[Alkaptonuria detected during knee arthroplasty treatment]

Alkaptonuria (AKU) is a rare autosomal-recessive disease in the tyrosine metabolism pathway. AKU is due to a mutation of a gene coding for homogentisate dioxygenase, causing accumulation of homogentisic acid leading to a painful multisystemic disease. Damage to cartilage tissue is especially significant, and weight-bearing joints often require arthroplasty. Nitisinone, a drug already used in treatment of hereditary tyrosinaemia, could be approved for treatment of AKU. This case report describes the occurrence of AKU discovered in two brothers in connection with hip and knee arthroplasty.