> Table of Contents > Cervical Hyperextension Injuries
Cervical Hyperextension Injuries
Shane L. Larson, MD
Derek G. Zickgraf, DO
image BASICS
DESCRIPTION
  • Class of neck injuries typically seen in rapid, forceful extension of the cervical spine (head extends posteriorly)
  • Usually from motor vehicle accidents (MVA— whiplash), falls, or sports-related injuries (1)
  • May involve
    • Injury to vertebral and paravertebral structures: fractures, dislocations, ligamentous tears, and disc disruption/subluxation
    • Spinal cord injury (SCI): traumatic central cord syndrome (CCS) secondary to cord compression or vascular insult, SCI without radiologic abnormality (see “SCIWORA”)
    • Blunt cerebrovascular injury (BCVI): vertebral artery or carotid artery dissection
    • Soft tissue injury: cervical strain/sprain (i.e., whiplash), cervical stingers (see “Brachial Plexopathy”)
EPIDEMIOLOGY
  • Predominant age: Trauma and sports injuries are more common in young adults (average age 29.4 years); however, CCS mostly seen in older population (average age is 53 years)
  • Predominant sex: male > female (1)
Incidence
In the United States
  • Cervical fractures: 2 to 5/100 blunt trauma patients
  • CCS: 3.6/100,000 people/year
  • BCVI: estimated 1/1,000 of hospitalized trauma patients; incidence increased with cervical spine or thoracic injury
  • Cervical strain: 3 to 4/1,000 people/year
  • Whiplash is the most common injury in MVAs and accounts for 28% of all ED visits for MVAs (2).
  • Incidence of whiplash is 70 to 328/100,000 with rates peaking in 20- to 24-year-old females (3).
  • 5% of trauma patients have spinal fractures and 20% of those have SCI.
  • The incidence of traumatic SCI ranges from 2.3 to 83 cases per million population per year (2).
ETIOLOGY AND PATHOPHYSIOLOGY
Blunt trauma due to MVAs, sports injuries, falls, and assaults
RISK FACTORS
  • Whiplash, initial injury: no seat belt use, female gender (3)[C]
  • Chronic pain and/or disability: litigation, previous neck pain or injury, low education level (4,5)[C]
  • Fractures: osteoporosis, conditions predisposing to spinal rigidity, such as ankylosing spondylitis or other spondyloarthropathies
  • CCS: Preexisting spinal stenosis is present in >50% of cases, which may be
    • Acquired: prior trauma, spondylosis
    • Congenital: Klippel-Feil syndrome (congenital fusion of any 2 cervical vertebra)
GENERAL PREVENTION
Seat belts, use of proper safety equipment, rule changes, and technique-coaching emphasis in sports activities can potentially prevent or minimize injury.
COMMONLY ASSOCIATED CONDITIONS
Closed head injuries, whiplash-associated disorders (WAD), SCI, soft-tissue trauma
image DIAGNOSIS
PHYSICAL EXAM
  • External signs of trauma on the head and neck such as abrasions, lacerations, or contusions are clues to mechanism and associated injuries.
  • Presence, severity, and location of neck tenderness often helps localize involved structure(s):
    • Posterior midline, bony tenderness concerning for fracture
    • Paraspinal or lateral soft tissue tenderness suggests muscular/ligamentous injury.
    • Anterior tenderness concerning for vascular injury
  • Carotid bruit suggests carotid dissection.
  • Neurologic exam: Paresthesias, weakness suggests SCI or stroke secondary to BCVI:
    • CCS often presents as
      • Distal > proximal symptom distribution, upper extremity > lower extremity
      • Extremity weakness/paralysis predominates.
      • Variable sensory changes below level of lesion (including paresthesias and dysesthesia)
      • Bladder/bowel incontinence may occur.
DIFFERENTIAL DIAGNOSIS
  • Acute or chronic disc pathology (including herniation or internal disruption)
  • Osteoarthritis
  • Cervical radiculopathy
  • For CCS
    • Bell cruciate palsy
    • Bilateral brachial plexus injuries
    • Carotid or vertebral artery dissection
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
  • Low-risk patients can be cleared clinically (without imaging) using either the Canadian C-spine Rule (CCR) or the National Emergency X-Ray Utilization Study (NEXUS) criteria (6)[B]:
    • CCR: Clinically clear a stable, adult patient with no history of cervical spine disease/surgery if all of the following conditions are met:
      • Glasgow Coma Scale (GCS) ≥15
      • Nonintoxicated patients without a distracting injury
      • No dangerous mechanism or extremity paresthesias
      • Age <65 years
      • At least 1 “low-risk factor” (i.e., simple rear-end MVA, ambulation at the accident scene, no midline cervical tenderness, delayed onset of neck pain, or sitting position at the time of exam)
    • NEXUS: Clinically clear if all of the following are met:
      • No alteration of mental status or intoxication
      • No focal/neurologic deficits
      • No distracting injury
      • No posterior, midline C-spine tenderness
    • Reported sensitivity/specificity: CCR (99.4%/45.1%), NEXUS (90.7%/36.8%)
  • In patients with high-risk mechanism or any concerning historical/physical exam elements, imaging should strongly be considered. Choose from the following options based on the suspected injury and level of clinical suspicion:
    • Plain radiographs: recommended by some in patients who cannot be cleared clinically but still are in low-suspicion category: sensitivity for C-spine injury 39%:
      • Dynamic: flexion/extension; only if asymptomatic and no neurologic deficits or mental impairment, poor identification of ligamentous injury, limited diagnostic value (7)[A]
    • CT: axial CT from occiput to T1 with coronal and sagittal reconstructions; has replaced plain radiography as the test of choice for cases with moderate to high clinical suspicion of C-spine injury, given high sensitivity (90-100%)
    • MRI: test of choice in CCS with direct visualization of traumatic cord lesions (edema or hematomyelia), soft tissue compressing cord, and/or stenosis of canal. Detects ligamentous injury and abnormalities of intervertebral discs and soft tissues. MRI is poor with fractures due to false-positive results from nonspecific findings.
    • CT angiography: visualization of cervical and cerebral vascular structures to detect BCVI, with reported sensitivity approaching 100% when a ≥16-slice CT scanner is used. MR angiography is an alternative modality, although accessibility and reported sensitivities of 47-50% limit its use settings.
Test Interpretation
  • Vertebral fractures: See “General Measures.”
  • CCS: currently thought to be due to axonal disruption within the white matter of the lateral column, particularly the corticospinal tracts
  • BCVI: intimal disruption, leading to thrombosis and embolization
  • Acute cervical strain/sprain: Models based on animal, cadaver, and postmortem studies show myofascial tearing, edema, and inflammation.
Geriatric Considerations
  • Degenerative changes of the C-spine may be confused with acute traumatic change, and osteopenia may limit fracture visualization on x-ray—CT more accurately makes this differentiation.
  • Degenerative disease and osteopenia increases the risk of upper cervical spine injuries despite low-velocity trauma (3)[B].
Pediatric Considerations
Consider SCI without radiographic abnormality (SCIWORA): high incidence at <9 years and accounts for up to 50% of all pediatric cervical spine injuries. MRI may help detect the injury.
image TREATMENT
GENERAL MEASURES
  • Whiplash, WAD
    • Limited or no benefit to cervical collar; if needed, use for <72 hours (8)[C]
    • No advantage to engaging early multiprofessional intervention (e.g., pain management and psychology) (9)[C]
    • No evidence of different outcomes with physical therapy versus passive (immobilization, rest) treatment. Advance activity levels as tolerated.
    • Lack of clear effective treatments in current medical literature in absence of fracture (4)[B]
  • P.179

  • Fractures
    • Stability determined by imaging; decompression, and stabilization are indicated in
      • Incomplete SCIs with spinal canal compromise
      • Clinical deterioration or failure to improve despite conservative management
    • Hangman fracture: traumatic spondylolisthesis of C2 with bilateral fractures through C2 pedicles, often with anterior subluxation of C2 over C3; can be unstable:
      • Managed with halo vest immobilization for 12 weeks until flexion/extension films normalize
    • Odontoid fractures: treated according to type:
      • I: through apex; usually stable; external immobilization with a cervical collar (less often halo vest) for up to 12 weeks
      • II: most common, at base of dens, usually unstable; nonunion rates of up to 67% with halo immobilization alone, especially with dens displacement >6 mm or age >50 years
      • III: through C2 body, usually stable; immobilization in halo or cervical collar for 12-20 weeks
    • Hyperextension teardrop fractures
      • If stable, rigid collar or cervicothoracic brace for 8 to 14 weeks
      • If unstable, halo brace for up to 3 months
  • CCS: neck immobilization with cervical collar, physical therapy/occupational therapy (PT/OT)
  • Cervical strain: No difference in outcomes with active (PT) versus passive (immobilization, rest) treatment; may use soft cervical collar for 10 days for symptomatic relief, then mobilize and increase activity as tolerated.
  • Lack of clear effective treatments in current medical literature in absence of fracture (4)[B]
MEDICATION
  • Fractures: pain control as needed with analgesics
  • CCS: Within 8 hours of injury, consider methylprednisolone 30 mg/kg IV over 15 minutes, then continuous infusion 5.4 mg/kg/hr IV for 23 hours. Further improvement in motor function recovery may be seen if infusion is continued for 48 hours, especially if initial bolus administration is delayed by 3 to 8 hours after injury (10)[A].
  • BCVI: Anticoagulation with IV heparin, followed by warfarin therapy for 3 to 6 months, then long-term antiplatelet therapy is a common practice. However, an antiplatelet agent is used as the sole initial therapy in patients with contraindications to anticoagulation. To date, no randomized controlled trials compare the efficacy of antiplatelet versus anticoagulant therapy, so evidence-based recommendations are unavailable.
  • Cervical strain: muscle relaxants, acetaminophen/NSAIDs ± opiate analgesics are commonly used.
ISSUES FOR REFERRAL
  • When cervical spine injury is suspected, the patient should be immobilized and sent to the ED.
  • Emergent consultation from a spine surgeon for any concern for unstable fracture or SCI
SURGERY/OTHER PROCEDURES
  • Fractures
    • Hangman fracture: surgical fixation for excessive angulation or subluxation, disruption of intervertebral disc space, or failure to obtain alignment with external orthosis
    • Odontoid fractures
      • Type II: Early surgical stabilization is recommended in setting of age >50 years, dens displacement >5 mm, and specific fracture patterns.
      • Type III: Surgical intervention is often reserved for cases of nonunion/malunion after trial of external immobilization.
  • CCS: Surgical decompression/fixation is indicated in setting of unstable injury, herniated disc, or when neurologic function deteriorates.
  • BCVI: Surgical and/or angiographic intervention may be required if there is evidence of pseudoaneurysm, total occlusion, or transection of the vessel.
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
  • Varies by injury; clinical judgment, imaging findings, concomitant injuries, and need for operative intervention
  • Advanced Trauma Life Support protocol with backboard and collar
image ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
Patients with known injuries will often be followed with serial imaging under the care of a specialist.
PATIENT EDUCATION
For patient instruction on prevention: ThinkFirst Foundation: http://www.thinkfirst.org
PROGNOSIS
  • Presenting neurologic status is the most important.
  • Fractures
    • Hangman fracture: 93-100% fusion rate after 8 to 14 weeks external immobilization
    • Odontoid fracture, fusion rate by type: type I ˜100% with external immobilization alone; type II nonunion rates of up to 67% with halo immobilization alone, especially with dens displacement >6 mm or age >50 years; type III, 85% with external immobilization, 100% with surgical fixation
  • BCVI: With early diagnosis and initiation of antithrombotic therapy, patients may have fewer neurologic sequelae.
  • CCS
    • Spontaneous recovery of motor function in >50% of cases over several weeks, with younger patients more likely to regain function
    • Leg, bowel, and bladder functions return first, followed by upper extremities.
  • WAD: Prognostic factors for development of late whiplash syndrome (>6 months of symptoms affecting normal activity) include increased initial pain intensity, pain-related disability, and cold hyperalgesia (8).
REFERENCES
1. National Spinal Cord Injury Statistical Center. Spinal Cord Injury: Facts and Figures at a Glance. Birmingham, AL: National Spinal Cord Injury Statistical Center; 2015.
2. Oliver M, Inaba K, Tang A, et al. The changing epidemiology of spinal trauma: a 13-year review from a Level I trauma centre. Injury. 2012;43(8):1296-1300.
3. Quinlan KP, Annest JL, Myers B, et al. Neck strains and sprains among motor vehicle occupants— United States, 2000. Accid Anal Prev. 2004;36(1):21-27.
4. Wenzel HG, Mykletun A, Nilsen TI. Symptom profile of persons self-reporting whiplash: a Norwegian population-based study (HUNT 2). Eur Spine J. 2009;18(9):1363-1370.
5. Walton DM, Pretty J, MacDermid JC, et al. Risk factors for persistent problems following whiplash injury: results of a systematic review and meta-analysis. J Orthop Sports Phys Ther. 2009;39(5):334-350.
6. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349(26):2510-2518.
7. Sierink JC, van Lieshout WA, Beenen LF, et al. Systematic review of flexion/extension radiography of the cervical spine in trauma patients. Eur J Radiol. 2013;82(6):974-981.
8. Rasker JJ, Wolfe F. McLean et al.'s paper, “Incidence and predictors of neck and widespread pain after motor vehicle collision among U.S. litigants and nonlitigants”. Pain. 2014;155(7):1416.
9. Jull G, Kenardy J, Hendrikz J, et al. Management of acute whiplash: a randomized controlled trial of multidisciplinary stratified treatments. Pain. 2013;154(9):1798-1806.
10. Bracken MB. Steroids for acute spinal cord injury. Cochrane Database Syst Rev. 2012;(1):CD001046.
Additional Reading
  • Franz RW, Willette PA, Wood MJ, et al. A systematic review and meta-analysis of diagnostic screening criteria for blunt cerebrovascular injuries. J Am Coll Surg. 2012;214(3):313-327.
  • Liu BC, Ivers R, Norton R, et al. Helmets for preventing injury in motorcycle riders. Cochrane Database Syst Rev. 2008;(1):CD004333.
  • Shears E, Armitstead CP. Surgical versus conservative management for odontoid fractures. Cochrane Database Syst Rev. 2008;(4):CD005078.
  • Watanabe M, Sakai D, Yamamoto Y, et al. Upper cervical spine injuries: age-specific clinical features. J Orthop Sci. 2010;15(4):485-492.
See Also
Spine Injury: Cervical
Codes
ICD10
  • S13.4XXA Sprain of ligaments of cervical spine, initial encounter
  • S13.101A Dislocation of unspecified cervical vertebrae, init encntr
  • S14.109A Unsp injury at unsp level of cervical spinal cord, init
Clinical Pearls
  • Follow NEXUS or Canadian Cervical Spine rules on every patient with potential neck injury to determine imaging needs, but they do not supercede clinical judgment!
  • Inquire about preexisting cervical spine conditions, especially in the elderly, as they may increase risk of injury or change radiographic interpretation.
  • Suspect SCI until exam and imaging suggest otherwise.
  • Consider BCVI when neurologic deficits are inconsistent with level of known injury or significant mechanism exists.