Arthroscopic diagnosis and management of ochronotic arthropathy of the knee

The Black Knee - A Case Report

Introduction

Ochronotic arthropathy in patients with alkaptonuria is a rare hereditary disorder. The altered metabolism causes the homogentesic acid derivatives to deposit in various connective tissues causing characteristic pigmentation. Due to the close clinical resemblance to that of a degenerative disorder, diagnosis of ochronotic arthropathy usually occurs intraoperatively. We report arthroscopic findings of a 50-year-old female with ochronotic arthropathy.

Case Report

A 50-year-old woman came with complaints of pain and swelling in the left knee. Clinical examination and MRI findings were correlated to reveal a tear of lateral meniscus. On arthroscopic examination, the blackish pigmentation of the meniscus and the articular cartilage led to the diagnosis of ochronotic arthropathy.

Conclusion

Arthroscopy plays an important role in diagnosis and treatment of patients with ochronotic arthropathy. The characteristic arthroscopic finding may aid diagnosis even in patients who do not have other systemic manifestations. Timely arthroscopic intervention can help delay the disease progression.

Ochronotic arthritis and ochronotic Achilles tendon rupture in alkaptonuria: A 6 years follow-up case report in China

INTRODUCTION

Alkaptonuria (AKU) is a rare disease caused by deficiency of homogentisate 1,2-dioxygenase which results in deposition of homogentisic acid (HGA). Ochronotic arthritis, the deposition of excess oxidized HGA in the connective tissues, causes pigmentation and degeneration of the joint tissues ultimately resulting in chronic inflammation and osteoarthritis. The ochronotic arthritis has similar clinical features with osteoarthritis. There is currently no specific treatment for AKU and management is usually symptomatic. In severe cases, total joint arthroplasty is the major treatment approaches. It is rarely reported in China.

PATIENT CONCERNS

Here we reported a case of a patient with bilateral knee pain for more than 1 year. He complained of a 20-year history of chronic, nonspecific low back pain and stiffness. His urine was black since he was a child. Six years after the knee surgery, his Achilles tendon ruptured.

DIAGNOSIS

Specific radiographic and magnetic resonance imaging manifestations were observed. Darkly pigmented full-thickness cartilage and subchondral bone were found during the operation. Histological investigation also manifested dark stains in meniscus and synovial tissues. Black-denatured tendon tissue was also found during the operation. The patient was diagnosed as AKU.

INTERVENTIONS

Total knee arthroplasty and Achilles tendon repair were operated separately after the disease was diagnosed.

OUTCOMES

The patient recovered very well after the second surgery. He returned to full activities, described no knee pain, and presented to the clinic walking without any aid. Physical examination revealed 0 to 20 of plantar flexion and 0 to 15 of dorsiflexion of the ankle.

CONCLUSIONS

Ochronosis is a very rare disease in Asia. This paper supplies new information for study of this disease. The mechanism is still unknown right now. Further studies will be necessary.

Knee Arthroscopy: A Diagnostic and Therapeutic Tool for Management of Ochronotic Arthropathy

The surgical treatment of ochronotic arthropathy remains unclear. Although there is no absolute cure for ochronotic arthropathy, current management typically begins with conservative treatment. Total joint replacement may eventually be necessary for joints that become severely degenerative. Ochronotic arthropathy is present in patients with alkaptonuric ochronosis, which is characterized by dark pigmentation of connective tissue and black discoloration of urine owing to a deficiency of homogentisic acid oxidase. As a result, soft tissues become brittle and subsequently more susceptible to mechanical stress, resulting in articular cartilage degeneration. The diagnosis of ochronotic arthropathy of the knee often occurs intraoperatively after discovery of darkened synovium and black deposits during arthroscopy. The purpose of this article is to describe arthroscopic debridement as an effective treatment option and diagnostic tool for ochronotic arthropathy of the knee after failure of conservative measures.

Ochronotic black meniscus during knee arthroscopy

Ochronotic arthropathy is a rare condition found in patients with alkaptonuria, which is a hereditary metabolic disease associated with deposition the of homogentisic acid derivatives in various connective tissues of the body. We present the case of a 30-year-old woman in whom arthroscopic examination of the left knee prior to meniscectomy for bucket handle tear of medial meniscus revealed brown-black discoloration of the articular cartilage and menisci leading to the diagnosis of alkaptonuria by further laboratory evaluation. After medical and surgical treatment, patient's complaints were alleviated and no further complaints were registered, during the next follow-up.

Ochronosis: complicated tear of black meniscus

We describe a case of a previously healthy 35-year-old man who presents with meniscal symptoms, and present the arthroscopic findings of a complicated tear of black lateral meniscus. Investigations revealed that he had underlying alkaptonuria, which was previously undiagnosed without any other findings. After the surgical treatment, the patient's complaints were alleviated and almost no complaints were registered, during the next follow-up.

Ochronosis, arthroscopy of a black knee: a case report and review of the literature

Ochronotic arthropathy is a rare condition found in patients with alkaptonuria. Due to the accumulation of homogentisic acid, cartilages get a dark discoloration and become brittle and more vulnerable to mechanical stress (Centinus et al. Rheumatol Int 3:127-131, 2004; Hamdi et al. Int Orthop 23:122-125, 1999; Phornphutkul, N Engl J Med 347:2111-2121, 2002; Thacker, Arthroscopy 19:14-17, 2003). This case report is about a patient first diagnosed for ochronosis by arthroscopy of the knee. Her brother was having similar complaints during follow-up. Both patients were prescribed to take glucosamine and chondroitine. Although no report is found in the literature, regarding the success of this therapy in patients with ochronosis, both patients reported a positive effect on articular pain and daily activities.

Arthroscopic treatment of shoulder ochronotic arthropathy: a case report and review of literature

Alcaptonuria is an inherited hereditary metabolic disorder, which is associated with various systemic abnormalities and related to the accumulation of homogentisic acid and a derived melanine-like pigment in the connective tissues; the latter is termed ochronosis. We present the arthroscopic findings in the shoulder of a 58-year-old female with ochronotic arthropathy and discuss the role of arthroscopy in the diagnosis and management of this rare metabolic disorder.

Ochronotic arthropathy: arthroscopic findings in the shoulder and the knee

Ochronotic arthropathy is a disorder resulting from the deposition of homogentisic acid derivatives in the articular cartilage and the menisci. Large joints of the appendicular skeleton are preferentially affected. The clinical picture resembles that of degenerative joint disease. We present the arthroscopic findings in the shoulder and the knee in a 40-year-old man with ochronotic arthropathy and discuss the role of arthroscopy in the diagnosis and management of this rare metabolic disorder.