Alkaptonuric Ochronosis: A case-based review.

Alkaptonuria (AKU) is an extremely rare autosomal recessive metabolic disorder caused by deficiency of homogentisic acid oxidase and resulting in accumulation of homogentisic acid in collagenous structures. It is characterized by a triad of homogentisic aciduria, bluish-black discoloration of connective tissues (ochronosis) and arthropathy of large weight bearing joints. We report on a middle-aged female patient with bilateral severe ochronotic arthritis of both hips and shoulder joints requiring total joint replacements as staged procedures which were done without complications offering a complete pain relief and a satisfactory clinical and functional outcome. Ochronosis can cause severe arthropathy of peripheral joints. Multiple joint affection is common. Total joint replacement can yield persistent pain relief with complete functional recovery in patients with severe ochronotic arthropathy.