Lumbar spine changes include hyperostosis along the anterior aspect of the vertebral bodies. With progression, cloud-like increased bone density and pointed body excrescences develop. Additional findings that can occur are close apposition of spinous processes or ossification of interspinous ligaments, mild to moderate disc space narrowing, and apophyseal joint space narrowing and sclerosis. Due to the ossification of the calcification and ossification of ligaments which can include the joint capsule, foraminal and central stenosis can occur at any spinal level. In the cervical spine, bony prominence may become so extensive that a thick bony plate is formed anteriorly and may cause dysphagia.
Alterations can occur on the posterior aspect of vertebral bodies, most often in the cervical spine.
These radiographic features include osteosclerosis of the posterior vertebral margin, posterior vertebral osteophytosis, and calcification or ossification of the posterior longitudinal ligament. Cervical myelopathy and cord compression has been associated with patients demonstrating bony proliferation along the posterior aspect of the vertebral bodies. Extraspinal manifestations of DISH are not uncommon and may even be present in absence of significant spinal changes. These extraspinal changes consist of hyperostosis at sites of tendon and ligament attachment to bone, para-articular osteophytes, and ligament ossification. Generally in the peripheral skeleton, periosteal spurs arising at the site of osseous attachment of the tendon are more prominent than true calcification of the tendon itself.