Cervical Spine Trauma: Dislocation and Subluxation

By admin On Jan 10, 2024

Ovid: 5-Minute Orthopaedic Consult

Editors: Frassica, Frank J.; Sponseller, Paul D.; Wilckens, John H.

Title: 5-Minute Orthopaedic Consult, 2nd Edition

> Table of Contents > Cervical Spine Trauma: Dislocation and Subluxation

Cervical Spine Trauma: Dislocation and Subluxation

Dhruv B. Pateder MD

Basics

Description

11,000 cases annually require surgery.
Average hospital stay: 9.4 days (1,2); a prolonged stay partly attributable to delay in diagnosing vertebral injuries (frequently missed)
Careful trauma-patient evaluation,
increased understanding of injury patterns, and advanced imaging and
treatment have decreased the morbidity and mortality associated with
spinal column injuries (1,2).
Classification:
- The Denis 3-column theory (3,4):
  - To determine vertebral fracture stability
  - Unstable fracture: Disruption of 2 columns
- The Ferguson-Allen classification (5):
  - Based on the mechanism of injury
  - 7 categories: Compressive flexion
    (“teardrop” fractures), vertical compression (burst fractures),
    distractive flexion (dislocations), compressive extension, distractive
    extension, lateral flexion, and miscellaneous cervical spine flexion

General Prevention

Seat belts and head rests on car seats
Possibly air bags
Strict cervical spine immobilization for all trauma patients

Epidemiology

Incidence

Up to 75% of fractures of the vertebral column occur in the cervical spine (1,2).
5–10% of blunt trauma patients have cervical spine injuries (1,2).
Serious diving accidents have a 50% incidence of cervical spine injury (1,2).

Risk Factors

Young males 18–25 years old

Genetics

Many skeletal dysplasias predisposing to
traumatic injuries have a genetic basis, and some atraumatic
instabilities are associated with a genetic predisposition.
- Down syndrome is associated with a chromosomal disorder (trisomy 21).
- Rheumatoid arthritis has a genetic predisposition, which seems to be associated with certain HLA markers.
Traumatic cervical dislocations have no genetic predisposition.

Etiology

Traumatic:
- Motor vehicle collision
- Diving in shallow water
- Blunt trauma
Atraumatic:
- Rheumatoid arthritis
- Down syndrome
- Skeletal dysplasias

Associated Conditions

Neurogenic shock
Head injury
Cervical spine fractures
Chest and abdominal trauma
Extremity trauma

Diagnosis

Signs and Symptoms

Neck pain after trauma
Occasionally, neck deformity, especially in rotatory subluxations or unilateral facet dislocations
Persistent asymmetric posturing or head tilt may indicate cervical subluxation or dislocation.
Neurologic injury may take the form of
weakness, numbness, bowel or bladder incontinence, complete
quadriplegia, or 1 of the incomplete spinal cord injury syndromes
(Brown-Séquard, central cord, anterior cord, posterior cord).

Physical Exam

All trauma evaluations begin with assessment of airway, breathing, and circulation (6).
Evaluation of the cervical spine should
begin only after the patient is hemodynamically stable and
life-threatening injuries have been ruled out.
Initial radiographs of the cervical spine, chest, and pelvis are useful in prioritizing therapy.
The initial neurologic examination (with
the patient in a neck collar) requires careful documentation, including
time of injury, and time and details of field and hospital examinations.
- Sensory examination: Evaluate dermatomes, light touch, pin prick, temperature, and perianal sensation.
- Motor examination:
  - Upper extremities: Grade the deltoids,
    triceps, biceps, wrist flexors and extensors, finger abductors and
    adductors, and grip strength.
  - Lower extremities: Test the iliopsoas,
    quadriceps, hamstrings, hip abductors/ adductors, tibialis anterior,
    extensor hallucis longus, and gastrocnemius–soleus complex.
  - Grade each muscle on a 0–5-point scale.
- Do not use phrases such as “moves
  everything” or “feels everything” because the physical examination
  provides a temporal sequence for a potentially evolving neurologic
  injury.
- Rectal examination: Performed by the
  spine surgeon to assess tone, volitional control, and sensation to
  light touch and pin prick.
Examine the head and neck for tenderness and pain on motion.
- If painful, immobilize the head and neck until adequate physical/radiologic examinations.
Suggested motor checkpoints:
- C4: Diaphragm
- C5: Deltoid and elbow flexors
- C6: Wrist extensors
- C7: Elbow extensors
- C8: Finger flexors (profundus)
- T1: Intrinsics (finger abductors)
- L2: Hip flexors
- L3: Knee extensors
- L4: Ankle dorsiflexors
- L5: Great toe extensors
- S1: Ankle plantar flexors
- S4–5: Voluntary anal contraction
Suggested sensory checkpoints:
- C2: Occiput
- C4: Tip of shoulder
- C5: Regimental patch (lateral shoulder)
- C6: Thumb
- C7: Long finger
- C8: Little finger
- T1: Medial epicondyle
- T4: Nipples
- T10: Umbilicus
- L1: Groin
- L3: Patella
- L4: Medial malleolus
- L5: Great toe and first web space.
- S1: Lateral heel
- S2: Popliteal fossa
- S3: Ischial tuberosity
- S4–5: Perianal

Tests

Lab

Estimated lung vital capacity of at least 20% of predicted is necessary.
If vital capacity is <20% or 1,000 mL, a tracheostomy may be required.

Imaging

Radiographic evaluation of the cervical spine:
- For any potentially neurologic injury
- The AP view allows evaluation of the interspinous distance, alignment, and symmetry of uncovertebral joints.
- Lateral view:
  - Most important view
  - Can detect approximately 82% of injuries to the cervical vertebrae (2)
  - The C7–T1 junction must be visualized adequately because injuries at this level are not uncommon.
  - If this level cannot be visualized, a “swimmer’s view” (arm abducted over the head and body slightly rotated) may be useful.
  - If C7–T1 still is not visualized, a CT scan at that level is necessary.
- The open-mouth view is excellent for
  visualizing the dens and the overhanging lateral masses, but its
  acquisition frequently is limited by associated pain and the high
  degree of patient cooperation required.
- Oblique views are excellent for
  visualizing the neural foramen and lamina, but their use in the trauma
  situation is controversial and generally is not a part of the trauma
  series.
- Patient pain, cervical spine tenderness, or neurologic symptoms: Possible ligamentous injury even with negative radiographs
  - Lateral flexion–extension views may be indicated to evaluate for dynamic instability of the cervical vertebrae.

P.67

CT:
- Evaluates any bony abnormalities
- Usually obtained if injury is questionable on standard cervical spine radiographs
- Standard of care for evaluation of any loss of middle column height
- Planar reconstructions can be very valuable in surgical planning.
MRI:
- Evaluates soft-tissue, pathologic, and ligamentous injuries
- Also useful for evaluating neurologic deficits that cannot be explained radiographically
- May be necessary for uncooperative or obtunded patients

Differential Diagnosis

Pseudosubluxation (other than normal ≤3 mm at C2 in children)
Cervical spine fractures with instability
Injuries at multiple levels
Muscular torticollis

Treatment

General Measures

Resuscitation and emergency measures:
- Airway, breathing, and circulation
- Strict immobilization during extraction and transportation (and intubation if necessary)
Emergency department assessment:
- Complete (with neurologic) assessment
- Full radiographic evaluation
Emergency treatment:
- Traction for reduction of dislocations (MRI for facet dislocations)
- Methylprednisolone:
  - Start within 8 hours of spinal cord injury to help preserve neuronal structures.
  - Dose: A 30-mg/kg bolus intravenously followed by 5.4 mg/kg/h for 23 hours
- Surgery for irreducible dislocations with neurologic deficit and deterioration
For stable injuries, immobilization may be necessary for a short period.
The treatment of unstable injuries may vary from immobilization to surgical stabilization.

Activity

After the dislocation is stabilized, activity can be begun and advanced gradually.

Special Therapy

Radiotherapy

Decreases tumor size and burden in patients with pathologic thoracolumbar fractures

Physical Therapy

Important role in mobilizing spinal injury patients and for those with neurologic injury
May be helpful after healing to treat residual pain and stiffness
Wheelchairs are individualized to the patient.
Lower extremity bracing and orthotics for upper extremity function may be beneficial.

Surgery

Occipitocervical dissociation requires an occiput-to-C2 posterior fusion/instrumentation.
Atlantoaxial instability should include
bracing for children and those with ≤7 mm of translation in flexion and
fusion for patients with >7 mm of persistent translation.
Hangman’s fracture–dislocation or traumatic spondylolisthesis:
- Can be treated with closed reduction and a Minerva cast in children
- Halo immobilization or posterior open reduction and stabilization may be necessary, depending on the type of fracture.
Facet dislocations may require open reduction and stabilization for failed closed reduction.

Follow-up

Patients with neurologic injuries require long-term
rehabilitation, including education, bladder and bowel program, family
education, physical and occupational therapy, and psychologic
counseling.

Prognosis

Prognosis depends on injury severity.
- Neurologically intact patients with low-energy injuries have excellent recovery.
- Patients with neurologic injury have major issues, potentially requiring alteration in their personal and professional lives.

Complications

Surgical complications: Infection, neurologic injury, pseudarthrosis, chronic pain, and disability
Other complications include neurologic
injury, spinal deformity, chronic pain, and skin problems from pressure
points on neck braces.

Patient Monitoring

Neurologic monitoring (including somatosensory-evoked
potentials and motor monitoring) during reduction maneuvers and surgery
may increase the safety of the procedure.

References

1. Viano
DC. Effectiveness of safety belts and airbags in preventing fatal
injury. In: Proceedings of Frontal Crash Safety Technologies, SAE
Technical Paper Series. Warrendale, PA: Society of Automotive
Engineers, 1991:159–171.

2. West
OC, Anbari MM, Pilgram TK, et al. Acute cervical spine trauma:
diagnostic performance of single-view versus three-view radiographic
screening. Radiology 1997;204:819–823.

3. Denis F. The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine 1983;8:817–831.

4. Denis F. Spinal instability AS defined by the three-column spine concept in acute spinal trauma. Clin Orthop Relat Res 1984;189:65–76.

5. Ferguson RL, Allen BL, Jr. A mechanistic classification of thoracolumbar spine fractures. Clin Orthop Relat Res 1984;189:77–88.

6. American
College of Surgeons Committee on Trauma. Advanced Trauma Life Support
Program for Doctors, 6th ed. Chicago: American College of Surgeons,
1997.

Miscellaneous

Codes

ICD9-CM

839.01 C-1 dislocation
839.02 C-2 dislocation
839.03 C-3 dislocation
839.04 C-4 dislocation
839.05 C-5 dislocation
839.06 C-6 dislocation
839.07 C-7 dislocation

Patient Teaching

Skin care and positioning to prevent flexion contractures
Education to prevent pressure ulceration, respiratory, and urinary infections

FAQ

Q: What imaging modality is considered a part of the “trauma series” in evaluating a patient?

A: Lateral cervical spine, AP chest, and AP pelvis radiographs.

Q: What is the last vertebrae that must be visualized for an adequate C-spine lateral radiograph?

A: C7–T1 junction.