Abstract
We encountered a case of degenerative osteoarthritis due to alcaptonuria, an inherited disorder of tyrosine metabolism. A 58-year-old woman was admitted to our hospital due to hip pain. A hip simple X-ray picture revealed terminal stage of degenerative hip osteoarthritis. A simple lumbar X-ray showed calcification of multiple lumbar discs, which was suggestive of alcaptonuria. During total hip osteoarthroplasty surgery, we noted black coloration (ochronosis) of the femoral neck, a characteristic sign of alcaptonuria. Alcaptonuria was eventually diagnosed by black coloration of the urine and detection of homogentisate in the urine using gas chromatography-mass spectrometry method. Although gait disturbance and hip pain disappeared after total hip arthroplasty surgery, careful follow-up is necessary for early detection of various complications of alkaptonuria in other organs.
