Periacetabular osteotomy versus hip arthroscopy in patients with borderline developmental dysplasia of the hip: A systematic review and multi-level meta-analysis

PurposeA comprehensive meta-analysis is required to address the lack of quantitative evidence on treatment outcomes in borderline developmental dysplasia of the hip (BDDH). This study compares periacetabular osteotomy (PAO) and hip arthroscopy (HAS) through a multi-level meta-analysis, providing quantitative insights into their efficacy and safety.MethodsA systematic literature search was conducted in PubMed, Epistemonikos, and Embase up to February 28, 2025. A frequentist meta-analysis was performed using the Hartung-Knapp-Sidik-Jonkman heterogeneity estimator. Continuous variables were analyzed using mean values with 95% confidence intervals (CIs), and binary outcomes as proportions with 95% CIs. Sensitivity analysis compared studies defining BDDH as 20-25 degrees versus all included studies. Statistical heterogeneity was assessed using Higgins' I2. A random-effects model was applied in cases of significant heterogeneity.ResultsThe literature search identified 39 primary studies with a total of 2075 patients (2121 hips). The test for subgroup differences showed no statistically significant difference between the PAO group and the HAS group in post-operative mHHS (chi 2 = 0.55; df = 1; p = 0.46), in post-operative iHOT-12 (chi 2 = 0.00; df = 1; p = 0.98), in the change in mHHS (chi 2 = 0.37; df = 1; p = 0.54), in the change in iHOT-12 (chi 2 = 1.05; df = 1; p = 0.30), in MCID of post-operative functional outcome scores (chi 2 = 0.43; df = 1; p = 0.51), in reoperation (chi 2 = 0.17; df = 1; p = 0.68), and in complications (chi 2 = 3.35; df = 1; p = 0.07). The absolute mean values for nearly all parameters favour PAO, which may indicate a potential advantage.ConclusionPAO and HAS yield comparable short- to mid-term outcomes in BDDH. Long-term studies are needed to determine whether HAS is a definitive treatment or delays structural correction. Future research should standardize BDDH definitions (LCEA 20-25 degrees) to enhance comparability and treatment consistency.Level of EvidenceA meta-analysis of retrospective and prospective primary studies.