[Fracture dislocation of the thoracic spine in ankylosing spondylitis. A case of spontaneous occurrence and an uncommon course].

One case of spontaneous Th 10 - Th 11 dislocation complicating ankylosing spondylitis is reported. The only functional consequences were cracks when the patient was moving. Surgical treatment was refused nevertheless after twelve year follow bone union had occurred without neurological impairment.