Alkaptonuria is a rare autosomal recessive metabolic disorder. It is characterized by the accumulation of homogentisic acid in the body due to a lack of enzymes that degrade it. Over time, it results in joint degeneration and eventually leads to ochronosis. Ochronosis refers to bluish-black discoloration of connective and other tissues within the body. In this study, we present 5 distinct cases diagnosed with alkaptonuria. They have undergone 8 total joint replacement surgeries (4 hips and 4 knees) within 8 years (2010-2018).
