Alkaptonuria in an Elderly Presenting with Asynchronous Rupture of both Quadriceps Tendons and Chronic Kidney Failure: Case Report and Literature Review.

INTRODUCTION: Alkaptonuria (AKU) is a rare autosomal-recessive multisystemic disease. It is caused by a mutant homogentisate dioxygenase coding gene, leading to the accumulation of homogentisic acid (HGA), hence systemic manifestations. Renal manifestations and tendon rupture are rarely reported.

CASE REPORT: We report a 60-year-old male with chronic kidney disease for over a decade who was initially misdiagnosed with ankylosing spondylitis and rheumatoid arthritis. Later on, the patient presented to our institute with a non-synchronized (8 years) acute quadriceps tendon rupture.

CONCLUSION: Physicians should be aware of the importance of prophylactic measures in the management of AKU, which is mainly medical management, to reduce the accumulation of HGA in the body. We further emphasize this point to reduce the incidence of subsequent tendon ruptures, as it significantly affects the quality of life.