Spinal Trauma

Anatomy

Anterior column: Ant long lig, ant part annular lig Ant ½ vertebraeMiddle column: Post long lig, post part annular lig Post ½ vertebraePosterior column: Interspinous lig, lig flavum IV facet joint, pedicles, laminae, spinous processes, neural arch

Epidemiology

Unstable when: 2/3 columns affected>3mm displacement of vertebral bodyAngle >11° between vertebraeAnterior height <⅔ posterior height (>25% height of affected vertebral body)Fanning of interspinous distance

Post lig involvement suggested by: avulsion # tip spinous process, wide separation of vertebral spines, facet joint fracture, neural arch fracture, shift of 1 vertebrae on another, shearing fracture of vertebral body. If present = ?unstable, ?neural involvementMovements: C3-7 all directions C1-2 rotation Atlanto-occipital joint flexion/extensionSpinal cord: spinal cord ends at L1-2; lumbar and sacral segments of spinal cord lie between T10-L1 (T12 vertebrae = L1 spinal cord)Spinothalamic Crosses at spinal cord; cervical sensation medial, sacral sensation at periphery Anterior: touch and pressure Lateral: pain and temp Dorsal Crosses at medulla; sacral sensation medial, cervical peripheral Touch, pressure, vibration, proprioceptionCorticospinal Anterior crosses at spinal cord, lateral crosses at medulla Anterior: axial and proximal muscles, posture, gross motor, 20% Lateral: distal muscles, fine motor, 80%

C spine: Male:female 4:1; risk factor from MVAs are HI (most important), ejection, roll over, no seat belt, facial burns, extensive car damage, death of occupant; C2 most common fracture (25%); C5-6 / 6-7 most common dislocationT/L spine: T/L junction most at risk; 65% fractures between T12 and L2, 90% between T11 and L4; 95% are vertical / oblique, 5% horizontal; 20% with fractures have 2nd fracture; 50% have other injury

Paediatrics Lower incidence; more upper C spine and atlanto-occipital (large head, lax ligaments, horizontal plane of facet joints); dens fuses at 6-8yrs; treat children >8yrs as would adults; use CT sparingly

NEXUS Criteria

Not applicable to infants; 99% sensitivity for any injury, 99.6% sensitivity for significant injury, 13% specificity; results in 12% C spine imagingNo XR if blunt injury and: no FND No ETOH No Xtra (distracting) injury No Unconscious (ie. Normal LOC) No Spinal tenderness of neck

Assess rotation 45° only XR if can’t do

C1

15-20% associated with

C2 injury

25% associated with lower C spine injury

Jefferson fracture: vertical compression injury; blowout fracture anterior and posterior arch, disrupts transverse ligament; lateral masses C1 driven laterally; wide pre-dental space, but post spinal line may be OK; displacement of lateral masses >2mm or unilateral displacement; unstable; 50% survive without deficit; ⅓ associated with C2 fracture; ½ associated with other C spine fracture

Fracture posterior arch atlas: extension injury; maybe unstable; treat in collar / traction for 6/52Atlanto-occipital dislocation: flexion injury; fatal; unstableAnterior atlanto-axial dislocation: flexion injury; rupture of transverse ligament of dens; often fatal; unstablePosterior atlanto-axial dislocation: extension injury; unstableRotatory atlanto-axial dislocation: rotational injury; torticollis; may be associated with anterior displacement; unstable

C2

Most commonly fractured vertebrae

Usually associated with

C1 injury

Canadian C Spine Rule

Incorporates MOI and examination findings; for alert, stable patients; sensitivity 100%, specificity 43% for clinically important injury; results in 15% C spine imaging; compares favourably with NEXUSHigh risk therefore do XR if: >65yrs / extremity paraesthesia / fall >1m / fall >5 stairs / axial load to head / high speed MVA, roll over, ejection / bike collision / motorised recreational vehicle Low risk therefore no XR needed if: walking after injury / sitting in ED / simple rear shunt / delayed onset neck pain / no midline tenderness

If low risk criteria fulfilled, assess rotation 45° only XR if can’t do If low risk criteria not fulfilled, do XR

Investigation

C spine XR: anterior intervertebral line, posterior intervertebral line, spinolaminar line, interspinous line (displacement of 2 lines suggests unstable injury; <1mm anterior subluxation (<3mm in children) may be normal); predental space (<3mm adult, <5mm children); vertebral body height (posterior height should be at least 3mm more than anterior height); soft tissue swelling (present in 60% anterior fracture, 30% posterior fracture, 15% patients with no injury – due to ETT, pooled pharyngeal secretions, child) Penning’s criteria: C1 <10mm / C2 <7mm / C6 <22mm (15mm in children) (or <width vertebral body) Sensitivity 95% if adequate films (70-85% with lateral shoot-through in trauma room); 0.2% risk of missing unstable injury; inadequate views in up to 35% Flexion/extension views not recommended, risk of neurological injury, false negative from spasm, no clinically validated criteria for interpretation, do MRI insteadC spine CT: Indications: any fracture/?fracture on XR (25% will have 2nd fracture, 35% will not have been visible on XR), head CT, high index suspicion despite normal XR Sensitvity >95% for fracture / dislocation; may miss ligamentous injury at C1-2; if altered LOC, no FND, normal CT false neg rate 0.1%C spine MRI: better than CT for ligaments, discs, spinal cord; Sensitivity 100% for cord injury, 55% for fracture, 80% for dislocations; in spinal cord, hypoattenuation = haemorrhage, hyperattenuation = oedema / transection; investigation of choice if neuro symptomsL/T spine XR: widened mediastinum; displacement of L paraspinal line; pleural cap; interpedicular distances should gradually increase from L-5; lack of concavity of post vertebral body cortex (?burst fracture); sensitivity 75%L/T spine CT: sensitivity 95%

Hangman’s fracture: extension +/- distraction injury; bilateral fracture of pedicles of axis (through pars interarticularis) anterior movement of C2 on 3 of >2mm, avulsion of ant-inf corner of C2 associated with rupture of ant long lig; prevertebral soft tissue swelling; unstable; cord injury rare; causes Horner’s syndrome (ipsilateral constricted pupil due to damage of sympathetic trunk); treat with external immobilisation

C2(cntd)

Dens Fracture: flexion injury; 10-15%; complicated by soft tissue swelling I = 5-8% = tip, above transverse ligament II = 55-70% = junction of body and dens; unstable; needs OT if displaced >6mm III = 30-35% = through body of dens; unstable but good prognosis

Extension teardrop fracture: usually involves axis; extension injury; unstable; causes central cord syndromeOs odonotoideum: failure of fusion of tip to body of dens (ossification centre should appear at 2yrs, fuse by 12yrs); unstable, requires post fusionC2-3 pseudosubluxation: common in infants and children (40% <8yrs) – will disrupt posterior interspinous line but spinolaminar line conserved, will cause pre-dental space in children; less commonly occurs at C3-4, 4-5 levels

C7Clay shoveller’s fracture: flexion injury; avulsion / direct blow to lower spinous processes; ghost sign on AP view (displaced fractured spinous process); stable; cervical collar 2-3/52

Anterior Teardrop Fracture

Flexion injuryWedge-shaped antero-inferior fractureLigamentous (anterior longitudinal ligament) and neurological involvement common due to retropulsion of fragmentsUnstable

Anterior Wedge /

Compression Fracture

C spine: Flexion injury; Stable; cervical collar 6/52T/L spine: major; flexion / axial load; most common at T12-L2; middle and posterior column intact; may be associated with ant-sup marginal shearing #; neural injury rare (more common if lateral wedging and nerve root involvement; if post wedging present, suggests more violence, ?burst fracture and ?spinal cord involvement); stable usually; unstable if anterior margin reduced >50% and posterior ligament injured; symptomatic treatment

Flexion/distraction injury, seatbelt injuyry, distraction injury occurs as pivot pushed more anteriorly, around anterior abdominal wall; major; failure of posterior column: complete disruption of spinous process, laminae, transverse process, pedicles, vertebral bodies; oblique / horizontal splitting of spinous process and neural arch, pushing post-sup aspect of vertebral body into intervertebral disc; widened interpedicular distance seen; suggested by vacant appearance of vertebral body on AP film, discontinuity of cortex of pedicles / spinous processes on AP failure of posterior and middle columns; ligamentous involvement; unstable; 65% have intestinal / mesenteric injury

Chance Fracture

POSTERIOR INVOLVEMENT

Horizontal Fissure

FractureSimilar to Chance fracture, but fracture line extends horizontally through vertebral body to anterior aspect

Smith Fracture Fracture through superior articular processes, arch and sup-post vertebral body, but spares posterior spinous processes; posterior ligaments disrupted

Burst Fracture

C spine: Vertical compression injury; comminuted but ligaments intact; fracture fragments may still injure cord; stable unless severe (>15-20°); traction 6/52T/L spine: major; vertical compression injury; loss of vertebral height anteriorly and posteriorly pedicles widened on AP; fracture fragments may injure cord; failure of anterior and middle columns; unstable

Transverse Process Fracture

Associated with renal / ureteric / splenic / hepatic / pancreatic injury, adrenal haematoma, diaphragmatic hernia, pelvic fracture; L3 most common (30%)

Translational Injury Shear forces; AP/PA trauma; affects neural canal

Subluxation Flexion injury; loss of normal cervical lordosis, fnaning of interspinous distance; only anterior intervertebral ligament intact; unstable; requires reduction / fusion

Rotational injury; disruption (>2mm) of spinolaminar line and spinous processes on AP / lateral film; wide interspinous distances; widening of disc space; subluxation <½ vertebral body width of vertebra above over vertebra below; angulation of spine by >11° on AP view; better view available on oblique films; unstable if associated facet fracture; treat by reduction

Unilateral Facet Joint Dislocation

Flexion injury; Disruption of anterior ligament and annulus of disc; bow tie / bat wing appearance of locked facets; subluxation >½ vertebral body width; unstable; require reduction / fusion

Unilateral Facet Joint Dislocation

C Spine Immobilisation

Indication: recommended if for XR; no evidence of efficacy in prevention of spinal cord injury in conscious patients (may worsen outcome by uncontrolled reduction); optimal position with 2cm occiput elevationMethod: Use C spine collar, sandbags + tape (better than collar), headblock and spinal board, strapping, Vac PacComplications: ICP, access to neck, discomfort, prompts unnecessary investigation, patient anxiety, cutaneous pressure ulceration (especially if prolonged use), requirement for log rolling, aspiration, DVT, may worsen neurological injury (if displaced fracture, pre-existing cervical deformity), masks other injuries, pulmonary function

Cord Injury

Usually associated with bony / ligamentous injury (SCIWORA rare, more in children, more in C spine); most common in C5-T1, mid-thoracic, L1-T12, close to bony fusion; “level” refers to last unaffected level; “complete” if ongoing symptoms after reflexes return (implied incomplete if sacral sparing); paralysis flaccid and areflexia in spinal cord injuryMOI: direct trauma, 2Y oedema, excitatory neurotransmitter release, epidural haematoma, vascular injury, delayed apoptosis of oligodendrocytes

Central Cord Syndrome

Anterior Cord Syndrome

Posterior Column Syndrome

Motor Sensory Autonomic

Brown-Sequard Lesion

Neurogenic Shock

Spinal Shock

Autonomic Dysreflexia

Bilat arm > leg weak Bilat prox > distal weak

Reflexes variable

Bilateral leg > arm weakness

No motor involvement

Ipsilateral weaknessReflexes variable

Quadriplegia / high paraplegia

Loss of voluntary movement and reflexes

As per old lesion

Bilat arm > leg numbBilat prox > distal numb

Bilat pain, temp, coarse touch (some dorsal column

sensation still OK)

Bilat vibration, light touch + proprioception

Ipsilat vibration, light touch and proprioception; contralat pain and temp

?

Loss of sensation

As per old lesion

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-

-

No sphincter involvement

HR/BP; vasoD; poikilothermia; no sweating; erection; paralytic ileus; sphincter paralysis; flaccid bladder

paralysis

autonomic reflexes below level of lesion

Impaired total body SNS, pelvic PNS; HR; BP; headache;

sweating; erection; flushing above lesion; cold; piloerection below

lesion; bowel/bladder contraction; mydriasis; headache

Hyperextension injury in elderly; 50% good

recovery

Flexion / vertical compression; 10-15% full

recovery

Hyperextension / penetrating inj from back

Penetrating injury / unilateral facet joint inj;

mod outcome

Temporary cessation of SC neuro function

Complete injury above T1-4; resolves in 48hrs

Lasts few hrs - several wks

Any lesion at/above T6; trigger eg. Bladder distension, p sore

Treat: elevate head, 10mg SL nifedipine,

remove cause

Cord Injury

Treatment:A: insert NGT (high risk of aspiration); consider ETT; have atropine available as exaggerated vagal response to instrumentation; C spine immobilisation; pre-vertebral haematoma can obstruction; RSI best if urgent, fibreoptic if notB: paradoxical breathing; assess vital capacity; O2 to prevent 2Y injury (as in HI)C: assess GCS, UO, CVP; early insertion of IDC; suspect hypovolaemia until proven otherwise if BP bolus IVF; may require inotrope / chronotrope; neurogenic shock makes it hard to assess degree of bleedingD: look for Horner’s if injury at/above T4; PR; anal and bulbocavernosus reflex; analgesia; attention to temperature; place IDC early to avoid bladder overdistensionE: care for pressure areas

Steroids: indicated if <8hrs / recommended by spinal unit; 30mg/kg IV methylpred over 15mins 5.4mg/kg VI infusion over 23hrs; contraindicated if heavily contaminated wounds, bowel perforation, sepsis, diabetesPrognosis: 50% good recovery if preservation of S4-5 sensation at 3-7/7 (10-15% without); areas of sparing in dermatome gives 50% chance recovery in that myotome; incr age, worse prognosis