Total Joint Arthroplasty in Ochronotic Arthritis of Lower Extremities.

Background: Ochronotic arthropathy is an inherited metabolic disease manifestation of alkaptonuria (AKU), commonly involving the spine, knees and hips. End-stage ochronotic arthritis (OcA) requiring total joint arthroplasty (TJA) is uncommon, with only few case series being described in English literature.

Materials: The objective of current study is to share our surgical experience of treating four patients with end-stage arthritis, who underwent eight TJAs of the lower extremity (5 hips and 3 knees) in whom an intraoperative diagnosis of ochronosis was suspected after surgical exposure of the operated joint. We describe the intraoperative challenges faced during surgical treatment, diagnostic tests and mid-term follow-up results.

Results: Four AKU patients (3 females) with end-stage OcA of the hips and/or knees, underwent eight total joint replacement surgeries, under neuraxial anesthesia in the majority. All patients were either in their late fifties or sixties at the time of their index TJA. We encountered one case each of peri-prosthetic fracture, medullary canal perforation and early prosthetic infection, all of which were successfully treated. The mean follow-up was 5.2 years (1-10 years) and all patients had satisfactory clinical outcomes at the last follow-up.

Conclusions: The surprise intraoperative diagnosis of OcA, along with associated juxta-articular sclerosis or osteopenia can lead to intra-operative complications. These complications when addressed appropriately did not adversely affect the clinical outcomes of TJA for end-stage hip and knee arthritis, at a medium-term follow-up.