Manabu Kubo

Three stress fractures at different sites in the same tibia-a case report

An 8-year-old boy who had no significant past medical history had right leg pain for 2 months while practicing judo and with walking. He had been participating in 2 hours of judo practice twice a week and running almost every day for 2 years. He denied direct trauma to the leg. The anterior midshaft of the right leg was tender, without swelling or redness. Plain radiographs revealed a lucent area in the anterior cortex of the midshaft of the tibia. A bone scan with technetium-99 demonstrated locally increased uptake at the site of symptoms. MRI showed an abnormal signal intensity at the same spot. These findings were compatible with a stress fracture of the midanterior cortex of the tibia. He was treated with cast immobilization, no weight bearing and ambulation on crutches. The cast was removed after 2 months and he had no pain on standing, although he complained of mild tenderness over the anterior midshaft of the tibia. The lucent area was visible on repeated radiographs, but less distinct than on the initial radiographs. We removed the cast and permitted ankle motion, no weight bearing and use of crutches, but prohibited physical activities for 3 more months. 3 months later, he still had some pain and radiographs demonstrated a lucent area in the anterior cortex with linear sclerotic changes in the upper third of the tibia. We continued prohibition of weight bearing on the right leg for 2 more months. Nevertheless, 2 months later he still had pain and radiographs revealed sclerotic changes in the lower third of the tibia, in addition to findings in the midshaft and upper third. At that time, he confessed that he had been running now and then in order to maintain his competitive level with fellow athletes. We strictly prohibited weight bearing and sports activities, except swimming. 4 months later, he said he had been following our recommendation and had no symptoms and radiographs were normal. 1 year later he had no symptoms. He had a normal physical constitution, normal skin condition, normal ocular and auditory systems, normal laxity and range of motion in his joints, with normal alignment of his legs. Laboratory findings including blood count, sedimentation rate, calcium, phosphate, alkaline phosphate, thyroid and parathyroid hormones were normal. There was no evidence of rickets at the end of the long bones and bone density was normal.