The periacetabular osteotomy (PAO) is a well-described procedure for symptomatic acetabular dysplasia. For severe acetabular deformities, the efficacy of acetabular reorientation remains controversial and the literature on mid to long-term outcomes is limited. The purpose of this study was to analyze average 10-year clinical and radiographic results of the PAO for severe acetabular dysplasia.

We retrospectively analyzed a consecutive series of patients undergoing PAO for severe acetabular dysplasia as defined by LCEA < 5˚. Patient demographics, radiographic measurements, modified Harris Hip score (MHHS), UCLA activity, SF-12, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed.

Sixty-eight patients (82 hips; 54 females) with an average age 20.7 and BMI of 24.4 kg/m2 were included. Mean follow-up was follow up was 10.3 years. . The LCEA and ACEA improved a mean of 32.8˚ (8.4˚ to 24.4˚, p<0.0001) and 31.6˚ (−4.9˚ to 26.7˚, p< 0.0001), respectively. MHHS improved an average of 17.5 points (64.6 to 82.3, p<0.0001), WOMAC Pain subscore improved an average of 21.1 points (65.7 to 85.0, p = 0.004), and SF-12 physical improved 11.8 points (from 40.3 to 50.6, p = 0.006). Activity improved as indicated by a 1.5-point increase in the UCLA Activity score (6.4 to 7.9, p=0.005). Six hips (9.1%) converted to THA at average 6.8 years post-PAO. Kaplan-Meier survival analysis with THA as the endpoint was 92% at 15 years (95% confidence interval [CI] (81%–96%). Multivariable linear regression analysis revealed concurrent osteochondroplasty was associated with a decreased risk of PAO failure.

PAO is an effective treatment for severe acetabular dysplasia. At average 10.3 years, clinical and radiographic outcomes demonstrate pain relief, improved hip function, and major deformity correction. We observed minimal clinical deterioration over time.