We present here a follow-up study concerning Legg-Calvé-Perthes. This study about 71 hips shows that the Catterall grouping, age and "at risk signs" are still to be considered as very important prognostical factors. A definitive and indispensable scheme of treatment has not yet been advanced, especially because the right etiology still remains an obscure point. The cited "classical" prognostic factors however remain all-important.