Long-term follow-up of bilateral hip and knee arthroplasty secondary to ochronotic arthropathy

Alkaptonuria is a rare metabolic disorder caused by the deficiency of homogentisic acid oxidase enzyme, which is responsible for eliminating homogentisic acid from the body through the renal system. Excessive accumulation of homogentisic acid leads to ochronosis and ochronotic arthritis. Owing to the rarity of the disease, long-term functional outcomes of joint replacements of the hips and knees in ochronosis arthropathy are unconfirmed, and only a limited number of case reports are available on this. We present a case of a 45-year-old man with ochronosis and advanced osteoarthritis of both the hips and knees. He underwent bilateral hip and knee replacements as staged procedures. At a follow-up of more than 12 years, the man had full mobility with no loosening of implants.