Twenty-four hours after a car accident, a 47-year-old man with chronic low back pain-which had been diagnosed years earlier as "arthritis" of the spine-presented with back and chest pain and requested an opioid analgesic. The patient had a history of alcoholism and illicit drug use. Tenderness of the thoracic area was noted. The ECG was normal. Plain films of the thoracic spine revealed ossification of the anterior longitudinal ligament and ankylosis of the facet joints, which featured a "bamboo spine" appearance. These findings led Drs John Whyte, now of Washington, DC, and Anthony Filly of Palo Alto, Calif, to suspect ankylosing spondylitis. There were no signs of systemic disease. CT scans showed a transverse fracture through the fused disk space and the posterior elements at the T9-T10 vertebral body level. A brace was tried; however, the patient was noncompliant. He complained of new-onset electric sensations down his back that occurred with motion. The patient was admitted to the hospital; complete bed rest and dexamethasone( were tried for several days without success. A T9 thoracic decompressive laminectomy with T8-T10 pedicle screw fixation and posterolateral arthrodesis was performed. The postoperative course was complicated by pneumonia, which responded to treatment. The patient's recovery from surgery was otherwise uneventful; he is doing well and has no neurologic deficits.