Ochronotic arthropathy knee-arthroscopic diagnosis and treatment – A case report

Abstract

Ochronotic arthropathy is a rare hereditary disorder found in patients with Alkaptonuria due to a deficiency of Homogentisic acid oxidase. It is associated with the deposition of homogentisic acid derivatives in various connective tissues, causing characteristic pigmentation known as ochronosis. Due to its clinical resemblance to that of a degenerative disorder, the diagnosis of ochronotic arthropathy usually occurs intraoperatively. This case report is of a 56-year-old male who presented with complaints of pain and swelling in the right knee. Clinical examination and MRI findings were correlated to reveal a tear of the lateral meniscus. On arthroscopy, the blackish-brown pigmentation of the meniscus and the articular cartilage led to a diagnosis of ochronotic arthropathy. The pathology and biochemistry studies further support this. Arthroscopy plays an important tool in terms of the management of patients with ochronosis. The characteristic findings, in this case, report may help in establishing the diagnosis of ochronotic arthropathy without other systemic presentations. It can help in delaying inevitable progression and allow patients to be pain-free for longer periods. Arthroscopy delays the need for arthroplasty.