Abstract
BACKGROUND: Developmental Dysplasia of the Hip (DDH) is a prevalent pediatric condition affecting 1-3% of newborns worldwide. Early treatment is crucial to prevent long-term complications such as residual dysplasia, avascular necrosis (AVN), and osteoarthritis. Despite the widespread use of the Pavlik harness, the optimal timing of hip orthosis initiation remains a topic of debate. This systematic review and meta-analysis evaluate the impact of age and timing of hip orthosis application on treatment outcomes in infants with DDH. METHODS: This systematic review was registered on PROSPERO (Registration No. CRD42025638433). A comprehensive literature search was conducted in PubMed, Scopus, and Cochrane Library for studies published between 2000 and 2024. Twenty-two studies meeting inclusion criteria were analyzed, focusing on success rates, healing times, and complications such as AVN and residual dysplasia. Data were pooled for meta-analysis, and statistical analyses were performed using a random-effects model to assess the impact of treatment timing. RESULTS: Infants treated before 3 months of age achieved a pooled success rate of 88.79 % (SE: 0.57 %), with lower complication rates, including AVN (0.89 %, SE: 0.18 %) and residual dysplasia (1.80 %, SE: 0.25 %). In contrast, treatment initiation between 3 and 6 months had a slightly lower success rate of 87.78 % (SE: 0.34 %), but with higher AVN (9.66 %, SE: 0.30 %) and residual dysplasia (20.27 %, SE: 0.40 %) rates. The Pavlik harness and Tübingen hip flexion splint were most effective in early-treated cases, whereas later treatment initiation or severe presentations resulted in less favorable outcomes. CONCLUSION: Early treatment initiation, particularly before 3 months of age, significantly improves treatment success and reduces long-term complications. These findings emphasize the necessity of early screening and timely intervention to optimize outcomes. Future research should focus on refining treatment protocols for delayed presentations and improving management strategies for severe dysplasia. LEVEL OF EVIDENCE: Level IV.