Quantitative correlation between the initial and final femoral head deformity in Perthes' disease.

A review at maturity of 42 patients with Perthes' disease has allowed a correlation to be made between femoral head deformity during the initial phases of fragmentation and reparation, as quantified arthrographically, with the final shape and size of the femoral head measured on plain radiographs. Cases with loss of sphericity or coxa magna at maturity had significantly lower arthrographic indexes of deformity (p = 0.001 and p = 0.005 respectively), regardless of the age at presentation. All were treated uniformly by containment in recumbency and a daily exercise program.