Diffuse Idiopathic Skeletal Hyperostosis Widespread calcification and ossification of the anterolateral ligaments of the spine, which may give rise to ankylosis. Widespread calcification and ossification of the anterolateral ligaments of the spine are characteristic and may result in bony ankylosis. The pathogenesis is unknown. Some studies have found a possible link to increases in the plasma concentrations of insulin and growth hormone. Pain may be noted years before x-ray manifestations appear.
Physical examination shows few abnormalities.
Thoracolumbar and cervical spine mobility may be mildly or moderately decreased, and tenderness may be present over the thoracic spine. Occasionally, anterior cervical osteophytes can be palpated at the posterior aspect of the pharynx. Later in the disease, rheumatic abnormalities are extensive, but pain is often minimal and spinal motion is only moderately limited. Advanced ligamentous calcification can be seen in the iliolumbar and patellar ligaments. Periarticular osteophytes are usually conspicuous.