dagger signJoe Segen2016-11-12T11:31:30+00:00
(1) A term referring to a single central radiodense line on frontal radiographs related to ossification of supraspinous and interspinous ligaments, corresponding to the lumbar spine in bony
dagger sign in vertebral column
fusion of the adjacent vertebrae with syndesmophyte formation, which is characteristic of ankylosing spondylitis.
Synonym Lumbar dagger
(2) A feature seen in imaging in patients with ossification of the posterior longitudinal ligament–OPLL with spinal cord compression due to a dense, vertical ossified 1-5 mm wide strip or plaque at the posterior margin of the vertebral body and intervertebral disks; usually in the cervical spine, ossification may appear at T4 to T7.
Note: OPLL may be distinct from spondylosis deformans and ankylosing spondylitis or a permutation of the DISH complex, see there