Abstract
Femoral head fracture following idiopathic osteonecrosis of the femoral head (ION) is rare. The patient was a 50-year-old woman with Systemic Lupus Erythematosus (SLE). In 2003, 10 months after the onset of SLE, she developed pain in the left hip without any history of injury and was subsequently unable to walk. Roentgenographs showed a left femoral head fracture, but osteonecrosis was not apparent. Femoral head replacement was performed. There was no significant collapse of the femoral head. Subcondral tissue showed complete necrosis. At the superior portion of the fracture, there were invading fibrous connective tissue, resorption of live bone, new woven bone formation, and appositional bone formation, as well as the ordinary fracture.
This case was diagnosed as fracture of the femoral head head following ION according to the microscopic examination findings. The femoral head fracture was the first sign of ION.
