​Kembara Xtra - Medicine - Cervical Hyperextension Injuries

​Kembara Xtra - Medicine - Cervical Hyperextension Injuries 
Introduction 

Class of neck injuries that are frequently caused by the cervical spine being extended quickly and forcefully
Whiplash injuries are frequently caused by motor vehicle accidents (MVAs).
Falls, assaults, or accidents sustained while playing sports are some additional factors.

- Damage to spinal and paravertebral structures, including disc disruption/subluxation, ligamentous rips, fractures, and dislocations.
- Traumatic central cord syndrome (CCS) brought on by cord compression or vascular insult; spinal cord injury without radiologic abnormality (SCIWORA);
- Blunt cerebrovascular injury (BCVI): carotid artery or vertebral artery dissection - Soft tissue damage: whiplash, cervical stingers, or cervical strain.

Incidence and prevalence in Epidemiology 
The average age of injury for SCI is 43 years, whereas the average age for CCS is 53 years.
Young individuals (average age 29 years) are more likely to sustain trauma and sports injuries.
The majority of new SCI patients (80%) are male (1).
Amount Occurring in the United States
Whiplash is the most common injury in MVAs and accounts for 28% of all ED visits for MVAs. The incidence of whiplash is 70 to 328/100,000, with rates highest in 20- to 24-year-old females. Cervical fractures: 2 to 5/100 blunt trauma patients; CCS: 4/100,000 people/year; BCVI: estimated 1/1,000 of hospitalized trauma patients; incidence increased with cervical spine or thoracic injury. The incidence of traumatic SCI is around 54 instances per million people per year, with 80% of cases falling below the C2 level (2).

Pathophysiology and Etiology 
Blunt trauma from motor vehicle accidents, slips and falls, sports injuries, and violence (most often gunshot wounds)

Whiplash risk factors include an initial injury, not wearing a seatbelt, and being a woman.

Litigation, prior neck discomfort or injury, female gender, reports of headache/low back pain at onset, poor education level, chronic pain and/or impairment
Fractures: osteoporosis, diseases such ankylosing spondylitis or other spondyloarthropathies that lead to spine stiffness.

>50% of CCS patients have prior spinal stenosis.
- Acquired: spondylosis and prior trauma
Klippel-Feil syndrome (congenital fusion of any two cervical vertebrae) is congenital.

Prevention 

Injury can be avoided or minimized through the use of seat belts, rule revisions, proper technique, and the appropriate selection and usage of protective gear during sports.

Accompanying Conditions 

Soft tissue trauma, whiplash-associated diseases (WADs), closed head traumas, and SCI


Diagnosis 

The Glasgow Coma Scale (GCS) is often present in acute presentations with cervical hyperextension as the mechanism and complaints of neck discomfort, stiffness, or headaches as neurologic symptoms.


clinical assessment 
External symptoms of head and neck trauma, such as abrasions, lacerations, or contusions, can reveal the mechanism and any accompanying injuries.
Neck tenderness's presence, intensity, and location aid in localizing the affected structure(s):
- Posterior, midline bony soreness suggests a fracture may be present.
- Soft tissue soreness on the lateral or paraspinal sides may indicate a muscle or ligament damage.
- Frontal discomfort indicative of vascular injury
Carotid bruit is an indication of carotid dissection.
Neurologic examination: Paresthesias and paralysis may be signs of SCI or a stroke brought on by BCVI:
- CCS frequently manifests as an upper extremity > lower extremity, distal > proximal symptom distribution.
Extremity weakness or paralysis is the predominant sensory change, with paresthesias and dysesthesias present below the site of the lesion.
Bladder or bowel incontinence could happen.

Differential Diagnosis: Osteoarthritis, Cervical Radiculopathy, Acute or Chronic Disc Pathology (Herniation or Internal Disruption)

For CCS, Carotid or vertebral artery dissection, Bell's palsy, bilateral brachial plexus injuries,

Diagnostic tests and laboratory results 

Initial examinations (lab, imaging)
Using either the Canadian C-Spine Rule (CCR) or the National Emergency X-Ray Utilization Study (NEXUS) criteria, low-risk individuals can be cleared clinically (without imaging):
- CCR: If all of the following criteria are met, a stable, 16-year-old patient with acute head and neck injuries and no prior history of cervical spine disease or surgery may be discharged:
No hazardous mechanisms or paresthesias in the extremities (GCS 15).
65 years old
- NEXUS: clinically clear if all of the following are true: No posterior, midline C-spine tenderness No signs of intoxication Normal level of alertness At least one "low-risk factor" (e.g., simple rear-end MVA, ambulation at the accident scene, lack of midline cervical tenderness, delayed onset of neck pain, or sitting at the time of exam)
There are no distracting injuries and no focused or neurologic deficits.
– CCR (90-100%/1-77%), and NEXUS (83-100%/13-46%) have reported sensitivity/specificity values.

Based on the suspected injury and level of clinical suspicion, recommend imaging in patients with high-risk mechanisms or worrying historical/physical examinations:
- Plain radiographs: in some individuals who cannot be clinically cleared but are still in the category of low suspicion:
Sensitivity to C-spine damage 39%
Dynamic: flexion-extension; only in the absence of neurological impairments or mental impairment, inadequate identification of ligamentous injury, limited diagnostic value
– Given its high sensitivity (90–100%), axial CT from the occiput to T1 with coronal and sagittal reconstructions has replaced plain radiography as the test of choice in instances with a moderate to high clinical suspicion of C-spine damage.
- MRI: the preferred test for CCS with direct vision of traumatic cord lesions (edema or hematomyelia), soft tissue compressing cord, and/or canal stenosis; detects ligamentous injury and abnormalities of intervertebral discs and soft tissues; less effective for fractures.
- CT angiography: This procedure uses images of the cervical and cerebral vascular systems to identify BCVI; when a 16-slice CT scanner is utilized, sensitivity is close to 100%.
An option is MR angiography, however its usefulness is constrained by its sensitivity of 47–50%.


Test interpretation: Corticospinal tract disruption in the white matter of the lateral column is assumed to be the cause of CCS.
Acute cervical strain/sprain: Models suggest myofascial tearing, edema, and inflammation. BCVI: intimal disruption, leading to thrombosis and embolization.


Aspects of Geriatrics

Osteopenia may restrict fracture visualization on x-rays—CT is more accurate. Degenerative changes of the C-spine may be misinterpreted with acute traumatic changes.
Even with low-velocity trauma, degenerative disease and osteopenia enhance the likelihood of upper cervical spine injury.

Child Safety Considerations 

Up to 50% of juvenile cervical spine injuries are caused by SCIWORA, which has a high incidence at age 9 years. MRI is used to find injuries.

Treatment-Related General Steps 
Whiplash/WAD - Cervical collar has little to no benefit. If offered, utilize for up to 72 hours.
- Early multiprofessional intervention (such as pain management and psychology) had no benefits.
(5)[C]
- There are no differences in outcomes between physical therapy (PT) and passive treatment (immobilization, rest); increase activity levels as tolerated
- In the absence of a fracture, there is no preferred course of action.
Fractures: Imaging-based stability assessment These conditions call for decompression and stabilization:
Clinical worsening or failure to recover despite conservative treatment in incomplete SCIs with spinal canal impairment
- Hangman fracture: anterior displacement of C2 over C3, bilateral C2 pedicle fractures, and traumatic spondylolisthesis; can be unstable
Halo vest immobilization for 12 weeks, until normal flexion-extension films were obtained.
- Broken odontoid bones: Treat each type individually:
I: to apex; often stable; up to 12 weeks of external immobilization with a cervical collar (less frequently a halo vest).
II: the most prevalent, at the base of the dens, typically unstable; nonunion rates of up to 67% with halo immobilization alone, particularly with dens displacement >6 mm or age >50 years
III: generally stable; immobilization for 12 to 20 weeks in a cervical collar or halo - hyperextension teardrop fractures
For 8 to 14 weeks if stable, use a stiff collar or cervicothoracic brace. For up to 3 months if unstable, wear a halo brace.
CCS: cervical collar neck immobilization, physical treatment (PT) and occupational therapy (OT)
Cervical strain: there is no difference in outcomes between active (PT) and passive (immobilization, rest) treatment; a soft cervical collar may be used for 10 days to relieve symptoms, and then movement and activity levels may be increased as tolerated; ambiguous EBM guidelines

Medication
Fractures: analgesics for pain management
CCS: Methylprednisolone 30 mg/kg IV over 15 minutes and then 5.4 mg/kg/hr IV continuously for 23 hours should be considered within 8 hours after the injury.
If infusion is prolonged for 48 hours, particularly if first bolus administration is put off after injury, further improvement in motor function recovery may be noticed.
BCVI: IV heparin for anticoagulation, then warfarin for three to six months, then long-term antiplatelet medication; antiplatelet drug as single first therapy in patients with anticoagulation contraindications.
Acetaminophen or NSAIDs for cervical strain. For acute cervical strain, adding cyclobenzaprine is not particularly advantageous.


Motives for Additional Consultation 
Immobilize the patient and send them to the ED for evaluation and clearance if a cervical spine injury is suspected.
Urgent spinal surgeon consultation for any concerns regarding an unstable fracture or SCI

Fractures with hangman fractures require surgical stabilization for significant angulation or subluxation, disruption of the intervertebral disc space, or failure to achieve alignment with an external orthosis.
- Broken odontoid bones
Type II: Early surgical stabilization is advised in cases where age is greater than 50, the dens displacement is greater than 5 mm, and certain fracture patterns exist.
Type III: After trying external immobilization, surgical intervention is frequently reserved for situations of nonunion or malunion.

In cases of unstable damage, herniated discs, or declining neurologic function, surgical decompression/fixation is advised.
BCVI: If a pseudoaneurysm, total occlusion, or vascular transection is present, surgical and/or angiographic intervention may be necessary.


Admissions: Depending on the injury, clinical judgment, imaging results, co-occurring injuries, and necessity for surgical intervention; ATS protocol with backboard and collar

Patient Follow-Up Monitoring
Serial imaging is used to monitor patients with known injuries under the supervision of a physician.


The most crucial aspect of the prognosis is the patient's current neurologic condition.
Fractures: 93-100% of hangman fractures fuse after 8 to 14 weeks of external immobilization.
- Odontoid fracture, fusion rate by type: type I, 100% with external immobilization alone; type II, nonunion rates as high as 67% with halo immobilization alone, particularly with dens displacement >6 mm or age >50 years; type III, 85% with external immobilization, 100% with surgical fixation
BCVI: Patients with early diagnosis and antithrombotic therapy experience fewer neurologic sequelae.
Spontaneous recovery of motor function in >50% of patients with CCS over a period of weeks. Patients who are younger are more likely to regain function. Functions of the lower extremities return after the bowel, bladder, and legs.
WAD: Increased initial pain intensity, pain-related disability, and cold hyperalgesia are prognostic variables for the development of late whiplash syndrome (>6 months of symptoms interfering with normal activities).

Complications BCVI: embolic ischemic events and pseudoaneurysm development Fractures: instability or malunion/nonunion needing second operation, reactions, and infection associated to orthosis

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