Lumbar spinal stenosis associated with alkaptonuria: Case report

Abstract

Alkaptonuria is a rare autosomal recessive metabolic disorder caused by a deficiency of the homogentisic acid oxidase enzyme. In this disease, degenerative changes occur in the intervertebral discs and connective tissue due to pigment accumulation. This report presents a 45-year-old female patient who developed multi-level lumbar spinal stenosis due to alkaptonuria and underwent surgical treatment. Clinical findings, radiological imaging, and characteristic pigment accumulation observed during surgery were discussed. In this patient with severe spinal stenosis unresponsive to conservative treatment, surgical decompression provided significant improvement in symptoms, while intraoperative black disc material and pigmented ligamentum flavum provided important clues for diagnosis. As spinal degeneration associated with alkaptonuria can be aggressive, these cases should be followed up regularly over the long term.