Spinal Injuries Flashcards
Mechanisms of Injury
1) Penetrating Injury (gunshot, knife wound etc.)
2) Blunt Injury - most common, involves number of forces that occur in combination
Types of Blunt Injury
1) Forced flexion (anterior) or flexion with rotation
2) Forced extension (hyperextension)
3) Vertical compression (axial loading)
The most mobile regions of the spine are
Cervical and the thoracolumbar junction
Are also most common sites of injury
Types of Vertebral Fracture /(7)
Simple Compression or Wedge Communicated or Burst Fracture Teardrop Dislocation Subluxation Fracture Dislocation
Simple Fracture
Generally involves elements of the neural arch (spinous or transverse process)
Compression or Wedge
Anterior compression to the vertebral body
Communicated or Burst
Shattering injury to vertebral body
Likelihood of fragments impinging on spinal cord
Resultant severe damage
Teardrop
Small fragment chipped away from vertebral body
Free to lodge in the spinal canal
Associated with posterior dislocation of the vertebral body
Neurological deficit
Removal of bone fragment if in canal
Subluxation
Partial or incomplete dislocation of one vertebral over another
Fracture Dislocation
Fracture or dislocation with ligament and cord injury
Unstable Spinal Injury
Vertebral and ligamentous structures are not able to support or protect the injured spine
Moment may increase pressure on spinal cord and further neurological deficit
Stable Spinal Injury
Bony and/or ligamentous structures support the injured area sufficiently to prevent progression of the neurological deficit and prevent bony deformity
If posterior elements (ligament between neural arch and the articulating facet joints) survive the injury, it is considered stable
Stability Classification system (Column Concept)
Anterior, Middle and Posterior Columns
Anterior Column
Anterior Longitudinal ligament and anterior 2/3 vertebral body and intervertebral disc
Middle Column
Posterior Longitudinal ligament, posterior 1/3 of the intervertebral disc and posterior wall of the the vertebral body
Posterior Column
Neural arch (lamina, pedicles, and ligamentum flavum), the articular processes and facet joint capsules, the spinous processes and the interspinal ligaments
4 Major Categories of Spinal injuries
Forward flexion (anterior compression fractures)
Flexion- axial compression (burst)
Flexion- distraction injuries (seat belt injuries and chance fractures)
Fracture-dislocation (sheer injuries that cause sagittal or coronal plane translation)
Spinal Injuries with disruption of all 3 columns
are considered to be unstable
C1 Fractures/ Atlas/ Jefferson Fractures
Axial loading through top of the head
Most common cause of disruption of the ring of the C1 vertebra
C2 Fractures / Axis
Most commonly, odontoid process or posterior element damage
Flexion typically the mechanism
Hangman’s fracture is through posterior elements, caused by forced hyper extension
Are C1, C2 fractures commonly associated with neurological deficit?
No
Common Injuries to Sub Axial Cervical Spine (C3-C7)
Most commonly axial load flexion fractures with burst type of injury
OR
Flexion distraction with uni or bilateral locking of the facet joint depending on amount of rotation that occured
Subluxation and relocation without fracture may result in neurological deficit without visual damage, this is more commonly caused by hyperextension injury
Common Injuries to the Thoracic Spine
Usually a fracture or fracture dislocation
Various mechanisms, but most commonly axial loading and flexion with rotation
Anterior compression results in varying degree of posterior protrusion or kyphosis
Thoracolumbar Junction
Susceptible area for spinal injury
Area of stress and increased mobility below rigid rib cage
Associated with flexion and rotational forces with resultant conus and/or cauda equina lesion
A fall will often result in a compression fracture
Lumbar and Sacral
Fractures within these regions resemble those of the thoracolumbar junction
Chance Fractures
Lap belt injury unique to lumbar spine (most commonly L1, L2)
Caused by severe flexion and rotation around a fixed axis (pelvis secured by belt)
Leads to bony and ligamentous disruption to the lumbar spine
Anterior compression to vertebral body
Transverse fracture through posterior elements of the vertebrae
Associated with internal abdominal injuries
Determining Neurological Impairment
Examinations of dermatomes and myotomes together, level of injury may be established, determine what functions remain
Insult to spinal cord, several mechanisms cause progressive damage
Related to mechanical insult
Biochemical responses
Hemodynamic changes, often associated with multiple trauma
Primary Pathological changes after injury
Bleeding and swelling at site of injury can cause severe necrosis of gray matter
Secondary Pathological changes
Associated Biochemical and hemodynamic changes alter physiological response to injure
Changes in systemic blood flow and oxygen tension
May cause impaired CNS function/systemic blood loss, damaging delicate structure of spinal cord
Quad/tetraplegia
Impairment or loss of motor and/or sensory function in cervical segments of spinal cord due to damage of neural elements within canal
Impaired function of arms trunk pelvic organs legs
Does not include brachial plexus lesions or injury to peripheral nerves outside the neural canal
Paraplegia
Impairment or loss of motor and/or sensory function in the thoracic, lumbar, or sacral segments of the spinal cord
Secondary to damage of neural elements within the canal
Arm function spared depending on level of injury
Trunk, pelvic organs, and legs maybe involved
Term used in referring to cauda equina and conus medullaris injuries
Does not involve lumbosacral plexus lesions or peripheral nerves outside the canal
Complete Transverse Syndrome
Below level of injury there is loss of all motor and sensory nerve transmissions
Causes of complete paraplegia or quadraplegia
Complete severence of spinal cord
Complete breakage of nerve fibers by stretching of the cord, coverings may still be intact with normal appearance
Complete ischemia of the cord, interruption of the total blood supply
Incomplete Syndromes
Central Cord
Anterior Cord
Brown-Sequard
Conus and Cauda Equina Injuries
Central Cord Syndrome Cause
Damage to central portion of cervical cord
Corticospinal tract fibres are organized with arms most central, trunk immediately, and legs laterally
Brown - Sequard Syndrome Cause
Damage to one side of the cord only
Conus and Cauda Equina Results
Loss of motor function
Sensory function not markedly impaired
Extremely variable pattern with asymmetrical involvement
Roots have some recovery potential, causing outlook to be favorable
Lower motor neuron (flaccid) invovlement of bowels, bladder and sexual function because those reflexes are controlled within the conus
Central Cord Syndrome Results
Fibres located most centrally are damaged with those more laterally spared
Arms affected but legs may not be
Some distal nerve transmission is intact
Anterior Cord Syndrome Results
Loss of function below injury level to cord portion responsible for voluntary motor pathways and major sensory tract
Sparing of posterior column due to alternate blood supply
Position, vibration, and touch sense are preserved
Conus and Cauda Equina Injuries Cause
Damage to the conus medullaris or spinal nerves forming the cauda equina
Anterior Cord Syndrome Cause
Usually caused by damage due to infarction from main artery
Resultant blood loss to anterior 2/3 of the cord
Posterior cord is unaffected
Factors in determining appropriate management of cervical injury
Type of fracture and/or associated dislocation
Stability
Alignment
Cervical Fracture or Fracture/Dislocation requires reduction
Patient put in traction with weights applied to CB tongs or a halo ring
Generally 20-30 lbs are used to reduce and maintain the alignment of a fracture
Up to 120 lbs can be used to reduce locked facet joints
Cervical orthosis provides 3 primary functions
- Motion restriction to protect or prevent pain
- Motion restriction to protect spinal instability pre-post surgery
- Emergency protection - immediately following trauma
Spinal mobility
Cervical > Lumbar > Thoracic
Thoracic spine possess greater flexion than extension
Lateral flexion increases in the caudal direction, while axial rotation decreases
Brown- Sequard Results
Ipsilateral loss of function below injury level, ipsilateral motor paralysis
Loss of pain and temperature sensation on the contralateral side of the body
Biomechanical Principles of Orthotic Design
Balance horizontal forces
Fluid compression
Distraction
Construction of cage around patient
Placement of irritant = kinesthetic reminder
Skeletal fixation
Increase intra-abdominal pressure to decrease vertebral load
Restriction of motion:
Damage to posterior element, instability increases with flexion
Damage to the anterior element, instability increases with extension
Surgical Management
Posterior Wiring
Anterior decompression
Contoured anterior spinal plate
Neutral head position
Alignment of patient head with respect to the body is crucial for device success
Know neutral head position in the coronal and sagittal plane
Be aware that this position may vary with each patient according to pain and comfort
