Legg-calvé-perthes disease: Diagnosis, imaging, and classifications

Legg-Calve-Perthes disease (LCPD) is a self-limited childhood hip disorder of unknown etiology that can produce permanent deformity of the femoral head. Legg of the United States, Calve of France, and Perthes of Germany independently described the disease in 1910 [1]. The onset of LCPD occurs between 2 and 15 years of age with a peak between 4 and 9 years. Sundt in 1920 reported that boys were four times more likely to have the disease than girls and that 10 % of patients developed bilateral disease [2]. Molloy in 1966 [3] and Catterall in 1981 [4] reported similar findings with bilateral disease occurring in 10–15 % of patients and male-to-female ratio of 4–5:1. The diagnosis of LCPD requires plain radiography and careful history taking as its symptoms and physical findings are nonspecific and it is a diagnosis of exclusion. Other pediatric conditions that produce femoral head osteonecrosis or LCPD-like changes on radiography must be ruled out through history, physical examination, and radiographic assessment.