TREATMENT OF THE UNSTABLE (ACUTE) SLIPPED CAPITAL FEMORAL EPIPHYSIS

Slipped capital femoral epiphysis, the most common hip disorder in ado lescence, traditionally has been classified according to symptom durat ion. An acute slip is 1 in which there are symptoms for <3 weeks; for a chronic slip, there are symptoms for >3 weeks. An acute-on-chronic s lip is characterized by a combination of both with a recent exacerbati on of symptoms. This classification system is misleading because it do es not consider stability. A stable slipped capital femoral epiphysis has a good prognosis, but an unstable slip has a guarded prognosis. Th e priorities in treating an unstable (acute) slip are (1) to avoid ava scular necrosis, (2) to avoid chondrolysis, (3) to prevent further sli p, and (4) to correct deformity. The last priority, correcting the def ormity, is associated with a high incidence of complications including avascular necrosis and chondrolysis, so manipulative reduction under anesthesia or an acute corrective osteotomy is not recommended. To add ress these priorities in treatment, the authors recommend preoperative bed rest to decrease the synovitis and intraarticular effusion, Opera tive stabilization is done in an elective fashion once the synovitis h as subsided. The technique includes careful patient positioning on the fracture table, which may cause an incidental reduction, but no attem pt is made to do a manipulative reduction. The technique is dependent on radiographic control. The femoral head and neck must be well visual ized on the anteroposterior and lateral intensifier images before the operation is started. The slipped capital femoral epiphysis is stabili zed with a single central screw, and nonweightbearing ambulation with crutches is recommended until a satisfactory painless range of motion has returned.