Ochronotic spondyloarthropathy: spinal involvement resembling ankylosing spondylitis.

Ochronotic spondyloarthropathy is a rare metabolic disease with the musculoskeletal manifestations of alkaptonuria. Ochronotic arthropathy patients may have spinal abnormalities similar to ankylosing spondylitis (AS). The proof of sacroiliac involvement or bamboo spine appearance is not sufficient either for diagnosis of ankylosing spondilitis or exclusion of ochronosis. In this report, the case of a 54-year-old woman having ochronosis, with clinically more recognizable axial arthropathy resembling AS, is presented, and the history, clinical presentation, diagnostic techniques, and distinctive diagnosis are reviewed.