Abstract
We describe a 21-year-old woman with chronic diffuse sclerosing osteomyelitis (CDSO) of the left femur. The patient presented with shortening of the left leg and intractable pain that was unrelieved with conventional analgesia. Radiological imaging and open bone biopsy confirmed the diagnosis of chronic diffuse sclerosing osteomyelitis. Treatment with risedronate was commenced and a dramatic response in the patient's symptoms and biochemical markers of bone turnover was observed. To our knowledge this is the first case of CDSO treated successfully with risedronate.