Alkaptonuria is an autozomal recessive metabolic disease that goes with the deficiency of homo-gentisic acid oxidase. Collection of the metabolits of HGA in connective tissues results ochronosis. In this article, we discuss a patient who came to us with backache and knee pain. After physical and radiological examination we planned a cementless total knee arthroplasty. Intraoperatively, we recognized the brown-black colour in the soft tissues. The pathological analysis matched with ochronosis.
Keywords: Ochronosis, Alkaptonuria, Ochronotic arthropathy, Homogentisic acid oxidase
