Legg-Calvé-Perthes Disease.

Legg-Calve-Perthes disease (LCPD) is the insidious onset of idiopathic avascular necrosis of the hip in the pediatric population. The disease encompasses a wide spectrum of pathology, from mild with no long-term sequelae to severe with permanent degenerative change of the hip joint. A pediatric patient with hip pathology may initially only present with knee or thigh pain, thus obligating the clinician to maintain awareness about the hip during examination. Common physical examination findings include deficits in hip abduction and internal rotation, along with Trendelenburg gait in late stages. Plain radiographs demonstrate changes in the anterolateral aspect of the femoral head, sometimes only seen on the frog lateral X-ray in early stages. Treatment options aim to restore range of motion and maintain adequate coverage of the femoral head. When appropriate, surgery is used to reorient the femoral head or pelvis to maintain coverage.