Upper Cervical Trauma

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

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

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

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

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

6. Anatomy

7. Anatomy • Unique anatomy of O-C1-C2 • 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

8. Courtesy of AnatomyTV

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

16. Ponticulus Posticus

17. Ponticulus Posticus

18. X-rays

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

20. Lateral C-spine

21. Harris Lines SAC: > 13 mm

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

23. Open-mouth View

24. 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

25. 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

26. Traynelis Classification of Occipito-cervical Dissociation

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

28. 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

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

30. 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

31. 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

32. Plough Fracture

33. 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

34. 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

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

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

37. 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

39. 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

40. 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

41. 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

42. 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

43. 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

44. Anterior Odontoid Screw

45. 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

46. Hangman's FractureEffendi  Levine & Edwards Classification

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

48. 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

49. Type IA Hangman’s

50. 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