Ochronosis of the Lumbar Spine: A Case Report and Review of Literature

Alkaptonuria is an uncommon genetic condition inherited in an autosomal recessive pattern, characterised by a disruption in the metabolism of phenylalanine and tyrosine, leading to insufficient levels of the enzyme homogentisate and further causes a buildup of Homogentisic Acid (HA). This further leads to blackish discolouration of connective tissues where the acid accumulates. Initially, manifesting as alkaptonuria, it progressively develops into ochronotic arthropathy, which primarily affects the large joints and vertebral discs. Spinal involvement can lead to kyphosis, reduction in height, decreased lumbar flexibility, limited range of motion, and joint effusions. We present a case of a female in her late sixties with complaints of pain in her lower back radiating to her bilateral thighs. Past history revealed dark urine stains on her clothes; she underwent bilateral total hip arthroplasties. On further investigation, she was diagnosed with lumbar disc herniation secondary to ochronosis of the spine. The patient was taken up for L4-L5 decompression. Postoperatively, the patient had improvement of symptoms with no new complaints. We have also included a concise literature review of spinal ochronosis, emphasising the diagnostic hurdles and therapeutic methods associated with this rare condition.