Diffuse Idiopathic Skeletal Hyperostosis eMedicine Orthopaedics

Description: Diffuse idiopathic skeletal hyperostosis (DISH) describes a phenomenon characterized by a tendency toward ossification of ligaments. It most characteristically affects the spine. Ossification of the longitudinal ligaments (especially the anterior ligaments) of the spine produces a tortuous paravertebral mass anterior to and distinct (at least radiologically) from the vertebral bodies. Grossly, the appearance is that of candle wax dripping down the spine. While the thoracic anterior longitudinal ligament is ossified, the areas of ossification often meet without fusion. Motion actually is possible, in contrast to lumbar vertebral bridging, which is associated with loss of lumbar motion. The zygapophyseal and sacroiliac joints are not involved in DISH, and the intervening intervertebral disk space is preserved.