الفهرس 
ANATOMY OF THE CERVICAL SPINEOnly 14 pages are availabe for public view
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Abstract
Approximately 5-10% of unconscious patients who present to the ED as the result of a motor vehicle accident or fall have a major injury to the cervical spine. Cervical spine injuries cause an estimated 6000 deaths and 5000 new cases of quadriplegia each year. Most cervical spine fractures occur predominantly at 2 levels. One third of injuries occur at the level of C2, and one half of injuries occur at the level of C6 or C7. Most fatal cervical spine injuries occur in upper cervical levels, either at craniocervical junction C1 or C2.
Spinal trauma and spinal cord injuries are a major cause of disability in today’s society, and skill in management of patient with a possibly serious closed neck injury is of great importance. The cervical spine is the most mobile portion of the spine. Its motion is controlled by the geometry of the surfaces and ligaments and their elastic properties. Most commonly, fracture or fracture dislocation of the cervical spine involves excessive flexion, extension or impaction of the spine as a result of a blow to the head. Most patients have sustained trauma from automobile accidents or sport injuries, as well as falling from height.
The cervical spine could be compared to a catapult. The anchor point of the catapult arm is the cervicothoracic junction, and at the end of the catapult arm is a heavy projectile, the occiput.
An accurate classification system is important in identifying common fracture patterns, determining prognosis, and assisting the physician in planning reduction maneuvers and determining proper treatment methods. On the basis of anatomic differences the cervical spine is divided into upper and lower cervical spine.
The upper cervical spine fractures can be
• Occipital condyles fractures
• Atlas fractures
• Odontoid fractures
• Traumatic spondylolisthesis of the axis
• Miscellaneous C2 fractures (spinous process, lamina, lateral mass and vertebral body fractures).
A commonly used classification of lower cervical spine injuries identifies six categories of injuries which are:
• Compression flexion
• Distraction flexion
• Compression extension
• Vertical compression
• Distraction extension
• Lateral flexion
The normal anatomy of the cervical spine consists of 7 cervical vertebrae separated by intervertebral disks and joined by a complex network of ligaments. These ligaments keep individual bony elements behaving as a single unit. The cervical spine considered as 3 distinct columns: anterior, middle, and posterior. Column disruption may lead to mechanical instability of the cervical spine. The degree of instability depends on several factors that may translate into neurologic disability, secondary to spinal cord compression.
Cervical spine injuries are best classified according to several mechanisms of injury. These include flexion, flexion-rotation, extension, extension-rotation, vertical compression, lateral flexion.
Clinical evaluation of the cervical spine in a patient with blunt trauma is unreliable. In a study of surgical residents’ ability to predict cervical injuries on the basis of clinical examination alone, sensitivity and specificity were 46% and 94%, respectively. Because of these limitations and potential for catastrophic morbidity if injury is missed, most patients with complex blunt trauma seen in the ED undergo radiographic evaluation before clearance, and some may need further evalution by CT scan and MRI.
When a cervical spine injury is suspected, minimize neck movement during transport to the treating facility. Ideally, transport the patient on a backboard with a semi rigid collar, with the neck stabilized on the sides of the head with sand bags or foam blocks taped from side to side (of the board), across the forehead, management of cervical spine fractures varies according to type of fracture, instability and presence of cord compression from external fixation to surgical decompression and internal fixation.
Neurological dysfunction following traumatic cord injury is a result of both an initial mechanical insult and ongoing biomechanical, pathological, and immunological process that disrupt normal cord anatomy and function.
The clinical findings of cervical injuries may be as simple as neck pain and tenderness or serious as complete or in-complete cord injury or nerve root injuries. Diagnosis of spine injury relies on symptoms and signs of pain in the spine with sensory loss and disturbances in motor function distal to a neurological level. The pain may radiate owing to nerve root irritation. A full neurological examination must be performed. Care full systemic X-ray examination by standard radiographs. CT studies and occasionally MR imaging studies are essential for determining the precise nature of each injury and for guiding subsequent therapy.
The initial management of patients with suspected cervical spine trauma is the same for any victim of a major trauma. Current intervention includes systemic delivery of high dose methylprednisolone, early reduction, decompression and stabilization. These interventions are geared toward preventing further neurological deficit and promoting segmental improvement. Cervical instrumentation and fusion serve as important adjuvant in stabilizing the traumatized cervical spine. Internal fixation with instrumentation enables the surgeon to realign and fix the spine in a rigid fashion.