Non-inflammatory enthesopathies of the spine: a diagnostic approach.

Ankylosing vertebral hyperostosis, or hyperostotic disease, is an ossification of the entheses, the regions of insertion of tendons, ligaments or joint capsules into the bone. These ossifications create intervertebral bridges (ossifications of the common anterior, lateral and posterior intervertebral ligaments as well as of the ligamentum flavum), which are responsible for the potential signs of the disease: back and neck pain and stiffness, spinal cord compression at the cervical level and lumbar canal stenosis at the lumbar level. The bony epiphyses are the sites of bony appositions, or enthesophytes, which may compromise joint mobility and increase the risk of secondary osteoarthritis, causing hip and knee disorders in particular. These degenerative joint diseases may eventually necessitate total replacement. In this case, the risk of re-ossification around the prosthesis must be averted by the immediate postoperative prescription of anti-inflammatory medication for 1-2 weeks.