Slipped capital femoral epiphysis.

Slipped capital femoral epiphysis occurs during the adolescent growth spurt and is most frequent in obese children. Up to 40 percent of cases are bilateral. Recent classification methods emphasize epiphyseal stability rather than symptom duration. Most cases of slipped capital femoral epiphyses are stable and have a good prognosis if diagnosed early. Unstable slipped capital femoral epiphysis has a much poorer prognosis because of the high risk of avascular necrosis. Early radiographic clues are the metaphyseal blanch sign and Klein's line. Once diagnosed, treatment should begin immediately. The most widely accepted treatment for a stable slipped capital femoral epiphysis is in situ fixation with a single central screw. The treatment for an unstable slipped capital femoral epiphysis is much more controversial. Corrective osteotomy is usually reserved for treatment of severe deformities after the patient has stopped growing.