Multiple vacuum discs, and early sign of ochronosis. Radiologic findings in two brothers.

Two brothers with ochronosis are reported and the radiological features of ochronotic vertebral disease are reviewed. A striking feature was the presence of multiple vacuum discs. This "vacuum phenomenon" constitutes one of the earliest radiologic changes in the spine and presumably represents areas of severe degeneration within the intervertebral discs. Other features included a dark pigmentation of the urine after standing or following the addition of sodium hydroxide, and calcification within the cartilages of the ears and intervertebral discs. There was no abnormality of the peripheral joints and pigmentary deposits in the ears, sclerae, or skin were not observed.