexion decreased from 35.4° preoperatively to 15.9° postoperatively (p < 0.001). Significant improvements were observed in iHOT-12 (27.3 to 76.6; p < 0.001), with 82% achieving MCID and 77% achieving PASS. NAHS improved from 49.9 to 83.1 (p < 0.001), with 80% achieving MCID and 68% achieving PASS. Conclusion Combined HA, PAO, and DFO provides significant clinical and radiographic improvement in patients with complex hip instability due to dysplasia and abnormal femoral torsion at midterm follow-up. High rates of clinically meaningful improvement were observed, supporting this multiplanar approach as an effective treatment strategy for this challenging patient population.