Legg–Calvé–Perthes disease

Abstract

Legg-Calve-Perthes disease is a form of idiopathic avascular necrosis of the femoral head, evolving to classical “coxa plana”, which will lead to secondary hip arthritis. Legg-Calve-Perthes syndrome occurs most commonly in boys than in girls by a ratio of 4 to 1, commonly in the age range of 4 to 8 years. Etiological factors are represented by vascular, traumatic, constitutional, endocrine,genetical, racial and socioeconomical factors. Three phases have been described: avascular necrosis, fragmentation and healed phase. Pathogenesis is represented by two concomitant processes, located in femoral ossific nucleus: resorbtion of necrotic bone and new bone genesis. Two forms are described: Potential form – no fracture occurs in subcondral level; Real form – after the fracture occurs. Clinical signs are represented by: pain – of mild nature, usually activityrelated; lameness walking, and limited hip motion. Radiological findings: three stages are described: Initial stage – characterized by a pathognomical sign “ nail scratch”; Second stage – The bony epiphysis begins to fragment, presenting areas of increased radiolucency and radiodensity; Third stage – normal bone density returns. Alterations in the shape of the femoral head occurs. Other exams – IRM, arthrography, scintigraphy Classifications: Catteral – associating “head at risk” signs, groupe 1 or 2 and no “head at risk sign” having good prognosis, 3 or 4 plus “head at risk” signs having poor prognosis; Salter and Thompson; Herring. Evolution of long term, leading to epiphyseal deformities in severe forms. Treatment: has been based on the containment principle, being represented by orthopedic treatment or surgical treatment