Total knee arthroplasty in alkaptonuric ochronosis: a case report

A 65-year-old male patient presented to our hospital with complaints of bilateral knee pain and functional limitation. Without a preoperative diagnosis of alkaptonuria, the patient was evaluated as grade IV osteoarthrosis according to the classical Kellgren Lawrence classification, and total knee arthroplasty was performed. The diagnosis of alkaptonuria was established in the postoperative period by examination of biopsy materials obtained during surgery. Alkaptonuria is generally diagnosed late due to its slow progression. In young patients presenting with large joint arthritis, ochronosis should be suspected as a possible diagnosis. In advanced ochronotic arthrosis, successful outcomes can be achieved with total joint replacement therapy.