====== Interspinous distance ======

{{ ::interspinous_distance.png?200|}}

Anterior [[dislocation]] of the [[cervical spine]] may be detected reliably in the [[supine]] frontal projection by evaluating the cervical [[spinous process]]es. A widened [[interspinous distance]] (ISD) which measures more than one and one-half times the ISD above and more than one and one-half times the ISD below indicates the presence of an [[anterior cervical dislocation]] at the level of abnormal widening. Measurements of the interspinous distances from the [[C3]]-[[C4]] interval through the [[C7]]-T1 interval in 500 patients with normal [[cervical spine]]s and in 14 patients with documented anterior cervical dislocations revealed neither [[false positive]] nor false-negative diagnoses by these criteria
((Naidich JB, Naidich TP, Garfein C, Liebeskind AL, Hyman RA. The widened
interspinous distance: a useful sign of anterior cervical dislocation in the
supine frontal projection. Radiology. 1977 Apr;123(1):113-6. PubMed PMID: 847132.
)).
----
On plain radiographs, a decrease of 50 percent in [[vertebral body height]], an increase of [[interspinous distance]], and greater than 30 to 35 degrees of [[kyphotic deformity]] are suggestive of [[posterior ligament complex injury]].