Does the Cartilaginous Index Affect Acetabular Development in Developmental Dysplasia of the Hip? A Radiographic Study on Patients with Long-term Follow-up

Objective: Developmental dysplasia of the hip is one of the most common infantile diseases. Estimating the roles of factors affecting the development of dysplastic hip is essential in determining the treatment outcomes. In this study, we investigated if the cartilaginous acetabular index (CAI), osseous acetabular index, or their difference (delta angle) affect acetabular development in the long- term follow-up. Method: Thirty-five hips of 30 patients are included in the study. The mean age of the patients was 15.71+-6.37 (3-31) months. All patients were treated using a medial approach. The mean follow-up was 149.91+-51.43 (60-262) months. Five hips were excluded due to the development of avascular necrosis. Results: Any statistically significant difference was not found in the evaluation of the correlation between CAI, osseous acetabular index, or delta angle measurements in terms of acetabular development. The acetabular growth in the first year following the reduction was statistically significant (p0.05). Conclusion: CAI, osseous acetabular index, and delta angles do not directly affect acetabular development rate. However, most of the acetabular development occurs during the first year after concentric reduction in children younger than 24 months.