EP1.69 Learning curve in periacetabular osteotomy: a single-center retrospective study

Abstract

Abstract Introduction Periacetabular osteotomy (PAO) is a technically demanding procedure with a recognized learning curve in hip preservation surgery. Objectives To determine the number of PAO procedures required to reach a plateau in operative time, and to assess the number of cases needed to achieve adequate radiographic correction based on LCEA, AWI, and PWI. Methods A retrospective analysis of 110 hips was performed. Two surgical approaches (Smith-Petersen and Bikini) were used with intraoperative fluoroscopy. Radiographic evaluation was performed pre- and postoperatively by two observers. CUSUM analysis and LOWESS smoothing were applied to assess the learning curve and radiographic outcomes. Results The cohort included 110 hips (89.1% female), with a mean age of 31.5 ± 9.4 years and mean BMI of 24.2 ± 3.81. Mean hospital stay was 4.34 ± 2.20 days. Preoperative LCEA and Tönnis angle averaged 19 ± 5.75 and 14.94 ± 7.5, respectively. CUSUM analysis identified a peak at case 32, followed by a significant reduction in operative time. Operative time decreased from 142.1 ± 31 minutes in the learning phase to 87.2 ± 23 minutes in the proficiency phase (p < 0.001). Complication rates were significantly lower in the proficiency phase (10.3% vs 43.8%, p < 0.001). Radiographic correction remained consistent across all cases, with no significant differences between phases. Conclusions The PAO learning curve demonstrates a significant improvement in operative efficiency after approximately 32 cases, with a plateau reached around case 80. Radiographic correction is achieved consistently from early cases, suggesting that surgical experience improves efficiency without compromising accuracy.