Unstable Spine Injuries Research Articles

Optimal Positioning for Cervical Immobilization

Study objective: We hypothesized that optimal positioning of the head and neck to protect the spinal cord during cervical spine immobilization can be determined with reference to external landmarks. In this study we sought to determine the optimal position for cervical spine immobilization using magnetic resonance imaging (MRI) and to define this optimal position in a clinically reproducible fashion. Methods: Our subjects were 19 healthy adult volunteers (11 women, 8 men). In each, we positioned the head to produce various degrees of neck flexion and extension. This positioning was followed by quantitative MRI of the cervical spine. Results: The mean ratio of spinal canal and spinal cord cross-sectional areas was smallest at C6 but exceeded 2.0 at all levels from C2 to T1 ( P<.05). At the C5 and C6 levels, the maximal area ratio was most consistently obtained with slight flexion (cervical-thoracic angle of 14 degrees ) ( P<.05). For a patient lying flat on a backboard, this corresponds to raising the occiput 2 cm. More extreme flexion or extension produced variable results. Conclusion: In healthy adults, a slight degree of flexion equivalent to 2 cm of occiput elevation produces a favorable increase in spinal canal/spinal cord ratio at levels C5 and C6, a region of frequent unstable spine injuries. [De Lorenzo RA, Olson JE, Boska M, Johnston R, Hamilton GC, Augustine J, Barton R: Optimal positioning for cervical immobilization. Ann Emerg Med September 1996;28:301-308.] See related editorial, p 351.

A comparison of the spinal board and the vacuum stretcher, spinal stability and interface pressure

The interface pressures were measured between the sacrum, mid-lumbar spine and various support surfaces. Thirty healthy male volunteers were recruited. The spinal board, padded spinal board and vacuum stretcher were the support surfaces evaluated. We found high and potentially ischaemic pressures between the sacrum and the spinal board interface (mean 747.3 mmHg). This was reduced in the padded board (115.5 mmHg) but dramatically reduced with the vacuum stretcher (36.7 mmHg). It was also noted that no support was given to the normal lumbar lordosis by the spinal board (padded and unpadded), but support was given by the vacuum stretcher. This raises the question of how stable is an unstable spinal injury on a flat supporting surface.

Clinical Guidelines for Delayed or Prolonged Transport: III. Spine Injury

Conventional emergency medical services (EMS) guidelines recommend that essentially every victim of any significant trauma be treated in the field as having an unstable spine injury. For example, any victim of any motor vehicle crash generally is assumed to have an unstable spine injury and is transported to the hospital in full-spine immobilization. This approach generally is reasonable and appropriate for the conventional EMS context of rapid transport, because patient symptoms and physical examination often are unreliable for the time period immediately following the event.The specialized context of delayed or prolonged transport, however, requires a closer look at assessment criteria and treatment procedures for spine injury. Full-spine immobilization, if it is not required, can be unnecessarily difficult, impractical, impossible, and even dangerous during prolonged evacuation, especially in severe environments or when using improvized equipment. Prolonged transport also provides an opportunity to repeat patient surveys and to observe changes in the patient's condition over time.

The Sternal-Rib Complex

Two cases are described in which displaced sternal fractures were associated with thoracic spine fractures of minimal, initial displacement. Nonoperative, expectant treatment led to significant kyphotic deformity. It is postulated that the sternum and ribs represent a fourth column of structural thoracic spine support. An overriding, displaced sternal fracture is a marker for a severe flexion-distraction unstable thoracic spine injury with a propensity for deformity.

Clinical predictors of unstable cervical spinal injury in multiply injured patients

All victims of major blunt trauma have been said to be at risk of cervical spinal injury. In a prospective study of 410 such patients at our institution, we idenitfied 13 patients (6.12 per cent) with unstable cervical spines. Loss or defect of consciousness following injury (regardless of duration), neurological deficit consistent with cervical cord or nerve root injury and neck tenderness were significantly predictive of an unstable cervical spine. Immediate radiographic investigation of the cervical spine is mandatory in such patients, but may not be required in patients without these signs.

Herniated Intervertebral Discs Associated with Unstable Spinal Injuries

To examine the occurrence of traumatic herniated intervertebral discs associated with unstable spinal injuries, the authors reviewed the records of all patients with spinal cord level unstable spine injuries managed at their institution over a 26-month period. Ninety-three patients were identified. All patients had roentgenographic and computed tomographic (CT) evaluation. Magnetic resonance imaging was performed in 48 patients, and revealed the presence of a herniated intervertebral disc in 16, with the highest incidence being in the cervical spine. In the patients who had only plain film and CT scans, no disc pathology was identified. Magnetic resonance imaging provides a noninvasive means of examining intervertebral disc damage in unstable spinal injuries that might otherwise be unidentified and result in spinal cord injury at the time of surgery.

Spinal cord concussion

The hallmark of concussion injuries of the nervous system is the rapid and complete resolution of neurological deficits. Cerebral concussion has been well studied, both clinically and experimentally. In comparison, spinal cord concussion (SCC) is poorly understood. The clinical and radiological features of 19 SCC injuries in the general population are presented. Spinal cord injuries were classified as concussions if they met three criteria: 1) spinal trauma immediately preceded the onset of neurological deficits; 2) neurological deficits were consistent with spinal cord involvement at the level of injury; and 3) complete neurological recovery occurred within 72 hours after injury. Most cases involved young males, injured during athletics or due to falls. Concussion occurred at the two most unstable spinal regions, 16 involving the cervical spinal and three the thoracolumbar junction. Fifteen cases presented with combined sensorimotor deficits, while four exhibited only sensory disturbances. Many patients showed signs of recovery with the first few hours after injury and most had completely recovered within 24 hours. Only one case involved an unstable spinal injury. There was no evidence of ligamentous instability, spinal stenosis, or canal encroachment in the remaining 18 cases. Two patients, both children, suffered recurrent SCC injuries. No delayed deterioration or permanent cord injuries occurred. Spinal abnormalities that would predispose the spinal cord to a compressive injury were present in only one of the 19 cases. This suggests that, as opposed to direct cord compression, SCC may be the result of an indirect cord injury. Possible mechanisms are discussed.

Spinal fractures in blunt chest trauma.

In a series of 100 consecutive patients with mediastinal hemorrhage following blunt chest trauma, fractures and dislocations of the lower cervical, thoracic, and upper lumbar spine were causative of the mediastinal hemorrhage in nine patients. Spinal injury was clinically suspected in seven patients because of quadriplegia or paraplegia. However, in the two patients who were neurologically intact a spinal injury was not clinically suspected. In the initial triage of a patient with blunt chest trauma, the supine chest radiograph can play a key role in the identification of a potentially unstable spinal injury and the prevention of subsequent spinal cord injury.

Stabilization of the Lower Thoracic and Lumbar Spine with External Skeletal Fixation

For stabilization of the lower thoracic and lumbar spine, an external spinal skeletal fixation (ESSF) system has been developed and clinically used since 1977. The system consists of two pairs of Schanz screws and an adjustable external fixation device. The Schanz screws are firmly anchored through the pedicles into the vertebral bodies. Application of ESSF offers some unique characteristics beneficial in the treatment of unstable spinal injuries and spinal osteomyelitis. In contrast to other fixation systems, the number of vertebrae immobilized can be reduced with ESSF. Versatility of the system allows application in every type of spinal instability. Stability obtained with ESSF suffices for early mobilization without major external support in every instance. In laboratory investigation, ESSF proved to be more secure than rod distraction systems and plate fixation. Since 1977, 65 patients were treated with ESSF. All 52 patients who were at least one year postsurgery were personally examined. This group included 42 patients with acute spinal trauma and eight patients with spinal osteomyelitis. Results achieved with ESSF have been encouraging, with no serious complications to date. Future modifications of ESSF application could lead to simplification and facilitation of treatment.

A locking hook-spinal rod: current status of development

A locking hook spinal rod previously demonstrated to be sufficiently stable and strong in cadaver experiments has been employed in 30 unstable thoraco-lumbar spinal injuries with results superior to Harrington instrumentation.

Open reduction of unstable thoracolumbar spinal injuries and fixation with Harrington rods

The results of treatment of sixteen patients with unstable thoracolumbar spinal injuries are recorded. Early open reduction, stabilization with Harrington rods, spine fusion, application of a plaster jacket until consolidation, and early mobilization was the treatment. Distraction rods were used in twelve patients and compression rods, in four. Nine patients with incomplete paraplegia showed marked neurological recovery, while five with complete paraplegia regained only some sensation. Two patients had no neurological involvement. Solid fusion was achieved in fifteen patients after a minimum of three months of plaster-cast immobilization. In one patient stabilization failed. There was a loss of 5 degrees on average (range, 2 to 23 degrees) in the correction of the kyphosis. Lateral angulation after surgery did not occur. The treatment allowed easier postoperative nursing and early mobilization of the patient.