A rare cause of arthropathy: An ochronotic patient with black joints

Abstract

INTRODUCTIONAlkaptonuria is an autosomal recessive disorder of metabolism. The pathogenesis of alkaptonuria includes chronic inflammation, degeneration, and eventually osteoarthritis. Ochronotic arthropathy is a rare condition found in patients with alkaptonuria.PRESENTATION OF CASEA 60-year-old female presented for evaluation after a 10-year history of low back pain, right hip pain, and bilateral knee pain. A cementless right total hip and a cemented left knee replacement were performed. Intraoperatively, the joint surfaces, neighboring ligaments, and tendons were black with pieces of black cartilage tissue. Histological sections of bone and soft tissue demonstrated classic findings of ochronosis, including multiple pigmented areas, reactive giant cells, and a thickened, inflamed synovium.DISCUSSIONThe management of ochronotic arthropathy in alkaptonuria patients is usually conservative, but replacement surgery is offered for severely affected hip and knee joints. A few reports of the surgical treatment of ochronotic arthropathy have been published. This report describes a case of ochronotic hip and knee arthritis treated with total hip and knee arthroplasties.CONCLUSIONJoint replacement has excellent outcomes in a patient with significant degenerative arthropathy due to ochronosis.

Ochronotic arthropathy—a rare clinical case

“…Alkaptonuria can be detected in children, as young as a few months of age by the presence of dark spots in the diapers or underwear, but patients are usually asymptomatic until arthropathy develops, after the fourth decade of life [ 1 , 6 , 7 ]. A plausible explanation for that is the renal tubular excretion of HGA: is very effective in the early years but becomes less so with age [ 7 ].…”

“…Currently, there is still no approved effective treatment for alkaptonuria; in OA the treatment is symptomatic and similarly to a normal arthropathy. However, surgical treatment may be necessary in cases of significant degenerative arthropathy [ 2 , 6 ].…”

Calcaneal Avulsion of an Ochronotic Achilles Tendon: A Case Report

“…In the present case, ochronosis was diagnosed shortly after the Achilles tendon surgery. Arthropathy is the main cause of symptoms of patients with alkaptonuria (11). Rupture of muscles, ligaments, and tendons are important features of alkaptonuria (4,18).…”

“…The diagnostic triad of ochronosis consists of degenerative arthritis, ochronotic pigmentation, and urine alkalinization. With advances in modern molecular identifying techniques, the early diagnosis of ochronosis can initiate early treatment before the destruction of tissues occurs (5,10,11). Dietary reduction of phenylalanine and tyrosine with administration of vitamin C of 1 g/day, vitamin E, nitisinone, N-acetyl cysteine, chondroitin, and glycosaminoglycan has been recommended (12)(13)(14)(15).…”

The potential of nitisinone for the treatment of alkaptonuria

“…Pain management is frequently administered, although the delivery of any analgesia can be impacted due to the ochronosis of tissues, particularly when considering the spine and shoulders [14][15][16][17][18]. Due to the lack of a disease modifying therapy, ultimately, multiple joint replacements are needed [19][20][21]. All of these only treat the symptoms, they do not deal with altering, removing or reducing the causative molecule, HGA, from the body.…”