Upper Cervical Trauma Sohail Bajammal, MBChB, MSc November 14, 2006 St. Joseph’s Healthcare, Hamilton Weekly Orthopaedic Teaching Rounds

Upper Cervical Trauma a.k.a. Cranio-cervical Trauma Occipito-cervical Trauma Occipito-atlanto-axial Trauma

Outline The Problem Anatomy X-rays Fractures of O, C1, C2

The Problem Better recognition Improved cars safety: Better pre-hospital care (ATLS, Orthopod) Radiographic finding Improved cars safety: Less mortality at scene, more of OC injury

Evaluation History: mechanism of injury Physical: ATLS Radiology: 2° survey: thorough neurological exam Radiology: 3-views C-spine, CT, MRI

Anatomy

Anatomy Unique anatomy of O-C1-C2 Ligaments: Vertebral artery C1: no body, 2 articular pillars connected by 2 arches C2: dens, flat C1-2 Ligaments: Intrinsic (within spinal canal): Odontoid: alar, apical Cruciate: transverse lig, vertical bands Tectorial membrane: thickening of PLL Extrinsic: Ligamentum nuchae Anterior and posterior atlanto-occipital membrane Anterior and posterior atlanto-axial membrane Joint capsules Vertebral artery

Courtesy of AnatomyTV

Ponticulus Posticus Latin, little posterior bridge Young et al., 2005 JBJS(A) 15.5% prevalence of arcuate foramen in 464 lateral c-spine x-rays

Ponticulus Posticus

Ponticulus Posticus

X-rays

Cervical X-rays ABCDEs A: adequacy, alignment B: bones C: cartilage D: disc space E: else (skull, clavicle) S: soft tissue

Lateral C-spine

Harris Lines SAC: > 13 mm

Powers’ Ratio BC/OA Limited Usefulness >1 considered abnormal Limited Usefulness Positive only in Anterior Translational injuries False Negative with pure distraction

Open-mouth View

Occipital Condyle Fractures CT, R/O OC dissociation I: comminuted, axial impaction Stable  Collar 6-8 weeks II: extension of basilar skull fracture into condyle Potentially unstable  Collar 6-8 weeks III: avulsion of alar lig Minimal displaced  Halo vest, 8-12 weeks Displaced  O-C2 fusion Consider surgery if OC dissociation

Occipito-cervical Dissociation Rare and usually fatal Often assoc. with facial injuries, chest trauma Deceleration AVOID traction!! Halo until surgery 1º treatment: Oc-C2 fusion if good screw purchase Oc-C3 fusion otherwise Biomechanically: plate & screw > screws > wires

Traynelis Classification of Occipito-cervical Dissociation

Harborview Classification of Occipitocervical Injury MRI: hemorrhage or edema at OC junction Normal Harris lines No distraction on traction test with 25 lb of traction II: < 25 lb traction: sufficient distraction to meet OC dissociation thresholds of Harris III: Static imaging: distraction beyond thresholds of Harris

Atlas (C1) Fractures 10% of all cervical fractures Rare neurological deficits; if any, R/O dissociation 50% concomitant fractures Morphological classification Posterior arch: hyperextension Lateral mass: rotation or lateral flexion forces Anterior arch fractures (blowout or plow fractures) : hyperextension, Bursting-type fractures (Jefferson): symmetrical axial load Transverse process Anterior tubercle

Atlas Fractures The extent of lateral mass separation is more relevant than the number of fracture fragments

Stable Atlas Fractures Posterior arch fracture: collar 10-12 weeks Anterior arch avulsion fracture: collar C1 ring fracture with <7 mm of overall lateral mass displacement: collar or halo

Unstable Atlas Fractures C1 ring fracture with ≥7 mm of overall C1 lateral mass displacement: prolonged halo or fusion (C1-C2, or Occiput-C2) Plough fracture: reduction with halo in slight flexion or C1-C2 fusion or occiput-C2

Plough Fracture

Rupture of Transverse Ligament Flexion force Dickman Classification: Mid-substance tear Avulsion of lateral mass of C1 As force increases, alar and apical lig tear (ADI > 7mm) Treatment: If ADI ≤5mm  collar If ADI >5mm and type I  C1-C2 fusion If ADI >5mm and type II  halo

Atlanto-Axial Instability A: Rotational Around the dens Treated with closed reduction and immobilization. Beware of associated fractures B: Translational Translation between C1–C2, where transverse lig is disrupted Mid-substance transverse ligament tears (type I) are treated with C1–C2 arthrodesis C: Distraction: Indicating craniocervical dissociation Bony avulsions (type II) may be treated with halo or C1–C2 arthrodesis

Rotatory Atlanto-Axial Instability C1-C2 Fusion Collar or Halo

Axis (C2) Fractures Odontoid fractures Traumatic spondylolisthesis of the axis (hangman's fracture)

Odontoid Fractures 60% of C2 fractures 10-20% of all c-spine fractures Neurological deficits in 10-20% Bimodal: young (high energy), elderly (falls) Anderson and D'Alonzo Classification

Type I Odontoid Occurs at tip, cephalad to the transverse Least common Represent an avulsion of the alar ligament Treated with collar or halo 6-8 weeks Surgery (occiput-C2 fusion) if associated with occipitocervical dissociation

Type III Odontoid Extends into the body of the axis More stable than type II fractures Higher union rate with non-surgical Treated with a halo or brace 8-12 weeks after reduction if displaced

Type II Odontoid At the junction of the base of the odontoid and body of the axis The most common fracture type The least likely to heal with non-surgical (10-77% non-union) IIA: new addition, comminution at base Treatment: controversial

Type II Odontoid Higher risk of non-union: Initial displacement > 5mm Posterior displacement Angulation > 100 Age > 50 Smoking Delay in diagnosis > 3 weeks Inability to achieve or maintain reduction

Options for High Risk type II Collar: very high risk of non-union Reduction and Halo: risk of complications in elderly Anterior Odontoid Screw(s) Pros: High union rate, preserves atlanto-axial motion Cons: Poor fixation in osteoporotic, difficult in large chest or posteriorly displaced C/I: reverse obliquity Posterior C1-C2 arthrodesis: C1-2 transarticular screw > segmental C1-2 fixation > wires techniques

Anterior Odontoid Screw

Traumatic spondylolisthesis of the Axis (Hangman's fracture) 2nd most common fracture of C2 15% of all cervical spine fractures Higher energy injury, associated spinal #: 30% Younger age group, MVC MOI: hyperextension + axial compression; additional flexion moment leads to very unstable injury Rare neurological involvement

Hangman's Fracture Effendi  Levine & Edwards Classification

Type I Hangman’s Most common Bilateral pars fractures with translation <3 mm and no angulation Treated with collar, occasionally halo

Type IA Hangman’s Atypical fracture, recently recognized Minimal translation and little or no angulation Elongation of the C2 body CT: extension of fracture line into the body and often through the foramen transversarium (vertebral artery injury may occur) May have canal compromise Usually halo, surgery if neuro deficits Surgical options: anterior C2–C3 arthrodesis, posterior C1–C3 vs C2–C3 arthrodesis, or combined approach

Type IA Hangman’s

Type II Hangman’s C2-3 disc and PLL are disrupted, resulting in translation >3 mm and marked angulation ALL generally remains intact but is stripped from its bony attachment Halo: after reduction in slight extension

Type IIA Hangman’s Less common; MOI: hyperext, axial then flex Fracture line is more oblique than vertical (vs II) Little or no translation, but significant angulation. Avoid traction Halo, and if markedly displaced, possibly direct fixation of fractured arch through a posterior approach C1-C3, or by C2–C3 anterior discectomy and arthrodesis

Type III Hangman’s A combination of pars fracture with dislocation of the C2-3 facet joints Very unstable, with free-floating inferior articular processes The most common injury to be associated with neurological deficit Requires surgery; it is irreducible by closed means Options: Anterior C2-3 discectomy and fusion, or posterior open reduction and C1-3 fusion

Posterior C1-2 Fusion Gallie Technique

Posterior C1-2 Fusion Brooks-Jenkins technique

C1–C2 Transarticular Screw Fixation Magerl technique

Finally.. It’s over!

Halo Crown first then the vest Prep areas in infiltrate with local Normally put scoop under head (unless contraindicated) Put halo crown around head Landmarks: for the anterolateral pins, 1cm above the lateral 1/3 of the eyebrow and the same distance above the top of the ear Place the anterior pins in bare skin NOT in the hairline

Halo Have patient close eyes before insertion of ant pins Place 4 pins in and tighten all 4 to engage skin and bone Tighten to 8 in-lb with the torque wrench Place the vest on X-ray!

Halo Care Routinely retighten after 24-48 hours If a pin is to be replaced, a new pin should be inserted satisfactorily before the loose pin is removed Pin sites should be cleaned daily Most commonly injured nerves are the supraorbital and supratrochlear

Halo Care Inserting anterolateral pins behind the hairline in hopes of obtaining a more cosmetically acceptable scar should be avoided - this location places the pin within the temporal fossa where the skull is the thinnest Pins located in the temporal fossa also pierce the temporalis muscle and often lead to painful mastication