Outcome of late-onset Perthes' disease using four different treatment modalities.

PURPOSE: The outcome of Perthes' disease in children over 8 years tends to be poor. It is unclear whether any treatment modality alters the natural history. This study compares the results of four treatment modalities for this group of patients.
METHODS: A retrospective review was performed of prospectively collected data for 44 children (48 hips) with Catterall grade 2, 3 or 4 Perthes' disease with onset age 8 years or older followed to maturity. Patients were divided into four groups (a no-treatment group and three interventional groups). The interventional groups were demographically similar but the untreated patients were older and had poorer indices for most modalities.
RESULTS: Overall for all treatment modalities only 19% had a satisfactory Stulberg grade II outcome. Poorer outcomes (as assessed by center-edge angle and percentage femoral head coverage) were associated with increasing age, greater initial head deformity, and more head involvement. Initial head deformity did not remodel for any group and progressed despite plaster treatment or varus osteotomy but not after acetabular augmentation. Acetabular augmentation gave better outcomes for C/B ratio and center-edge angle.
CONCLUSIONS: Whatever the treatment, the outcome is poorer with increasing age. No treatment guarantees a good result for significant head involvement or initial deformity but acetabular augmentation improves C/B ratio and center-edge angle and prevents progressive femoral head deformity compared with no treatment, varus osteotomy, and plaster treatment.