To The Editor:The paper "Legg-Calvé-Perthes Disease. Part II: Prospective
Multicenter Study of the Effect of Treatment on Outcome"
(2004;86:2121-34), by Herring et al., is a landmark in pediatric orthopaedics.
Dr. Herring et al. and the Legg-Perthes Study Group are to be congratulated on
accumulating so many data in a prospective long-term study.The authors have performed an expansive analysis. Sample-size constraints
led the authors to combine groups and to conclude that operative treatment was
better than nonoperative treatment. However, if we compare bracing and
surgical treatment (containment) with range-of-motion exercises and no
treatment (noncontainment), the difference is highly significant in favor of
containment (chi-square analysis; p < 0.01). When operative treatment is
compared with bracing, no significant difference is observed, although the
sample sizes are roughly equivalent (129 in the bracing group and 119 in the
operative treatment group). The authors appear to have been selective in their
comparisons. On the basis of logistic regression and Wald chi-square tests,
the most important factors were classification and age, not treatment.