Spinal Trauma: MCCQE1 Preparation Guide

Introduction

Spinal trauma is a high-stakes topic for the MCCQE1. As a future Canadian physician, you are expected to demonstrate the CanMEDS Medical Expert role by rapidly assessing, stabilizing, and managing patients with potential spinal column or spinal cord injuries (SCI).

In the Canadian context, understanding the Canadian C-Spine Rule (CCR) is paramount for resource stewardship and patient safety. This guide covers the pathophysiology, assessment, and management of spinal trauma, tailored specifically for MCCQE1 preparation.

CanMEDS Corner

Medical Expert: Recognizing neurogenic shock and unstable fractures.
Collaborator: Working with neurosurgery, orthopedics, and rehabilitation teams.
Health Advocate: Promoting injury prevention (e.g., seatbelts, diving safety).

Anatomy and Pathophysiology

Understanding the functional anatomy is crucial for localizing lesions.

The Three-Column Concept (Denis)

Stability of the spine is often assessed using the three-column theory. Instability typically exists if two or more columns are disrupted.

Column	Components
Anterior	Anterior Longitudinal Ligament (ALL), anterior 2/3 of the vertebral body and annulus fibrosus.
Middle	Posterior Longitudinal Ligament (PLL), posterior 1/3 of the vertebral body and annulus fibrosus.
Posterior	Posterior ligament complex (supraspinous, interspinous, ligamentum flavum, capsule), pedicles, facets, lamina, spinous processes.

Spinal Cord Syndromes

Complete vs. Incomplete

Complete SCI: No motor or sensory function below the level of injury (AIS A).

Incomplete SCI: Some preservation of motor or sensory function below the level of injury (AIS B-E). Sacral sparing (sensation at anal mucocutaneous junction) is the hallmark.

Acute Management & Assessment

Follow the ATLS (Advanced Trauma Life Support) protocol, which is the standard of care in Canada.

Step 1: Primary Survey (ABCDE)

Airway: Assess with C-spine immobilization. If intubation is needed, use manual in-line stabilization (MILS).
Breathing: High C-spine injuries (C3-C5) affect the phrenic nerve (“C3, 4, 5 keep the diaphragm alive”).
Circulation: Identify shock. Differentiate hemorrhagic (tachycardia) from neurogenic (bradycardia).
Disability: GCS and pupillary exam. Gross motor/sensory check.
Exposure: Log roll to inspect the back for step-offs, tenderness, or bruising.

Step 2: Immobilization

Apply a rigid cervical collar.
Maintain spinal precautions (log roll, spine board for transport only—remove ASAP to prevent pressure ulcers).

Step 3: Secondary Survey & Neurological Exam

Detailed ASIA (American Spinal Injury Association) exam.
Test for sacral sparing (anal sensation/tone).
Check reflexes (bulbocavernosus reflex return signals end of spinal shock).

Step 4: Imaging Decision (Canadian C-Spine Rule)

Determine if imaging is required based on risk factors.

🚨

Critical MCCQE1 Concept: Never clear a C-spine in a patient who is obtunded, intoxicated, or has a distracting injury based on clinical exam alone. They require imaging (CT is the gold standard).

The Canadian C-Spine Rule (CCR)

This is a high-yield topic for MCCQE1 preparation. The CCR allows physicians to safely rule out cervical spine injury without radiography in alert, stable trauma patients.

1. High-Risk Factors (Mandate Radiography)

If ANY of the following are present, imaging is required:

Age ≥ 65 years
Dangerous mechanism (e.g., fall >1m/5 stairs, axial load to head, high-speed MVC, rollover, ejection, motorized RV, bicycle collision)
Paresthesias in extremities

2. Low-Risk Factors (Allow Range of Motion Assessment)

If NO high-risk factors, check for any low-risk factor that allows safe assessment of range of motion:

Simple rear-end MVC
Sitting position in ED
Ambulatory at any time
Delayed onset of neck pain
Absence of midline c-spine tenderness

If NONE of these low-risk factors apply, imaging is required.

3. Range of Motion (ROM)

Can the patient actively rotate their neck 45° left and right?
No (Unable): Radiography required.
Yes (Able): No radiography required.

Clinical Management

1. Hemodynamic Management (Neurogenic Shock)

Goal: Maintain spinal cord perfusion.
Target: Mean Arterial Pressure (MAP) > 85 mmHg for the first 7 days.
Fluids: Isotonic crystalloids (NS or RL). Avoid fluid overload.
Vasopressors: Norepinephrine or Phenylephrine are preferred. Atropine may be needed for severe bradycardia.

2. Steroids (Methylprednisolone)

Current Canadian Context: The use of high-dose steroids (NASCIS protocols) is controversial.
It is not a standard of care in many Canadian centres due to risks (infection, hyperglycemia, GI bleed) outweighing benefits.
MCCQE1 Tip: Unless the exam question specifically references a protocol requiring it, prioritize ABCs and hemodynamic support (MAP goals) over steroids.

3. Surgical Decompression

Indicated for:
- Progressive neurological deficit.
- Incomplete injury with continued compression.
- Unstable fractures/dislocations.

Specific Fracture Types

Region	Fracture Name	Mechanism	Stability
C1	Jefferson Fracture	Axial load (e.g., diving). Burst fracture of C1 ring.	Unstable.
C2	Hangman’s Fracture	Hyperextension (e.g., hanging, chin hits dashboard). Bilateral pedicle fracture.	Unstable.
C2	Odontoid Fracture	Type I (tip - stable), Type II (base - unstable), Type III (body - variable).	Type II is high risk for non-union.
T/L	Chance Fracture	Flexion-distraction (seatbelt injury). Horizontal fracture through body/posterior elements.	Unstable. Associated with GI injuries.

Key Points to Remember for MCCQE1

High-Yield Review

Imaging: CT spine is the modality of choice for trauma. MRI is for soft tissue/cord/ligament assessment.
Neurogenic Shock: Hypotension + Bradycardia. Treat with fluids and vasopressors. Do not confuse with hypovolemic shock (tachycardia).
Autonomic Dysreflexia: Occurs in established SCI (T6 or above). Triggered by noxious stimulus (full bladder, constipation). Hypertension + Headache + Bradycardia. Treat by removing stimulus (catheterize).
Clearance: Use Canadian C-Spine Rule for alert patients. Obtunded patients cannot be cleared clinically.

Sample Question

Clinical Scenario

A 24-year-old male is brought to the Emergency Department following a diving accident where he struck his head on the bottom of a shallow pool. On arrival, he is alert but complains of inability to move his legs. His vital signs are: BP 80/40 mmHg, HR 52 bpm, RR 18/min, O2 sat 98% on room air. His skin is warm and dry. Physical examination reveals flaccid paralysis of the lower extremities and loss of sensation below the nipple line.

Question

Which one of the following is the most appropriate initial pharmacological intervention to address his hemodynamic status?

A. Administer bolus of 2L Ringer’s Lactate
B. Administer IV Atropine 0.5 mg
C. Administer IV Norepinephrine
D. Administer IV Methylprednisolone 30 mg/kg bolus
E. Administer IV Dopamine

Explanation

The correct answer is:

C. Administer IV Norepinephrine

Detailed Analysis

Diagnosis: The patient presents with classic signs of neurogenic shock secondary to a high thoracic or cervical spinal cord injury. The clinical triad includes:

Hypotension (BP 80/40) due to loss of sympathetic vasomotor tone (vasodilation).
Bradycardia (HR 52) due to unopposed parasympathetic (vagal) tone.
Warm, dry skin due to peripheral vasodilation (distinguishing it from hypovolemic shock where skin is cold/clammy).

Management Logic:

Option C (Norepinephrine): This is the preferred vasopressor for neurogenic shock. It has both alpha-adrenergic (vasoconstriction) and beta-adrenergic (inotropic/chronotropic) effects, addressing both the hypotension and the relative bradycardia while restoring perfusion pressure to the spinal cord. The goal is often to maintain MAP > 85 mmHg.
Option A (2L Fluids): While fluid resuscitation is part of the initial management, neurogenic shock is a distributive shock, not primarily hypovolemic. Aggressive fluid overload can lead to pulmonary edema and cord swelling. A modest fluid challenge is appropriate, but vasopressors are definitive for neurogenic shock.
Option B (Atropine): Atropine is used for symptomatic bradycardia, but it does not address the significant hypotension caused by vasodilation.
Option D (Methylprednisolone): High-dose steroids are controversial and not the priority for hemodynamic stabilization. The immediate life-threatening issue is perfusion (ABCs).
Option E (Dopamine): While Dopamine was historically used, Norepinephrine is currently recommended as the first-line agent for neurogenic shock in many guidelines due to a cleaner side-effect profile and efficacy.

Canadian Guidelines

For MCCQE1 preparation, be familiar with:

Canadian C-Spine Rule (CCR): Developed in Canada, this is the standard for clinical clearance of the cervical spine.
Choosing Wisely Canada: Recommends against imaging the spine in low-risk trauma patients who meet the CCR criteria to reduce unnecessary radiation.
Acute Management of Spinal Cord Injury: Guidelines emphasize maintaining mean arterial pressure (MAP) > 85 mmHg for 5-7 days post-injury to improve neurological outcomes.

References

Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-spine rule for radiography in alert and stable trauma patients. JAMA. 2001;286(15):1841-1848.
Medical Council of Canada. MCCQE Part I Objectives: Trauma.
American College of Surgeons. Advanced Trauma Life Support (ATLS) Student Course Manual. 10th ed.
Fehlings MG, et al. A Clinical Practice Guideline for the Management of Patients With Acute Spinal Cord Injury: Recommendations on the Role of Baseline Magnetic Resonance Imaging in Clinical Decision Making and Outcome Prediction. Global Spine J. 2017.
Choosing Wisely Canada. Emergency Medicine: Imaging for spinal trauma.