Spinal Trauma: Injury, Damage, and Management

Spinal Trauma

• Traumatic spine injury (TSI) is potentially life-threatening, with severity dependent on the injury location and damage to nearby structures
• Spinal cord injuries result from high-energy forces but may occur from low-energy mechanisms in vulnerable populations
• Injury to spinal components may not damage the spinal cord, and the spinal cord, vessels, and nerves may be damaged without fractures or dislocations
• Damaged structures and ligaments can cause vertebral column instability, making the spinal cord susceptible to injury if motion isn't restricted
• Severe injuries may irreparably damage the spinal cord, causing lifelong disability
• Immediate spinal cord damage is primary injury; secondary injury can worsen the neurologic deficit, exacerbated by pathologic motion from an injured spinal column
• Recognizing and managing these injuries is important for timely stabilization, guiding diagnostic and management decisions, and reducing secondary injury risk

Force on the Spine

• Sudden violent forces can stress spinal structures beyond their normal limits
• Objects in motion stay in motion, and objects at rest stay at rest
• The head's mass moves differently from the torso, applying strong forces to the neck
• Upper leg movement displaces the pelvis, forcefully moving the lower spine with contra force in the upper spine
• Lack of neurologic deficit doesn't rule out bone or ligament injury or conditions that stress the spinal cord to its limit

Epidemiology of Spinal Injuries

• Approximately 17,900 people in the U.S. (54 per 1 million) sustain SCI annually, with 252,000 - 373,000 living with disability
• Incidence of SCI is increasing in the population aged 65 years and older
• There has been a significant increase in SCI from falls between 1997 and 2012
• Unintentional falls accounted for 40% of acute traumatic SCIs in the United States in 2012
• Males account for over 78% of SCIs
• Common causes of SCI include:
  • Motor vehicle crashes (39%)
  • Falls (32%)
  • Penetrating injuries (14%)
  • Sports injuries (8%)
  • Other injuries (7%)
• In older adults, falls outnumber car crashes as the primary cause of SCI
• SCI affects physical function, lifestyle, and finances, and generally reduces life expectancy
• SCI can be complete, affecting both sides of the body with total loss of function below the injury, or incomplete, with preserved but asymmetric function
• Upper cervical spine injuries are most devastating

Types of Spinal Injury (SCI)

• SCI can have different degrees and presentations ranging from mild weakness to requiring a wheelchair or ventilator
• Significant changes to activity levels and independence and financial circumstances may occur
• The lifetime cost of care ranges from $1.2 to $5.2 million per patient, increasing with injury severity and younger age at injury
• Neurologic deficits can result from trauma to the nervous system(s), inadequate oxygenation/perfusion, or multiple organ injuries, emphasizing comprehensive patient care
• Spinal injury should be considered in any blunt mechanism that produced a violent impact on the head, neck, torso, or pelvis.
• Incidents producing sudden acceleration, deceleration, or lateral bending forces require consideration.
• Falls from height, ejection from motorized devices, and shallow-water diving incidents also necessitate consideration of spinal injury.

Spinal Motion and Stabilization

• Prehospital spinal immobilization using rigid backboards has evolved since its popularization in the 1960s
• Spinal motion restriction is decided after considering the mechanism of injury, comorbidities, risk factors, and physical examination
• Understanding the limitations and complications of spinal motion restriction is important
• The safety and efficacy of using the tradition rigid long backboard has been challenged
• Evolution in prehospital management of spine trauma has generated widespread adoption of evidence-based protocols for spinal motion restriction and management of acute SCI
• These protocols aim to reduce complications by restricting motion with a backboard while efficiently limiting motion in those with injured spines
• The patient with suspected spinal injury should be manually stabilized in a neutral in-line position until the need for continued spinal motion restriction has been assessed

Anatomy and Physiology

• The vertebral column comprises 33 bones called vertebrae which facilitates movement and disperses forces from the head and trunk to the pelvis, also shielding the spinal cord
• The body of each vertebra is situated anteriorly and bears most of the weight of the vertebral column
• The neural arches are formed by the pedicle and posteriorly by the lamina projecting back from the body
• The spinous process is a midline bony protuberance from the posterior aspect of the lamina and points posterior to caudal (downward direction).
• Each vertebrae has a pair of facet joints covered in cartilage and allow articulation with one another.
• The transverse processes arise laterally from the junction of pedicles and vertebral bodies and allow attachment of paraspinal muscles
• Neural and vascular structures pass through the intervertebral foramen between each pair of vertebrae
• The spinal cord passes through the vertebral foramen (spinal canal)

Vertebral Column Regions

• Vertebrae are stacked in a S-shaped column of cervical, thoracic, lumbar, sacral and coccygeal regions
• Cervical vertebrae support the head and form the skeletal component of the neck, and are flexible to allow head movement
• The vertebral arteries that supply the posterior aspect of the brain run through foramina in the cervical vertebra, usually entering at C6. If displaced, stroke like symptoms may present
• The cervical spine has unrestricted mobility and is most commonly injured
• Thoracic vertebrae each connect with a pair of ribs and the thoracic spine is more rigid with less movement than the cervical spine
• Because of the stability the increased stability that the ribs provide, the thoracic spine typically requires significant physical forces for injury
• The lumbar spine is flexible
• The sacral and coccygeal vertebrae fuse

Spinal Cord Anatomy

• The spinal cord has three membranes: the pia, arachnoid, and dura mater which are known as the meninges
• The space between the pia and the arachnoid mater contains cerebrospinal fluid (CSF), which cushions the brain and spinal cord
• The spinal cord consists of gray matter, primarily neuronal cell bodies, and white matter, long myelinated axons that make up the spinal tracts
• Spinal tracts are divided into ascending (sensory impulses) and descending (motor impulses)
• Ascending tracts for pain and temperature decussate in the spinal cord, while those for position, vibration, and light touch cross over cranially
• Descending tracts manage muscle movement and tone and do not cross over in the spinal cord, but in the brain stem
• The spinal cord has 31 pairs of spinal nerves, each with dorsal (sensory) and ventral (motor) roots that pass through the intervertebral foramen
• A dermatome is the sensory area on the skin innervated by a single dorsal root, showing the areas of the body and their level on the spine
• Landmarks include clavicles (C4-C5 dermatome), nipple level (T4), and umbilicus (T10)

Pathophysiology of Injured Spines

• The spine can withstand forces of 1,000 foot-pounds of energy
• High-speed travel and contact sports can exert forces beyond that
• Even low- to moderate-speed vehicle crashes can place 3,000-4,000 foot-pounds of force against the spine if the head is suddenly stopped
• Cervical injury has the highest risk of associated injury to other structures
• Cervical 65%, lumbar 52% and thoracic 50%
• Injuries in the thoracic spine should raise index of suspicion for lung, diaphragm, ribs, or sternum injury
• The risk of associated injury increases with increasing the number of fractures or injured segments

Types of Skeletal Injuries

• Compression fractures which produce wedge compression or total flattening of the body of the vertebra

• Burst fractures that can violate the posterior vertebral wall and may produce small fragments of bone that may lie in the spinal canal near the cord

• Subluxation which is a partial dislocation of a vertebra from its normal alignment in the spinal column

• Discoligamentous injury which results from over-stretching or tearing of the ligaments and muscles, producing instability between the vertebrae with or without bony injury

• Simple compression fractures are usually stable

• Some patients can have unstable injuries that don't cause immediate issues but may cause secondary damage, thus, the entire spine should be surveyed with a potential injuries

• If the presence of good motor and sensory responses indicates that the spinal cord is intact does not rule out bony, ligamentous, or soft injury

Mechanisms of Injury and Spinal Cord Injuries (SCI)

• Axial loading happens during driving incidents, or falling
• Falls greater than 15ft can cause lumbar spine fracture, and less in older adults
• Axial loading can exaggerate normal curvatures and cause fractures/ compressions
• Vertebral bones can suffer tensile, flexion, extension, and lateral compromise, which can produce vertebral fractures
• Distraction can occur when one part is stable and the other is in longitudinal motion e.g. playground injuries or hangings
• SCI related to physical abuse often cause injury in pediatric patients
• Determining an exact mode of failure of the spinal column is hard
• Primary injury can include a direct SCI, cord compression and or disruption of cord blood flow
• Cord concussion comes from temporary disruption of cord functions to the spinal cord

Types of Cord Injuries

• Cord compression: pressured caused by swelling of local tissues, requires prompt transport
• Cord laceration: Spinal cord tissue is torn or cut. Usually results in nonreversible neurologic injury
• Spinal cord transection: Can be complete or incomplete, prognosis for recovery is greater when the injury is incomplete
• Cord contusion: Bruising and bleeding of the spinal cord, needs care based off level of injury
• Spinal Shock: neurologic phenomenon that happens after a spinal cord injury, causing loss in sensory and motor, flaccidity and paralysis
• Important to evalute and manage SCI patients without thinking about what kind of SCI they sustained

Incomplete Cord Injuries

• Anterior cord syndrome involves loss of motor function and pain, temperature, and light touch sensations; light touch, motion, position, and vibration sensations are spared through the intact posterior column

• Central cord syndrome involves weakness/ paresthesia in the upper but less in the lower extremeties, can lead to bladder dysfcn

• Brown-Séquard syndrome: caused by hemi-transection involving in only one side, can cause loss of spinal cord dmange and loss of function of the affected side

• Spinal shock is contrasted by neruogenic shock (type of distributive shock)

• Neruogenic can be discrimiated from loss of motor function

Spinal Cord Perfusion

Spinal cord blood flow is partially determined by spinal cord perfusion pressure (SPCC):

• SCPP = Mean Arterial Pressure(MAP) - Extrinsic Pressure
  • Several factors effect it: ex: MAP and spinal venous congestion, as well as spinal hypoxia
• MAP: the MAP primarily determines cord perfusion
• Spinal Venous Congestion: can be effect of venous thrombosis OR from extrinsic compression of spinal veins causing inadequate blood outflow
• Hypoxia: from pulmonary issues can result in low partial pressure

Initial Resuscitation After SCI

• Aggressive resuscitation reduces neurologic deficit and prevents secondary damage. Can include vasopressors and pacemakers
• Early BP and volume augmentation can help
• Goal MAP: 85 mm Hg
• Use crystalloids, colloids, or blood products through venous access for neurologic blood flow
• Volume based resuscitation should avoid incl glucose (too much glucose = increased anaerobic cell metabo)
• High SCIs (C5 or above) can cause need for cardiovascular interventions
• The average MAP of patients on scene is in the 60s

Assessment After Injury

• Assessed with consideration for all other conditions present
• Safety then primary survey 1st, determine if spinal column needs protection
• Head is inline, unless is contraindicated
• Head must be stabilized until immobilzed, with a cervical collar and a device like a vaccuum mattres
• Neurologic tests are to move arm and legs etc.

Mechanism of Injury

• One must evalute their LOC, sensory function

• Mechanism of Injury never the SOLE indication of whether something needs spinal motion restrictions Alcohol, drugs, or TBI, can impede reliability

• Spinal restriction is not indicated when there's a reliable exam, no neuro deficits, good movement, and no distracting injury

• Blunt traumas/ crashes are responsible for all spine fxs

• Cervical SCIs have higher risk of neruo impairment

• Presence of spinal injury and a potentially unstable spine needs assessment of the spine to ensure no harm happens

• Penetrating spinal injuries don't cause spinal fx

Spinal Motion Restriction

• The key takeaway: A physical assessment with clinical judgement for determining risk of something.

Considerations For Use

Spinal Motion REstriction should be considered

• blunt mechanisms with indications in Box 9-2
• important signs and symptoms from box 9-3

Spinal Motion Restriction Is Unnecessary

• meets all criteria and listed in Box 9-4

Spinal Cord Injuries

• Primary vs Secondary
• Cord concussion
• Cord compression
• Cord laceration
• spinal cord transection (complete vs incomplete)

Types of incomplete Injuries

• anterior cord
• central cord
• Brown Sequard

Management

• Spinal restrictions should be effective to avoid unnecessary neruo damage
• Devices: can be safe with understanding only
• Spinal device and trauma often requires knowledge with how to work and knowledge of all devices to secure everything to the joint's injury
• Neutral position required, for comfort

Specific details

- Proper sizing (Collar) will keep neck from extending/ improper leads to problems if there's already a problem

• Guidelines for Rigid Cervucal Collard should adequately immobilize someone cooperative

- Torso has to be secured so that there can be stability

• ceaphalod- restrict upper
• caudad- restrict the torso

What about the longboard?

• it helps
• a rigide board was thought to help the overall spine

- in some cases, it helps elevation and can increase pressure in TBI people. A good cervical collar must be considered!

• Usually sitations: Ambulatory and need help vs those w/ mild neck pain

General Precautions

• Move to the In-line position and evalute the patients primary and intervien if needed.
• examine the neck again and apply
• then perform a spinal motion

Manual Interventions

• Contradictions should consider neck or muscle spasms, airway compomise

Rigid Cervical Collars