Learning curve in periacetabular osteotomy for developmental dysplasia of the hip : a systematic review and meta-analysis.

Aims: Periacetabular osteotomy (PAO) is technically demanding with an assumed steep learning curve. This systematic review and meta-analysis evaluated how surgeon experience influences operative efficiency, perioperative morbidity, radiological correction, and conversion to total hip arthroplasty (THA) in developmental dysplasia of the hip (DDH). Methods: A systematic search of five databases identified studies comparing early with late PAO experience phases. Random-effects meta-analyses (Sidik-Jonkman with Hartung-Knapp adjustment) were performed for continuous (mean difference (MD)) and binary (odds ratios (ORs)) outcomes. Risk of bias was assessed with Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I), and certainty of evidence with Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results: In all, seven studies (499 patients, 556 hips) were included. Late-phase PAOs had significantly shorter operative times (MD -74.58 minutes, 95% CI -136.52 to -12.65). No significant differences were found for blood loss, complications, THA conversion, or radiological correction. Heterogeneity was high for operating time and blood loss, and most studies showed moderate risk of bias. Conclusion: Surgeon experience substantially improves operative efficiency in PAO, while complications, blood loss, radiological accuracy, and early THA conversion appear largely unaffected, likely reflecting structured supervision and high-volume training environments. The lack of significant differences in complications and radiological correction suggests that structured mentorship and centralized hip preservation programmes may mitigate early-phase risk. Standardized, prospective studies are needed to define proficiency thresholds and optimize training in hip preservation surgery.