Total Hip Arthroplasty for Ochronosis: A Report of Three Cases.

Introduction: Ochronosis is a rare metabolic disorder, characterized by accumulation of homogentisic acid in the connective tissues due to the lack of the enzyme homogentisic acid oxidase. The musculoskeletal manifestation of alkaptonuria is black pigmentation of cartilage of the knee and the hip leading to arthropathy.

Case Report: In this article, we report three patients with involvement of hip, knee, and spine, but with more severe involvement of the hips.