Prognostic Value of Modified Lateral Pillar Classification in Legg-Calvé-Perthes Disease

BACKGROUND: To evaluate the usefulness of the modified lateral pillar classification as a prognostic factor in Legg-Calvé-Perthes disease (LCPD). METHODS: Thirty nine patients diagnosed with lateral pillar C in LCPD from May, 1977, to October, 2001 were reviewed, and their skeletal maturity was followed. The mean follow up duration was 12 years and 7 months (4 years, 6 months to 24 years, 9 months). Lateral pillar C classification was divided into C1 (50-75% collapse of the lateral pillar) and C2 (> 75%). All radiological and clinical prognostic factors were evaluated. The final results were evaluated according to the Stulberg classification. RESULTS: Twenty one and 18 of the affected hips were in groups C1 and C2, respectively. According to the Stulberg classification, the final results of group C1 were better than those of C2 (p = 0.002). Patients with more head-at-risk signs had significantly poorer outcomes. CONCLUSIONS: The modified lateral pillar classification has significant value for predicting the prognosis of LCPD.