Ace Your Spinal Exam 4 Practice 2026 – Get Ready to Flex Your Brain!

The key idea is that ossification of the posterior longitudinal ligament tends to happen most often in the cervical spine. The cervical region bears a lot of movement—flexion, extension, and rotation—and the forces here promote degenerative and metaplastic changes in the posterior longitudinal ligament. This region also has a relatively high susceptibility to metabolic and genetic factors associated with PLL ossification, and changes can narrow the spinal canal enough to cause myelopathy.

In contrast, the thoracic region is more rigid due to the rib cage, which limits motion and makes ossification less common there, and the lumbar and sacral regions are less prone to this process for similar biomechanical reasons. Therefore, the cervical spine is the usual site for ossification of the posterior longitudinal ligament.