Ochronotic arthropathy

Abstract
Ochronotic arthropathy is the musculoskeletal manifestation of alkaptonuria, an uncommon inherited metabolic disorder associated with various clinical and radiologic abnormalities due to the deposition of homogentisic acid. We report on a 35-year-old man with ochronotic arthropathy who presented with the main characteristic radiological findings. The differential diagnosis of this rare condition is discussed with a review of the literature.