Predictors of treatment duration in conservative management of developmental dysplasia of hip -a retrospective cohort study

Developmental dysplasia of the hip is a prevalent condition in newborns. However, predicting the duration of conservative treatment remains challenging. This study aimed to determine the duration of treatment more precisely by analyzing associated factors. We conducted a retrospective analysis and developed a linear regression model based on 503 patients treated at our institution over the last 10 years. A linear regression model (GLM) was used for predicting treatment duration (df residuals 371, df model 3, Pearson Chi2 78.9, Number of iterations 15). The baseline scenario thereby feature a child with an average age at the beginning of treatment (35th day of life), both sides pathologically affected, and a minimum alpha angle of 29 degrees. The GLM identified age at treatment onset, alpha angle, and bilaterality as significant predictors of treatment duration. A four-week delay in treatment initiation extended the duration by one week, while a 5-degree increase in the alpha angle reduced it by two weeks. Bilaterality added 19 days to treatment duration. However, sex and clinical hip instability did not significantly affect the treatment time. These findings enable the calculation of treatment duration based on identified factors, potentially improving the management and planning of conservative therapies for developmental dysplasia of the hip in newborns.