Basics of Spinal Trauma Flashcards
What is a myotome?
Group of muscles that a single spinal nerve root innervates. Nerve levels are associated with certain movements as seen in image attached
What is a dermatome?
An area of skin supplied by a single nerve root
In terms of anatomical columns of the spine, what constitutes the anterior column of the spine?
- Anterior longitudinal ligament
- Anterior annulus
- Anterior 2/3rd’s vertebral body
In terms of anatomical columns of the spine, what constitutes the middle column of the spine?
- Posterior 1/3 of the vertebral body
- Posterior annulus
- Posterior longitudinal ligament
In terms of anatomical columns of the spine, what constitutes the posterior column of the spine?
Everything posterior to the PLL
- Pedicles
- Facet joints and articular processes
- Ligamentum flavum
- Neural arch and interconnecting ligaments
- Spinous Processes
What system is most commonly used to classify thoracolumbar spinal fractures?
McAfee Classification system
What is a wedge compression fracture?
Isolated anterior column compresson
What is the following fracture?
Wedge compression fracture
What is a stable burst fracture?
Anterior and middle column compression, but posterior column is normal
What type of fracture is this?
Burst Fracture - stable
What is an unstable burst fracture?
Anterior and middle column compression, with disrupted posterior column
What is the mechanism of injury of a burst fracture?
High-energy compressive injury (axial loading) - IV disc is rammed into vertebral body
Typically fall from height or motor vehicle accident
What is the mechanism of injury of a flexion distraction fracture?
Axis of flexion: posterior to anterior longitudinal ligament
What is a flexion-distraction fracture?
- Compressive failure of the anterior column while the middle and posterior columns fail in tension
- Tensile failure of the middle column results in tear or attenuation of the posterior longitudinal ligament
- Subluxation, dislocation or fracture of the facets can occur
- Most varieties of this injury are potentially unstable because the ligamentum flavum, interspinous ligament, and supraspinous ligament usually are torn
What type of fracture is the following?
Burst fracture - Unstable
What is a Chance fracture?
- Flexion-distraction type injuries of the spine that extend to involve all three spinal columns
- The anterior and middle columns fail in compression, and the posterior column fails in distraction
- Extend all the way through the spinal column: from posterior to anterior through the spinous process, pedicles, and vertebral body, respectively
- Unstable injuries and have a high association with intra-abdominal injuries.
What type of fracture is the following?
Flexion distraction injury
What type of fracture is the following?
Chance fracture
What are translational spinal fractures?
- All three columns have failed in shear
- Displacement in the transverse plane with alignment disruption of the spinal canal
What is the mechanism of injury of a chance fracture?
Flexion about an axis anterior to the anterior longitudinal ligament - e.g. seatbelt in a car crash
What type of fracture is the following?
Translational fracture
What types of thoracolumbar injuries fall under the category of tranlational fractures?
Rotational fracture-dislocations and pure dislocations
What criteria does a fracture have to meet to be classified as unstable?
Any one of:
- > 30o kyphosis
- > 50 % loss of vertebral height
- Both columns involved
- Pedicles splayed
What can cause spinal injury?
- Spinal fractures
- Motor vehicle accidents
- Falls from height
- Sports injuries
- Violence
- Penetrating injuries – gunshots, stabbings
What is spasticity?
Resistance to the passice movement of a limb that is maximal at the beginning of a movement and gives way as more pressure is applied (also known as clasp - knife rigidity)
Symptom of damage to the pyramidal tract in the brain or spinal cord
Usually accompanied by weakness in the affected limb
What are the general clinical features of cervical, thoracic, lumbar and sacral injury?
- Pain
- Flaccidity, paralysis, numbness
- Paraesthesia, paresis, weakness
- Priapism, incontinence
- Hypotension
- Bradycardia
- Vasodilatation
What is spinal shock?
Loss of sensation accompanied by motor paralysis with initial loss, but gradual recovery, of reflexes, following a spinal cord injury (SCI) – most often a complete transection
Reflexes below the level of injury are depressed (hyporeflexia) or absent (areflexia), while those above the level of the injury remain unaffected
If the injury is to recover ⇒ some distal sensation and bulbo-cavernosus reflex should have occurred within 24 hours (described as an incomplete injury)
What is neurogenic shock?
Trauma causes a sudden loss of background sympathetic stimulation to the blood vessels⇒ vasodilation resulting in a sudden decrease in blood pressure (secondary to a decrease in peripheral vascular resistance)
Can have slowed heart rate due to unopposed vagal activity
THIS IS LIFE THREATENING
What symptoms would indicate neurogenic shock?
- Paralysis
- Hypotension
- Bradycardia
What are the initial stages of management in the treatment of a spinal injury?
- ATLS - ABCDE
- Immediate life-threatening injuries - e.g. haemorrhage
- Immobilise spine
- Other injuries?
- Mechanism of injury
What grading system is used to assess the severity of a spinal cord injury?
Frankel grading system
What does frankel grade A indicate?
Complete paralysis
What does frankel grade B indicate?
Sensory function only below level of injury
What does frankel grade C indicate?
Incokmplete motor function below the level of injury
What does frankel grade C indicate?
Incokmplete motor function below the level of injury
What does frankel grade D indicate?
Fair to good motor function below the level of the injury
What does frankel grade E indicate?
Normal function
What is the bulbocavernous reflex?
Polysynaptic reflex that is useful in testing for spinal shock and gaining information about the state of spinal cord injuries (SCI)
Mediated by spinal level S2-S4
How would you test the bulbocavernous reflex?
Monitor internal/external anal sphincter contraction in response to squeezing the glans penis or clitoris, or tugging on an indwelling Foley catheter
What would an abscent bulbocavernous reflex potentially indicate?
- Spinal shock
- IF SPINAL SHOCK NOT SUSPECTED - Injury to conus medullaris or sacral nerve roots
If the bulbocavernous reflex had returned after being absent, but motor and sensory function had not, what would this indicate?
Complete spinal cord injury
