Ochronosis as Etiology of Requiring Total Knee Arthroplasty-A Case Series.

Alkaptonuria is a rare hereditary metabolic disorder that leads to the accumulation of homogentisic acid accumulation and weakens the collagen, creating fissuring and articular cartilage degeneration. Therefore, we are reporting a multicenter case series of three patients (four arthroplasties) who presented with signs and symptoms of ochronotic arthropathy-and eventually underwent total knee arthroplasty (TKA)-and provide a review of the current literature on total joint arthroplasty in ochronotic osteoarthritis. Each patient achieved excellent Knee Society Scores (KSS) after at least a five-year follow-up-regardless of receiving cemented or cementless prostheses-and suffered no complications. There have been a number of case reports published on patients who had TKA and were found to have a diagnosis of ochronosis. We believe that surgery for symptomatic patients who are surgical candidates for TKA should not be delayed for concerns of complications. However, future studies should compare outcomes to those who undergo TKA without ochronotic arthropathy.