股関節に発生したｏｓｔｅｏｉｄ ｏｓｔｅｏｍａの１例

Abstract

We report a case of osteoid osteoma of the femoral neck causing arthritis of the hip joint. The patient was an 18-year-old boy, who complained of limping and severe hip pain with limited range of motion. There was no abnormal radiological findings on his first visit to the doctor, immediately after the onset of pain. At our investigation one year after the onset of pain, radiograph showed sclerosis at the proximal femoral neck. MRI showed low intensity on T1WI and high intensity on T2WI in the femoal neck and high intensity on T2WI in the hip joint space. Bone scintiscan demonstrated an abnormal integration in the left hip joint. Tomography and computerized tomography revealed a nidus surrounded by a sclerotic lesion in the cortex of the left femoral neck. There was no infectious sign in laboratory data. Curettage and iliac bone graft were performed. The diagnosis of osteoid osteoma was confirmed by histology. Hip pain and limping disappeared after surgery, although, limited range of motion of the hip remained due to patient's lack of cooperation with rehabilitation. Osteoid osteoma causing hip arthritis was rare. Purulent arthritis, bone tumor and pigmented villonodular synovitis should be considered as a differential diagnosis.