Ochronosis and lumbar disc herniation.

Alkaptonuria is a rare, autosomal recessive metabolic disorder in which the homogentisic acid oxidase activity is absent. Its incidence is as low as 0.001%. Ochronosis is the pigmentation of connective tissues and this pigmentation leads to degenerative changes in alkaptonuric patients. Alkaptonuria most prominently involves the lumbar region, but lumbar disc herniation as the presenting feature of alkaptonuria is not common. Only a few patients required surgical intervention. Herewith we report an alkaptonuric patient, who was operated on for lumbar disc herniation. His discectomy material was black and the metabolic disorder was diagnosed retrospectively. This metabolic disease is often recognized on physical re-examination after the black disc material was seen during the operation. Therefore urinalysis for homogentisic acid should be performed in all patients with degenerative changes of the vertebral column. The results of disc surgery in this patient group is successful.