Sacral stress fracture in a runner.

A female 10,000 metre runner, aged 28, presented with a 10 day history of pain of insidious onset in the right buttock. She had, 2 weeks before presenting, competed in a track race for selection to an international representative team, which she achieved. Five days after the race she had a 400 metre interval training session, following which she was conscious of the pain in the right buttock. She continued with her road training, but was aware that her stride was shortened due to the pain which worsened over the subsequent week. She was due to compete internationally some 6 weeks later. On examination there was a small degree of pelvic tilt, the left side being lower than the right. There was slight compensatory lumbar scoliosis, concave to the right. Clinically, the right leg appeared longer than the left by not more than one half of an inch (1.25 cm). Movement of the lumbar spine was full and equal in all directions. There was no localized spinal tenderness. Both sacroiliac joints were tender. There was acute and very localized tenderness in the upper, outer quadrant of the right buttock. No abnormality was found in the hips, other than passive extension of the right hip was slightly limited by comparison with the left. The pain could not be reproduced by passive or resisted movements of the hip. A plain X-ray of the lumbar spine and pelvis showed no significant abnormality and there was no evidence of erosive change at either sacroiliac joint. A three phase isotope bone scan, 18 days after the reported onset of the pain, showed some early, slight uptake at the lower end of the right sacroiliac joint on the sacral side. The appearances were reported as compatible with a stress related lesion involving the lower medial component of the right sacroiliac joint (Figure 1). In the view of a consultant rheumatologist, to whom the patient was referred, the lesion was sacroiliac strain, for which an injection of triamcino-lone and local anaesthetic was given. The athlete was recommended not to run and, instead, continued to train in water, using a wet vest. One week after the injection, 4 weeks after the onset of pain, the athlete travelled to a training camp before R L L R Anterior Posterior Figure 1. Isotope bone scan showing slight uptake at the lower end of the right sacroiliac joint on the sacral …