The continuity of the posterior and anterior longitudinal ligaments (and other ligaments) is an important part of assessment of vertebral column injury.  The continuity, or otherwise, is best seen on an MRI scan.  It gives an indication of the violence of the injury, as well as some guide as to the techniques that can be used in treatment, particularly surgery.

Abnormal ossification of the posterior longitudinal ligament can occur.  This usually presents as cord compression (myelopathy) and is common in the Japanese population.