Ochronosis: complicated tear of black meniscus

Black Colouration of the Knee Articular Cartilage after Spontaneously Recurrent Haemarthrosis

Mild discolouration of the articular cartilage is known to gradually occur during aging. However, pathological tissue pigmentation is occasionally induced under several specific conditions. In the present case, we performed total knee replacement in a patient with recurrent haemarthrosis. However, during the operation, we observed severe black colouration of the knee articular cartilage, due to the deposition of hemosiderin and lipofuscin. To our knowledge, this is the first report of severe cartilage pigmentation, due to hemosiderin and lipofuscin deposition in articular cartilage.

Ochronosis diagnosed after knee arthroscopy

INTRODUCTION

Ochronosis is a rare disorder which is defined as the deposition of metabolites of oxidation and polymerization of homogentisic acid, which have high affinity to collogen, in the connective tissues. It is a clinical condition characterized with ochronotic pigmentation of tissues, degenerative arthropathy of especially large joints and black discoloration of urine. In this paper we present a case of ochronosis diagnosed with biopsy and additional tests when a black discoloration of menisci and joint cartilage were detected during arthroscopic intervention for a degenerative meniscus tear.

PRESENTATION OF CASE

A forty two year-old male patient was operated for lateral meniscus tear of his right knee. The arthroscopic examination of right knee revealed black colored synovial hypertrophy and torn lateral meniscus. Partial meniscectomy was performed. The diagnosis of ochronosis was made after histopathologic examination.

DISCUSSION

Ochronotic pigment can accumulate in hyaline cartilage, tendon, skin, teeth, nail, sclera, tympanic membrane, heart valves, renal tubular cells, duramater, pancreas and walls of large arteries. In ochronosis the most frequently involved joints are knee and hip. In ochronotic arthropathy, articular cartilage become more sensitive to mechanical stresses. Our patient had meniscal tear, cartilage damage and black discoloration of synovial tissues and meniscus.

CONCLUSION

Arthroscopy may be helpful in diagnosis of ochronotic arthropathy.