The outcomes of treatment and prognostic determinants of patients with Perthes’ disease

Analysis based on scores of the sphericity of the femoral head showed that age at the onset of Perthes' disease, sex, and the form of treatment were significant prognostic factors of outcome. Multivariate analysis with dichotomization of the bone age (≤ 6 yrs or > 6 yrs) revealed significantly better sphericity scores after proximal femoral osteotomy or Salter osteotomy than after no treatment or ROM exercises in patients with a bone age of > six years at the time of onset. The regression tree analysis without prior dichotomization showed that the patients who were treated with a femoral osteotomy had significantly better outcomes than those who did not, in patients with a chronological age of > 7.6 years.