Abstract
INTRODUCTION: Alkaptunurea is a rare metabolic disorder with autosomal recessive genetic pattern in transmission, it is characterized by accumulation of hemogenistic acid in the tissues due to deficiency of homogentisate 1,2 dioxygenase activity. Characteristically, affected patient will have dark urine and blackish discoloration of connective tissue, especially cartilage and bone and hence it is known as black bone disease. PRESENTATION OF THE CASE: The reported case is for 49 years old gentleman, known to have hypertension, hypothyroidism and Alkaptunurea. He presented to our facility with long standing bilateral knee pain (more in the left) with difficulty in doing daily activities. He presented to our tertiary facility after failure of previous treatment measures. The patient underwent uncomplicated Robotic assisted total knee arthroplasty that resulted in significant improvement of his pain and function. CONCLUSION: Knee arthroplasty is a reliable and reproducible modality in treating Ochronotic knee arthropathy and it would result in pain reduction and better function of patients with such condition.