spine Flashcards
Describe a hangman’s fracture
AKA traumatic spondylolysis of C2.
An unstable fracture caused by extreme hyperextension. Bilateral #s through pedicles of C2. Although unstable, SCI can be minimal b/c spinal canal has greatest diameter at this level.
Describe extension teardrop #
Stable in flexion. Unstable in extension
fracture in lower cervical vertebrae. Caused by extreme hyperextension with causes anterior longitudinal ligament to avulse anteriorinferior corner of body. Buckling of ligamentum flaavum into the canal can cause central cord lesion
What spinal cord injury is associated with a burst fracture
anterior cord syndrome
What differentiates a wedge fracture from a burst fracture
A burst fracture will have >40% compression of anterior vertebral body on imaging and has a characteristic vertical fracture on anterior films
Describe Jefferson fracture
Extremely unstable fracture through ring of C1. Lateral masses >7mm offset from pillars of C2. Associated with prevertebral hemorrhage and widened prevertebral space
When is wedge fractures (usually considered stable) potentially unstable?
- Severe wedging – Loss of >50% height
- Multiple adjacent wedge fractures
Classify odontoid fractures.
- I: Odontoid process above transverse ligament
- II: Base of odontoin process
III: Through body of C2
List mechanisms of primary cord damage.
- Transection
- Compression (hypertrophied or arthritically enlarged bony or ligamnetous elements)
- Primary vascular damage
o Compression by hematoma
o Ischemia due to compression of vertebral arteries or artery of Adamkiewitcz
List pre-existing chronic conditions which predispose to cervical injury.
Down syndrome – atlanto-ocipital dislocation
(normal is 15y.o.
AAOD= anterior atlanto-odontoid distance
Rheumatoid arthritis – C2 transverse ligament rupture
Ankylosing spondylitis – Spine becomes like one long bone
Describe the spinal motor exam for upper and lower extremities: (Table 43-2).
C4 Spontaneous breathing C5 Shrugging of shoulders C6 Elbow flexion C7 Elbow extension C8-T1 Finger flexion T1-T12 Intercostal and abdomen muscles (complete localization by sensory exam) L1-L2 Hip flexion L3 Knee extension + Hip adduction L4 Knee extension + Hip adduction L5 Ankle dorsiflexion + Hip abduction S1-S2 Ankle plantar flexion S2-S4 Rectal sphincter tone
Describe the spinal reflexes and their corresponding nerve roots (Table 43-3)
C6 Biceps
C7 Triceps
L4 Patellar
S1 Achilles
What is spinal shock? What is its significance?
- Concussive injury to the spinal cord that causes total neurologic dysfunction distal to the site of injury
- Mimics complete cord injury
- Flaccid paralysis, areflexia
- Prognosis cannot be accurately determined until spinal shock has ended (usually less then 24 hours, occasionally longer)
In a patient with flacid paralysis after a spinal cord injury, what is the significance of the bubocavernosis reflex?
- Intact bulbocavernosus reflex (contraction of the rectal spincter with squeezing the glands penis or clitorus or pulling on the foley catheter) indicates that spinal shock is not or is no longer present
o Absent – spinal shock likely – cannot determine prognosis (differentiate complete from partial injury)
Bulbocavernosus Present – spinal shock not contributing – poor prognosis for recovery
What are the three common incomplete cord lesions?
- Central cord
- Brown-Sequard
- Anterior cord
Describe the mechanism and clinical picture of each of the incomplete cord syndromes.
Central cord: weakness UE greater than LE
Brown-Sequard lesion: cord hemisection with ipsilateral loss of motor, position, vibration and contralateral loss of pain and temperature
Anterior cord: paralysis and hypoalgesia with preservation of posterior column (position/vibration)
List the clinical characteristics of acute cauda equine syndrome.
- Unilateral or bilateral leg pain
- Bowel or bladder dysfunction
- Perianal anesthesia
- Diminished rectal tone
- Lower extremity weakness
What causes “dejeune onion skin” pattern of analgesia?
- Damage to the spinal trigeminal tract (of the trigeminal nerve)
List the 5 nexus criteria for identifying patient at “extremely low probability of spinal injury.”
- No Posterior midline tenderness
- No focal neuro DEFICIT
- Not DECREASED LOC
- No Intoxication (DRUNK)
- No painful, DISTRACTING injuries
Validation:
- n >34000
- SN 99.6%, SP 12.9%, NPV 99.8%
- Predicted high radiography rates at 87%
List the components of the Canadian C-spine Rule for identifying “clinically important” cervical spine injuries?
Inclusion Ø Alert, stable trauma patients Exclusion: Ø Non-trauma Ø GCS65 b. Fall from >1m c. Axial loading d. High speed MVC (>100km/hr) e. Rollover f. Ejection g. Motorized recreational vehicle h. Bicycle i. parasthesia 2. Any Low risk present that could safely assess ROM? a. Simple rear end b. Sitting in ED c. Ambulatory at any time d. Delayed onset neck pain e. No midline tenderness 3. Can patient rotate head 45 degrees to left and right? If low risk features and no high risk features, can ROM neck and clear C/S Validation: - n = 8924 - SN 99.4, SP 45.1, NPV 100% - Predicted radiography rates at 58%
How is the posterior cervical line (Swischuk) used in children to differentiate pseudosubluxation from injury?
If the base of the spinous process of C2 lies >2mm anterior or posterior to the posterior cervical line (bases of spinous process of C1-C3), an injury should be suspected
How wide is a wide predental space?
- Adults 3mm
Children 5mm
