THE EPIDEMIOLOGY OF DEVELOPMENTAL DYSPLASIA OF THE HIP IN MALES

Developmental Dysplasia of the Hip (DDH) is one of the most common orthopedic hip diseases of the pediatric population. There is a predominance in females and patients with known risk factors. Objective: To evaluate the characteristics of DDH in a reference center and compare them with the literature. Methods: This is a cross-sectional observational study based on the review of medical records and radiographs from which epidemiological data such as laterality, age at diagnosis, acetabular index, radio- graphic classification and others were collected. Results: A total of 297 medical records were found between May 1974 and June 2009. Of those, 147 patients (216 affected hips) were eligible for the survey. Most of the patients came from the state of São Paulo (91.1%), were born in autumn/winter (66.7%), reported as Caucasians (76.9%), with bilateral involvement (46.9%) and mean age at diagnosis of 22.8 months. Conclusion: The most frequent type of DDH was high dislocation (28.7%), and the acetabular index progressively increased with the age. The International Hip Dysplasia Institute classification was found to be more re- producible than Tönnis classification. Delayed diagnosis was associated with the absence of risk factors and with bilaterality. Level of Evidence III, Retrospective comparative study.