Children under 5 years of age with Legg-Calvé-Perthes disease do not always have a good outcome, challenging the long-standing clinical impression of a universally benign prognosis in this age group.
This study attempted to analyze objectively the long-standing impression that children under 5 years of age, who have Legg–Calvé–Perthes disease, generally do well. Thirty patients, with 36 hips and onset of disease prior to their fifth birthday were reviewed at skeletal maturity. More than 50% of the hips were classified in Catterall group 3 or 4, and Herring group C. The end evaluation by the Stulberg classification showed 44.5% good, 22.2% fair and 33.3% poor results. By the Mose rating the results were respectively 27.8% good, 30.6% fair and 41.6% poor. A meta-analysis of the literature showed a very broad spectrum of results, leading to the conclusion, first, that comparison is difficult and, second, that young age is not a free ticket to a good result.
Fabry et al. (2003) studied this question.