Massive subperiosteal hemorrhage and femoral shaft osteonecrosis: a complication of tissue plasminogen activator therapy for purpura fulminans.

We present the case of a child who developed a massive subperiosteal hemorrhage and subsequent osteonecrosis of her right femur after treatment with tissue plasminogen activator for post-varicella streptococcal purpura fulminans. Radiographs showed posteromedial translation of the capital femoral epiphysis on the necrotic shaft, and the hip was immobilized. The femur slowly remodeled and has continued to grow. The child is independently ambulatory with a 2.1-cm leg length discrepancy, a varus deformity of the hip, and a valgus distal femur.