[Perthes disease with onset after nine years of age].

The aim of this study is to evaluate and compare selected clinical and radiological hip joint parameters in Perthes disease with onset before and after 9 years of age. Analysis was based on 261 patients with unilateral Perthes disease. Patient with bilateral changes ware excluded because of earlier onset before 9 years old. The average age of patients at the time of initial symptoms was 7,1 years ( 2,5 - 13 years). The follow-up ranged from 16 to 50 years (average 20, 2 years). The clinical analysis was based on evaluation of age, gender and range of passive abduction. The radiological assessment was based on Catterall and Herring classifications, lateral subluxation, premature physeal closure by Bowen classification, limb length discrepancy, shape of the lateral acetabulum rim, ATD distance and index, center-edge angle, the Mose Classification, epiphyseal index and quotient. Assessments of final results were based on The Mose Classification and the Stulberg Classification. We affirmed that, in children with the onset of disease after 9 years of age, asymmetrical premature physeal closure, major lateralization, grater contour of the head deviation (Mose) and trochanteric overgrowth were more frequent occurred than in children with Perthes disease before 9 years of age. Patients who were over the age of 9 years at the time of onset and have a hip in Catterall 3 group and 4 group together with the lateral pillar B group or C group get a poor outcome. There were not any differences in the outcomes in Catterall 1 and 2 group together with Hering A group depending on age at the time of onset. Both age at the time of onset after 9 and quantity of femoral head necrosis have the most significant impact on the outcome, leading to poor final results. In accordance with our observation we do advise caution in older children's treatment with femoral varus osteotomy.