6 years old boy presented with pain in the left hip and limping. Plain radiographs of the pelvis, AP and frog lateral views, were performed. Follow-up films were performed after 3 months. Follow-up films showed good healing of the left femoral epiphysis with a mild coxa magna deformity of the femoral neck.
|Pelvic X-ray - frog lateral view|
|follow up Pelvic Xray AP view|
The initial radiographs showed fragmentation of the left femoral epiphysis, which appears dense as compared with the right.
The aetiology of Perthes disease is idiopathic. It represents multiple vascular occlusive episodes that involve the femoral head, causing changes of avascular necrosis. It is a long ongoing process of vascular change and repair and is different from avascular necrosis secondary to trauma. It usually affects Caucasian boys (4-5 times more often than females), in the age group of 3-12 years, occurring bilaterally in 15% of cases and when bilateral is usually asymmetrical. When symmetric involvement is seen, hyporthyroidism and epiphyseal dysplasia should be excluded. The onset is earlier in females and the prognosis worse. There is increased incidence of associated congenital anomalies, congenital heart disease, pyloric stenosis and undescended testes.