Avascular necrosis of the femoral head in children with chronic renal disease

PURPOSE: To determine the incidence of avascular necrosis (AVN) of the femoral head in children with chronic renal failure. MATERIALS AND METHODS: Pelvic radiographs in 205 children (age range, 6 months to 16 years; mean age, 6 years +/- 3.5 [SDI) with chronic renal failure were reviewed. Serial radiographs were obtained every 6 months for 1-7 years (mean, 3 years +/- 2) to assess the presence of AVN of the femoral head; six children had metabolic renal disease, 21 had acquired renal disease, and 178 had structural renal lesions. RESULTS: Radiographic findings of AVN were seen in 14 of 205 patients (approximately one in every 15). The frequency of AVN was similar in boys and girls; AVN was observed in 11 (6.9%) of 159 boys and in three (6.5%) of 46 girls and was not related to the duration of renal disease, type of renal disease, or growth hormone therapy. Affected children were frequently asymptomatic, and, when present, the clinical complaints were mild. In two instances, AVN developed while the patients were receiving corticosteroids before entering this study. CONCLUSION: The results of this study indicate that AVN of the femoral head is a frequent complication in children with chronic renal failure, occurring in approximately 7% of this population. Unlike Legg-Calve-Perthes disease, AVN in children with chronic renal failure is frequently asymptomatic and has no sex predilection.