injuries poisoning
Spinal Trauma
Etiology of Spinal Trauma
During a typical year, there are about 18,000 spinal cord injuries in the United States or 54 cases per million persons per year ( Etiology reference ). causes of spinal cord injuries are as follows ( Etiology reference ): Motor vehicle crashes (39%) Falls (32%) The remainder of spinal cord injuries are attributed to assault (13%), sports (8%), and work-related injuries ( Etiology reference ). About 78% of patients are male ( In older patients, falls are the most common cause. Osteoporotic bones and degenerative joint disease may increase the risk of cord injury at lower impact velocities due to angulations formed by the degenerated joints, osteophytes impinging on the cord, and brittle bone allowing for easy fracture through critical structures. Spinal cord injuries occur when blunt physical force damages the vertebrae, ligaments, or disks of the spinal column, causing bruising, crushing, or tearing of spinal cord tissue, and when the spinal cord is penetrated (eg, by a gunshot or a knife wound). Such injuries can also cause vascular injury with resultant ischemia or hematoma (typically extradural), leading to further damage. All forms of injury can cause spinal cord edema, further decreasing blood flow and oxygenation. Damage may be mediated by excessive release of neurotransmitters from damaged cells, an inflammatory immune response with release of cytokines, accumulation of free radicals, and apoptosis. Vertebral injuries may be Fractures, which may involve the vertebral body, lamina, and pedicles as well as the spinous, articular, and transverse processes Dislocations, which typically involve the facets Subluxations, which may involve ligament rupture without bony injury In the neck, fractures of the posterior elements and dislocations can damage the vertebral arteries, causing a syndrome resembling a brain stem stroke. Unstable vertebral injuriesare those in which bony and/or ligamentous integrity are disrupted sufficiently that free movement can occur, potentially compressing the spinal cord or its vascular supply and resulting in marked pain and potential worsening of neurologic function. Such vertebral movement may occur even with a shift in patient position (eg, for ambulance transport, during initial evaluation).Stable vertebral fracturesare able to resist such movement. Specific injuries typically vary with mechanism of trauma. Flexion injuries can cause wedge fractures of the vertebral body or spinous process fractures. Greater flexion force may cause bilateral facet dislocation, or if the force occurs at the level of C1 or C2, odontoid fracture, atlanto-occipital or Atlantoaxial Subluxation , or both fracture and subluxation. Rotational injury can cause unilateral facet dislocation. Extension injury most often causes posterior neural arch fracture. Compression injuries can cause burst fractures of vertebral bodies. The lower tip of the spinal cord (conus medullaris) is usually at, or above, the level of the L1 vertebra. Spinal nerves below this level comprise the cauda equina. Thus, findings in spinal injuries below this level may mimic those of spinal cord injury, particularly conus medullaris syndrome (see table). 1.National Spinal Cord Injury Statistical Center:Facts and Figures at a Glance. Birmingham, AL: University of Alabama at Birmingham, 2019. 