Determination of the Catterall classification in Legg-Calvé-Perthes disease.

Fifty hips in forty-four children with Legg-Calvé-Perthes disease, treated at the Shriners Hospital for Crippled Children, San Francisco, were evaluated with a simplified method of Catterall's classification. Our data indicate that the Catterall rating changed in 40 per cent of the hips when they were classified before they had reached the fragmentation stage of Waldenström compared with only 6 per cent when they were classified after fragmentation had occurred.