438 THE JOURNAL OF BONE AND JOINT SURGERY A CONTROLLED STUDY OF THE RESULTS OF FEMORAL OSTEOTOMY IN SEVERE PERTHES ’ DISEASE

hips and found that 50.7 per cent of treated patients developed congruous spherical femoral heads In contrast to 14. 1 per cent of those untreated. We have also considered certain other features relevant to the outcome. We suggest that the Indications should not be modified on the grounds of early age of onset. Relief from weight-bearIng does not appear to improve the results ofcontaInment. We have assessed the shortening which follows femoral osteotomy and conclude that this is only significant when there is growth disturbance at the capital epiphysis. These changes are at least as frequent In untreated patients. We previously reported the results of containment by femoral osteotomy in 48 children with Perthes’ disease who were unselected except in so far as those classified as Group 1 (Catterall 1971) and others with irreversible deformity of the femoral head at diagnosis were excluded (Lloyd-Roberts, Catterall and Salamon 1 976). These results were compared with the outcome in 75 untreated patients and in 95 for whom methods othe