Ochronosis - The Role of Total Hip Replacement : A Case Report and Review of Literature

Alkaptonuria is a rare autosomal recessive, single-gene metabolic disease caused by the lack of the enzyme homogentisic acid oxidase and characterized by black pigmentation of cartilage and other connective tissues. 38 yr old male was admitted to the orthopedics ward with bilateral hip pain for the past 3 years and inability to walk for the past 1yr. He had also complained of brownish-black discolouration of urine when exposed to air. Physical examination revealed flexion 70, internal rotation and extension 0, external rotation 30 in both the hips. Radiological findings showed joint space narrowing, acetabular protrusion, sclerosis and subchondral cysts. Total hip replacement was performed on the right hip followed by the left. Histopathology showed brownish black staining of degenerated hyaline articular cartilage.Six months after the surgery, physical examination of the patient showed excellent results. There were no significant complaints. In our patient total hip replacement proved to be an excellent treatment for his ochronotic hips. Total joint arthroplasty is an effective method in the treatment of late stage osteoarthritis due to ochronosis and the technique of in cases of ochronoticarthropathy is similar to osteoarthritis due to any other etiology.