Posterior longitudinal ligament

Fig. 20.10. Classification of growth plate injuries. Type 1 There is complete separation of the physis from the underlying vertebral body. Associated tears of the anterior longitudinal ligament (ALL) and posterior longitudinal ligament (PLL) result in vertebral displacement. The intervertebral disc is intact in this type of injury. Type 11 There is incomplete separation of the physis along with a corner fiake of the vertebral body. The intervertebral disc is intact. Type III This injury is a combination of physeal and intervertebral disc injury. In Type lllA, the PLL is torn but the ALL is preserved. In Type IIIB, the ALL is torn but the PLL is intact. Type IV There is a fracture of the vertebral body that traverses the physis and the intervertebral disc...

Type 2 and 3 apophyseal injuries as described by Takata et al. (1988) may be associated with avulsion of the posterior longitudinal ligament. 

Nervous system Neurological complications of fiuoride occur in 10% of patients, mostly in the late stages of fluorosis [60 ]. High cervical myelopathy caused by ossification of the posterior longitudinal ligament and ligamentum flavum has been reported in a patient from an area endemic for skeletal fluorosis [61 ]. 

The posterior longitudinal ligament runs down the posterior surfaee of all vertebral bodies. 

During flexion, the interspace between vertebrae increases posteriorly. The inferior artieular process of the superior vertebra glides anteriorly and superiorly. Motion in the flexed spine is limited by the tension developed in the interspinous ligaments, the ligamenta flava, and the posterior longitudinal ligament. 

Herniated disks are most eommon in the lower lumbar region beeause of narrowing of the posterior longitudinal ligament, the increased ineidence of degenerative disk disease, ligament... 

The spinal portion of the dura is continuous with the inner layer of the cranial dura. Only one layer extends into the spinal canal. The other layer Is continuous with the periosteum of the outside of the cranium. The spinal dura surrounds the spinal cord within the spinal canal. There are many attachments within the spinal canal. Firm attachments of spinal dura Include the foramen magnum, the posterior aspect of the dens, the posterior aspect of the body of C3, the posterior aspect of the body of 52, the posterior aspect of the coccyx via the filum terminate, and minor fibrous slips to the posterior longitudinal ligament along the entire spine, most predominant in the lunar area. 

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