Age of initiation of treatment for hip dysplasia with Pavlik harness and residual dysplasia

The successful treatment of hip dysplasia consists of achieving a concentric reduction and avoiding residual dysplasia. One of the essential factors is early diagnosis and treatment. Objective: Evaluate the relationship between the age at initiation of hip dysplasia treatment and the presence of residual dysplasia at one year of age. Patients and Method: Prognostic retrospective study. Patients with hip dysplasia treated with Pavlik harness in a tertiary healthcare center were selected. Residual dysplasia was defined as an acetabular index greater than 28 degrees at one year of age. An association of residual dysplasia with the age at treatment initiation, bilaterality, and acetabular index more than 36 degrees was determined. The T-Student, Chi-Square, and Youden index tests were used. A p-value < 0.05 was considered significant. The STATA v.16 software was used. Results: 153 patients (262 hips) were included, 84.3% (129) were females, and 71.2% (109) presented bilateral dysplasia. Fifty-nine hips (22.52%) presented residual dysplasia, finding a significant association with the age at treatment initiation (p = 0.03), bilateral dysplasia (p < 0.01), and acetabular index greater than 36 degrees (p = 0.01). Starting treatment after 4.5 months increases the risk of residual dysplasia by 2.5 times (95% CI 1.25-5.03). Conclusion: An increase in residual dysplasia was observed at the start of treatment after 4.5 months. It is relevant to consider this result in local clinical guidelines to achieve a successful diagnosis and treatment.