Learning Radiology xray montage


  • Rare hereditary disorder

    • More common in males 2:1

  • Insufficiency of homogentisic acid oxidase

  • Results in excessive homogentisic acid excreted in urine and deposited in soft tissue

  • Urine may be “black”

  •  Sclera may be grey-brown or yellow

  • Cartilage of nose and ears may be bluish in color

  • Clinical findings are combination of spondylitis  and arthritis of major joints

    • When deposited in cartilage, synovial thickening develops

    • This results in:

      • Subchondral cysts

      • Sclerosis

      • Osteophyte production, all secondary to DJD

      • Bony ankylosis may occur in joints or spine

    • Usually affects large joints-knees, shoulders, hips

    • Chondrocalcinosis of appendicular joints may develop

  • In the spine:

    • Changes of degenerative disc disease

    • Ligamentous structures mat be involved

    • Resembles ankylosis spondylitis

    • Universal disc space calcification is common

  • Universal disc calcification and DJD of root joints (hips and shoulders) in younger patient are pathognomonic


  Ochronosis. There is universal disc calcification, a finding that is highly suggestive of ochronosis.

Murray and Jacobson, 2nd ed, vol.2