The changes of stress distribution in the femoral head with Perthes disease were observed under several condition. Finite element models were constructed referring to X-ray images and magnetic resonance images of the intact hip joint. The model was divided into five parts: cancellous bone, articular cartilage, necrotic bone, cortical bone, physeal cartilage. Material properties were alloted to these components by the past literature. The body weight and abductor muscle force were applied as loading. The model was altered to study the effect of age, the extent of necrosis, and lateralization of the fomoral head. Analysis were performed on a digital computer PC-9821(NEC) using the finite element program. There was no significant difference in stress distribution patterns regardless of age or extent of necrosis. However, compressive stresses were concentrated on the lateral portion of the epiphysis by lateralization of femoral head. The femoral head deformity in Perthes disease was more affected by the lateralization than by the age and the extent of necrosis.

We treated 11 patients with chronic osteomyelitis of the tibia or the foot by local excision and transfer of a peroneal myocutaneous island flap. This flap, pedicled proximally or distally on the peroneal artery and veins, provides viable muscle to fill the dead space in bone and skin to close the defect. Ten patients reviewed more than three years after operation were all free of drainage with no clinical or radiographic evidence of recurrence.