01Approach to the Critical Patient/attcp55

Immediate stabilization

›Spinal precautions

›Rigid cervical collar application before any movement

›Manual in-line stabilization during collar placement

›Log-roll technique for patient repositioning

›Spinal motion restriction maintained until fracture characterized

›Full backboard if polytrauma

›Semi-recumbent positioning tolerated once collar secured

›Do NOT remove collar or test active ROM until imaging complete

›Airway priorities

›High cervical cord injury risk — diaphragmatic innervation C3-C5

›Monitor respiratory rate and SpO2 continuously

›Early intubation threshold lowered if respiratory compromise

›Video laryngoscopy preferred for intubation in suspected cervical injury

›In-line stabilization maintained throughout intubation

›Avoid hyperextension

›Neurogenic shock pattern recognition

›Hypotension with paradoxical bradycardia

›Warm vasodilated extremities despite low BP

›Hemodynamic targets

›MAP >85 mmHg target in suspected spinal cord injury

›Vasopressor initiation if MAP <85 mmHg after adequate volume

›Norepinephrine first-line vasopressor for neurogenic shock

›Atropine 0.5–1 mg IV for symptomatic bradycardia

›Repeat every 3–5 minutes to maximum 3 mg

›Temporary pacing if refractory

Monitoring and escalation

›Monitoring bundle

02History/hx74

Mechanism and presentation

›Mechanism of injury

›High-energy trauma in younger patients

›Motor vehicle collision

›Diving injury

›Contact sports

›Low-energy falls in elderly

›Ground-level fall predominant mechanism

›Falls account for ~92% of cases in elderly cohorts

›Atraumatic or minimal trauma

›Pathologic fracture concern

›Osteoporosis, malignancy, or infection

›Primary symptoms

›Upper cervical or suboccipital pain

›Often poorly localized

›Radiation to occiput or shoulders

›Restricted neck rotation

›Patient holding head manually

›Torticollis suggesting atlantoaxial instability

›Timing of symptom onset

›Acute onset post-trauma

›Elderly may present days later with vague complaints

Alarm features and neurological symptoms

›Neurological deficits

›Motor weakness in extremities

›Upper extremity weakness (C5-T1 myotomes)

›Lower extremity weakness

›Sensory disturbance

03Physical Exam/exam63

Vital signs and general appearance

›Hemodynamic assessment

›Blood pressure pattern

›Hypotension — SBP <90 mmHg

›Neurogenic shock if bradycardia present simultaneously

›Heart rate

›Bradycardia with hypotension suggests neurogenic etiology

›Tachycardia suggests hemorrhage or pain

›Respiratory rate and SpO2

›High cervical cord injury may impair diaphragm

›Increasing respiratory rate as fatigue marker

›General appearance

›Patient holding head in protective posture

›Bilateral hand support of head

›Refusal to move neck

›Altered mental status

›Concurrent TBI concern

›Intoxication as contributing mechanism

Cervical spine and neurological exam

›Cervical spine palpation

›Midline tenderness at C1-C2 level

›Palpate with collar in place — do not remove until cleared

›Step-off or crepitus at occiput-C2

›Suboccipital tenderness

›Upper cervical localizing finding

›Paraspinal spasm

›Motor examination

›Upper extremity strength by myotome

04Differential Diagnosis/ddx37

Life-threatening and urgent diagnoses

›Upper cervical fracture spectrum

›Odontoid fracture (C2 dens)

›ICD-10 S12.100A — fracture of dens

›Most common cervical fracture in patients >65

›Hangman fracture (C2 pars interarticularis)

›ICD-10 S12.200A — bilateral pars fracture

›Different fracture line on CT — posterior elements

›Jefferson fracture (C1 burst fracture)

›ICD-10 S12.000A — C1 fracture

›Coexists with odontoid fracture in ~9% of upper cervical injuries

›Ligamentous and dissociative injuries

›Atlanto-occipital dissociation

›Ligamentous disruption — often fatal

›Type I odontoid fracture may be a clue

›Transverse ligament rupture

›Atlantoaxial instability without bony fracture

›MRI for ligamentous evaluation

›Atlantoaxial rotatory subluxation

›Torticollis presentation

›CT with 3D reconstruction differentiates

Mimics and associated diagnoses

›Congenital and chronic mimics

›Os odontoideum

›Congenital anomaly mimicking Type II fracture

›Smooth, well-corticated margins on CT distinguish from acute

›Cervical strain or sprain

›No fracture on imaging

05Laboratory Tests/lt43

Trauma and resuscitation labs

›Core trauma panel

›Complete blood count

›Hemorrhage quantification

›Baseline hemoglobin for surgical planning

›Comprehensive metabolic panel

›Electrolytes and renal function

›Antibiotic or anesthetic dosing input

›Coagulation studies

›PT/INR and aPTT

›Anticoagulant reversal planning

›Type and screen

›Surgical anticipation

›Massive transfusion preparation if polytrauma

›Markers of perfusion and severity

›Lactate

›≥2 mmol/l suggests organ hypoperfusion

›Neurogenic shock vs hemorrhagic shock differentiation

›Arterial blood gas if respiratory compromise

›PaO2 and PaCO2 in mmHg

›pH and base deficit

Targeted and preoperative labs

›Pathologic fracture workup

›ESR and CRP

›Elevated in infection or inflammatory arthropathy

›Markedly elevated in metastatic disease

›Serum protein electrophoresis

›Multiple myeloma screening

06Diagnostic Tests/dt107

Scoring Systems

›Anderson and D'Alonzo classification

›Type I — avulsion of tip of dens above transverse ligament

›Usually stable

›Low nonunion risk

›Management: cervical collar

›Type II — fracture at base of dens at junction with C2 body

›Highest instability and nonunion risk (~40–60% nonunion with collar alone)

›Most common type (~55% of odontoid fractures)

›Management controversial: collar vs halo vs surgery

›Type III — fracture extends into C2 vertebral body

›Variable stability

›Moderate nonunion risk

›Bony fusion rate ~96% with conservative management

›Roy-Camille subtypes for Type II

›Anterior oblique fracture line

›Favors anterior odontoid screw fixation

›Posterior oblique fracture line

›Less favorable for anterior screw

›Posterior C1-C2 fusion preferred

›Horizontal fracture line

›Variable approach

›Instability thresholds

›Displacement ≥5 mm defines instability

›Associated with higher nonunion risk

›Surgical fixation typically recommended

›Angulation ≥11° defines instability

›Combined with displacement increases risk further

›Comminution as independent instability marker

›Frailty and risk scoring

›Modified Frailty Index (mFI-5)

›Guides surgical risk in elderly

›Higher score predicts worse surgical outcomes

›Clinical Frailty Scale (CFS)

›Scale 1–9

›CFS ≥5 associated with increased surgical morbidity

›Charlson Comorbidity Index

›Guides overall surgical risk assessment

›NEXUS criteria

›Used to determine need for cervical imaging in ED

›Low sensitivity for odontoid fracture in elderly — low threshold to image

›Canadian C-Spine Rule

›Validated decision rule for imaging indication

›Age ≥65 is high-risk criterion mandating CT

MRI

›MRI cervical spine indications

›Neurological deficit present

›Spinal cord injury evaluation

›Cord contusion or edema characterization

›Ligamentous injury evaluation

›Transverse ligament integrity

›T2 signal disruption indicates rupture

›Epidural hematoma concern

›Cord compression assessment

›Emergent surgical indication if compressive

›MRI findings in odontoid fracture

›Fracture edema

›T2 high signal at fracture site

›STIR sequence most sensitive

›Cord signal change

›T2 hyperintensity indicates contusion

›Central cord pattern in elderly with stenosis

›Ligamentous disruption

›Alar ligaments

›Transverse ligament

›Tectorial membrane

›MRI limitations

›Not routinely needed if CT negative and neurologically intact

›ACR Appropriateness Criteria 2024 support

›Prolonged scan time requires spinal precautions throughout

›Implant and pacemaker contraindications

CT

›CT cervical spine — reference standard for fracture detection

›Sensitivity >98% for cervical fractures

›Thin-cut axial ≤3 mm

›Sagittal and coronal reformats required

›Replaces plain radiography for acute cervical trauma

›Plain films sensitivity only 36%

›Open-mouth odontoid view insufficient alone

›CT imaging protocol

›Without contrast for acute fracture assessment

›CT angiography added if vertebral artery injury suspected

›Key CT findings to document

›Fracture type by Anderson and D'Alonzo classification

›Displacement in mm

›Anterior vs posterior direction

›Angulation in degrees

›Comminution

›C1 ring integrity — concomitant Jefferson fracture

›Canal compromise

›CT angiography indications

›High cervical fracture with dizziness or visual symptoms

›Vertebral artery injury at C1-C2 level

›Bow hunter syndrome concern

›Fracture line traversing transverse foramen

›Vertebral artery at risk

›ACR Appropriateness Criteria 2024 support CT angiography in these cases

Ultrasound

›Ultrasound role in odontoid fracture

›No primary diagnostic role for bony fracture detection

›CT remains reference standard

›POCUS applications in acute management

›IVC assessment for fluid responsiveness in neurogenic shock

›Cardiac function in hemodynamically unstable patient

›Bedside ultrasound adjuncts

›Focused Assessment with Sonography in Trauma (FAST)

›Polytrauma evaluation for hemopneumothorax

›Pericardial effusion exclusion

›Vascular access guidance

›Central venous access in unstable patients

›Arterial line placement

07Disposition/dispo45

Admission and level of care

›ICU admission indications

›Neurological deficit of any grade

›Spinal cord injury monitoring

›Respiratory function monitoring in high cord injury

›Neurogenic shock

›Vasopressor requirement

›MAP target maintenance >85 mmHg

›Respiratory compromise from high cord injury

›Ventilatory support potential

›Inpatient admission indications

›Unstable fracture pattern

›Type II with displacement ≥5 mm or angulation ≥11°

›Halo vest application or surgical planning

›Elderly requiring optimization

›Pain control

›Fall risk assessment

›Delirium monitoring

›Polytrauma

›Failure of outpatient pain control

Specialist consultation and surgery planning

›Spine surgery consultation triggers

›All Type II odontoid fractures

›Regardless of displacement — given high nonunion risk

›Individualized surgical vs conservative decision

›Any neurological deficit

›Emergent neurosurgery involvement

›Concomitant C1 fracture or ligamentous injury

08Treatment/t82

Immobilization — conservative management

›Cervical collar

›Rigid cervical collar (Philadelphia or Miami J)

›First-line for Type I and stable Type III fractures

›Duration 8–12 weeks

›Worn at all times including sleep

›Preferred in elderly for Type II when surgery declined or high-risk

›Fibrous nonunion without instability is acceptable endpoint in elderly

›Age >75 — collar preferred over halo in most centers

›Halo vest immobilization

›More rigid immobilization than collar

›Indicated for displaced Type II in younger patients

›Age <50 with displacement: halo for 8–12 weeks

›Halo-related complications in elderly

›Pin-site infection

›Aspiration pneumonia risk from restricted neck position

›Dysphagia and pressure sores

›Increased mortality risk in frail elderly — avoid if high risk

Surgical management — Type II fractures

›Anterior odontoid screw fixation

›Preserves C1-C2 rotational motion (~50% of total cervical rotation)

›Preferred when fracture line orientation is favorable

›Anterior-inferior to posterior-superior obliquity ideal

›Contraindications

›Posterior-oblique or horizontal fracture lines

›Significant comminution

›Barrel-chest anatomy limiting approach

›Chronic nonunion >6 months

›Outcomes

›Fusion rates 74–90% with favorable anatomy

›Posterior C1-C2 fusion

›Harms technique (C1 lateral mass — C2 pedicle screws)

›Most versatile — applicable to any fracture pattern

›Rigid fixation — fusion rates >90%

›Magerl technique (transarticular screws)

›Alternative to Harms

›Bilateral screw placement

›Trade-offs

›Sacrifices ~50% of cervical rotation (C1-C2 contribution)

›Higher fusion rate but greater functional restriction

›Surgical outcomes data

›Surgery yields higher fusion rates (74% vs 40%) vs nonoperative

›More complications with surgery (26% vs 18.5%)

›Longer LOS: 13.6 vs 8.1 days

›No mortality benefit demonstrated in most RCT-level evidence

›Cochrane review 2008: insufficient evidence to favor surgery

›2024 meta-analysis: comparable 1-year mortality between groups

Analgesia and medical management

›Pain management

›Acetaminophen

›First-line analgesic — 500–1000 mg orally every 6 hours

›Maximum 4000 mg per day (lower in hepatic impairment)

›NSAIDs — use with caution

›Theoretical concern for impaired bone healing

›Short course only if acetaminophen insufficient

›Opioid analgesics for severe pain

›Short-course prescribing only

›Avoid in elderly — fall risk and sedation

›Hydromorphone 0.5–1 mg IV or 2–4 mg oral for severe acute pain

›Avoid muscle relaxants that mask neurological deterioration

›Bone health optimization

›Vitamin D supplementation

›Target 800–1000 IU daily

›Correct deficiency aggressively (vitamin D3 50,000 IU weekly x 8 weeks if <50 nmol/l)

›Calcium supplementation

›1200 mg elemental calcium daily (combined dietary + supplement)

›Osteoporosis pharmacotherapy

›Bisphosphonate or denosumab after fracture stabilization

›Initiate once surgical wound healing complete if operative

›DVT prophylaxis in immobilized patients

›Low molecular weight heparin

›Enoxaparin 40 mg subcutaneous daily

›Adjusted for renal function (GFR <30 — use UFH or dose-adjusted)

›Sequential compression devices

›Immediate use even before pharmacologic prophylaxis

›Anticoagulant reversal consideration if on warfarin/DOAC preinjury

›Warfarin reversal: vitamin K 10 mg IV + 4-factor PCC

›DOAC reversal per agent-specific reversal agent

›Dysphagia and nutritional support

›Dysphagia screen before oral intake

›Retropharyngeal hematoma risk

›Collar position may impair swallowing

›Nasogastric tube if swallowing unsafe

›Protein-adequate nutrition for fracture healing

›Target 1.2–1.5 g protein/kg/day in elderly

09Special Populations/sp85

Pregnancy

›Imaging considerations in pregnancy

›CT cervical spine remains indicated for high-energy trauma

›Cervical spine CT radiation dose low (~2–3 mSv)

›Risk of undiagnosed unstable fracture outweighs fetal radiation risk

›Shield abdomen and pelvis when possible

›MRI preferred where CT finding equivocal

›No ionizing radiation

›Gadolinium avoided in first trimester

›Management modifications

›Halo vest in pregnancy

›Feasible in first and early second trimester

›Increasingly difficult as uterus enlarges

›Surgical positioning

›Left lateral tilt after 20 weeks to relieve aortocaval compression

›Prone position carries fetal risk — multidisciplinary planning

›Fetal monitoring during any surgical procedure

›Pharmacology

›NSAIDs contraindicated after 30 weeks gestation

›Premature ductus arteriosus closure risk

›Opioid analgesics with caution

›Neonatal opioid withdrawal risk with prolonged use

›LMWH safe for DVT prophylaxis in pregnancy

›Enoxaparin preferred over warfarin

›Continue until ambulatory

Geriatric

›Epidemiology and fracture pattern

›Odontoid fractures are the most common cervical fracture in patients >65

›Account for majority of cervical fractures in patients >80

›Falls account for ~92% of cases in elderly

›30-day mortality ~13%; 6-month mortality ~22% in elderly cohorts

›Frailty independently increases mortality

›Comorbidity burden (CCI) guides prognosis

›Treatment decision framework in elderly

›Non-displaced or minimally displaced Type II

›Rigid cervical collar preferred over halo

›Fibrous nonunion without instability acceptable functional outcome

›95% achieve excellent functional outcome within 6 weeks regardless of bony union

›Displaced or unstable Type II

›Surgical vs conservative decision based on frailty, goals, comorbidities

›mFI-5 and CFS guide surgical risk stratification

›Surgery higher fusion rate but more complications and longer LOS

›Halo vest — avoid in frail elderly

›Pin-site infection risk

›Aspiration pneumonia risk

›Falls risk with altered center of gravity

›Perioperative geriatric considerations

›Delirium prevention bundle

›Orientation cues and sleep hygiene

›Minimize anticholinergic and sedative medications

›Polypharmacy review

›Deprescribing fall-risk medications

›Anticoagulant management

›Early mobilization and physiotherapy

›Goals of care discussion

›Life expectancy vs fracture healing time course

›Palliative approach appropriate in some frail patients

Pediatrics

›Epidemiology in children

›Odontoid fractures uncommon in children

›Pediatric cervical injuries more commonly ligamentous

›Synchondrosis fractures before age 7 (physeal injury at dens base)

›High-energy mechanisms predominant

›Motor vehicle collision

›Non-accidental trauma consideration in infants

›Anatomic considerations

›Synchondrosis fracture (before age 7) distinct from adult Type II

›Through cartilaginous growth plate rather than bone

›Generally excellent healing potential with collar immobilization

›Horizontal fracture line through synchondrosis

›May be confused with Type II on imaging

›Growth plate appearance helps differentiate

›Imaging in pediatrics

›CT with dose-reduction protocols (ALARA)

›Pediatric CT protocols with reduced mAs

›MRI preferred where appropriate to minimize radiation

›Plain radiographs — role more preserved in pediatric vs adult

›Less osteoporotic bone — plain films more diagnostic

›Management

›Synchondrosis fractures — cervical collar 6–12 weeks

›Bony healing expected

›Surgical intervention rarely required

›True odontoid fractures in older children

›Managed similarly to adults

›Pediatric spine surgery consultation

›Down syndrome special consideration

›Ligamentous laxity and atlantoaxial instability at baseline

›Modified management with spine surgery input

10Background/b81

Epidemiology

›Incidence and prevalence

›Represent up to 15% of all cervical spine fractures

›Most common fracture of the axis (C2)

›Most common cervical fracture in patients >65 years

›Bimodal age distribution

›Young adults — high-energy mechanism

›Elderly — low-energy falls

›Increasing prevalence with aging population

›Falls account for ~92% of cases in elderly cohorts

›Outcomes and mortality

›30-day mortality ~13% in elderly

›6-month mortality ~22% in elderly cohorts

›Mortality driven by comorbidities and frailty, not fracture alone

›Neurological injury at diagnosis in ~4% of patients

›Central cord syndrome most common cord injury pattern

›Nonunion risk for Type II

›~40–60% with collar alone

›Displaced fractures carry highest nonunion rates

›Risk factor distribution

›Osteoporosis prevalence in elderly fracture cohort >70%

›Smoking associated with lower union odds (aOR 0.2)

›Frailty independently associated with nonunion and mortality

Pathophysiology

›Anatomical basis

›Odontoid process (dens) is superior projection of C2 (axis) body

›Articulates with C1 (atlas) anterior arch

›Stabilized by transverse atlantal ligament and alar ligaments

›C1-C2 articulation provides ~50% of total cervical rotation

›Loss of C1-C2 mobility with posterior fusion significantly affects rotation

›Transverse atlantal ligament prevents anterior dens displacement

›Rupture allows cord compression between dens and posterior C1 arch

›Fracture mechanism

›Type I — ligamentous avulsion at dens tip by alar ligament

›May indicate occipitocervical dissociation when present

›Type II — shear force at weakest point of dens base

›Watershed zone with poor vascular supply explains high nonunion rate

›Anterior displacement from hyperflexion

›Posterior displacement from hyperextension

›Type III — force propagated into C2 cancellous body

›Better vascular supply — superior healing potential

›Nonunion pathophysiology

›Type II nonunion driven by poor vascular supply at fracture site

›Anterosuperior dental artery and posterior ascending artery supply

›Watershed zone at dens base poorly perfused

›Fibrous nonunion — may be stable and asymptomatic

›Fibrous tissue provides partial stability

›Acceptable outcome in elderly if no instability

›Pseudarthrosis — unstable nonunion with persistent mobility

›Risk of delayed myelopathy

Therapeutic Considerations

›Evidence base for treatment choices

›No high-quality RCT data comparing surgical to conservative management

›Cochrane review 2008: insufficient evidence to favor either approach

›Decision individualized based on fracture pattern, age, frailty

›Surgical fusion higher fusion rates (74% vs 40%)

›Greater complications (26% vs 18.5%)

›Longer LOS (13.6 vs 8.1 days)

›2024 meta-analysis: comparable 1-year mortality between surgical and conservative groups

›Nonunion management principles

›Stable fibrous nonunion without instability — observe

›Many elderly achieve excellent function despite nonunion

›Serial imaging to monitor for late instability

›Unstable pseudarthrosis — surgical revision

›Posterior C1-C2 fusion most commonly performed

›Bone health optimization reduces nonunion risk

›Vitamin D deficiency correction mandatory

›Bisphosphonate timing — after fracture consolidation phase

›Classification-guided management algorithm

›Type I — cervical collar 6–8 weeks

›Rule out occipitocervical dissociation (rare but critical)

›Type II — individualized

›Non-displaced + age <50: halo 8–12 weeks

›Non-displaced + age >75: rigid cervical collar

›Displaced ≥5 mm or angulated ≥11°: surgical fixation recommended

›Type III — cervical collar or halo 8–12 weeks

›Surgery reserved for failed conservative treatment or significant displacement

›Vertebral artery injury management

›Incidence in high cervical fractures — significant

›Fracture line traversing transverse foramen at C1-C2

›CTA for detection

›ACR Appropriateness Criteria 2024 support

›Anticoagulation or antiplatelet therapy if detected

›Balancing stroke prevention vs bleeding risk at fracture site

11Patient Discharge Instructions/pdi40

copy discharge instructions

›Diagnosis and treatment overview

›Diagnosis: fracture of the C2 vertebra (odontoid or dens fracture)

›The dens is the peg-shaped bone at the top of your spine

›You have been given a cervical collar to immobilize and protect your neck

›Wear your cervical collar at all times

›Do not remove the collar except as directed by your specialist

›Wear during sleep

›Wear during bathing unless specifically told otherwise

›Activity restrictions

›Avoid all bending, twisting, or rotating of your neck

›No looking over your shoulder

›Turn your whole body instead

›No lifting greater than 2 kg (4.4 lbs) until cleared by your surgeon

›No driving until cleared by your specialist

›Fall prevention measures

›Remove loose rugs and obstacles from home

›Use grab bars in bathroom

›Use walking aid if recommended

›Medications

›Take pain medications as prescribed

›Acetaminophen 500–1000 mg every 6 hours as needed for pain

›Do not exceed 4000 mg acetaminophen per day

›Take calcium 1200 mg daily and vitamin D 800–1000 IU daily

›These support bone healing

›If prescribed blood thinners — take as directed and do not stop without calling your doctor

›Follow-up appointments

›Spine specialist follow-up within 2 weeks

12References/r41

Guidelines and key sources

›Nouri A, Da Broi M, May A, et al.

›Odontoid Fractures: A Review of the Current State of the Art

›Journal of Clinical Medicine. 2024

›PMID 39458221

›Iyer S, Hurlbert RJ, Albert TJ.

›Management of Odontoid Fractures in the Elderly: A Review of the Literature and an Evidence-Based Treatment Algorithm

›Neurosurgery. 2018

›PMID 29165688

›Nourbakhsh A, Hanson ZC.

›Odontoid Fractures: A Standard Review of Current Concepts and Treatment Recommendations

›Journal of the American Academy of Orthopaedic Surgeons. 2022

›PMID 35266921

›Rizvi SAM, Linnerud H, Rønning PA, et al.

›Traumatic Odontoid Fracture — Proposal of a Treatment Algorithm

›Clinical Neurology and Neurosurgery. 2025

›PMID 40339191

›Hassankhani A, Freeman CW, Banks J, et al.

›ACR Appropriateness Criteria Acute Spinal Trauma: 2024 Update

›Journal of the American College of Radiology. 2025

›Shears E, Armitstead CP.

›Surgical Versus Conservative Management for Odontoid Fractures

›Cochrane Database of Systematic Reviews. 2008

›Avila MJ, Farber SH, Rabah NM, et al.

›Nonoperative Versus Operative Management of Type II Odontoid Fracture in Older Adults: A Systematic Review and Meta-Analysis

›Journal of Neurosurgery Spine. 2024

›PMID 37877937

›Lozano CS, Karthikeyan V, Shakil H, et al.

Evidence & Review