Aim: The neonatal screening procedure in South Australia has shown that the late diagnosis of developmental dysplasia of the hip (DDH) is rare with well conducted clinical screening. We studied the cases of late diagnosis of DDH to determine the epidemiological features and the out come of management with special reference to development of the femoral head and acetabulum.

Methods: Patients’ case records and radiographs with a delayed diagnosis of DDH, identified by the South Australian Birth Defects Register between 1988 and 1993, were reviewed. Epidemiological features, acetabular angles, size of femoral head, spherical index, CE angle and migration percentage were examined. The Severin’s grouping and Makey’s criteria were used to assess radiological and clinical outcomes. Late DDH was defined as DDH diagnosed after three months of age.

Results: The acetabular angles and percentage coverage improved rapidly -faster in younger children. The CE angle also improved rapidly. When treatment was started late (after one year) the improvement was slower and final out come was unpredictable. The femoral head continued to grow irrespective of age at reduction and became normal in most cases. In some patients Salter osteotomies stabilised the hips after open reductions and gave excellent results. The epidemiological features were compared with that of DDH diagnosed early in postnatal life.

Conclusions: Clinical screening and early detection is important in the outcome of DDH. Early treatment may give better results.