ALKAPTONURIA DIAGNOSED IN A 72 YEAR OLD FEMALE AFTER TOTAL KNEE REPLACEMENT

Abstract

Alkaptonuria is a rare autosomal recessive disorder of metabolism caused by deficiency of homogentisic acid oxidase and resulting in accumulation of homogentisic acid in collagenous structures. It is characterized by homogentisic aciduria, bluish-black discoloration of connective tissues (ochronosis) and arthropathy of large joints. Less common manifestations include cardiovascular abnormalities, renal, urethral and prostate calculi. Bone fractures are unusual in ochronosis. In this report, we describe a woman, 72 years of age, with a history of severe arthropathy requiring total joint replacement in both of her hips and left Knee. During the Left Total Knee Replacement, an intra operative observation of a bluish-black discoloration of the knee joint and the surrounding soft tissue raised the diagnosis of Alkaptonuria. We review the etiology, pathogenesis, clinical presentation, diagnosis and treatment of alkaptonuric ochronosis. Early detection is important for prevention and treatment of multiple systems.