Spine fracture in ochronosis. Report of a case.

Ochronosis, the musculoskeletal manifestation of alkaptonuria, primarily involves the larger joints of the body, including the spine. Ankylosis of the thoracolumbar spine leads to progressive loss of flexibility. The case described is that of a 72-year-old man with ochronosis who suffered a hyperextension injury to his spine in a fall, resulting in a fracture through an ankylosed L2-L3 disk space. To the authors' knowledge, this is the first reported fracture of an ankylosed ochronotic spine.