1. Imaging the Traumatized Patient MI Zucker, MD
The CERVICAL SPINE
Imaging the Traumatized Patient
MI Zucker, MD

2. A dr Z Lecture …on imaging cervical spine trauma.
With much gratitude to Jack Harris, MD.

3. Michael I. Zucker, MD Professor, Dept. of Radiology
Faculty, Dept. of Emergency Medicine
UCLA Medical Center, David Geffen School of Medicine at UCLA

4. 10,000 spinal cord injuries per year in USA
Two-thirds are cervical cord.
The monetary, physical and emotional losses are great.
Our goal: Early detection of injuries to prevent or decrease neurological and mechanical damage to the spinal column.

5. STABILITY: A Word or Two
We talk about it, but what is it?
A useful definition: An injury is STABLE if putting the spinal column through normal range of motion does not increase neurological or mechanical deficits.

6. Three Column Theory of Denis
Spinal column divided into an ANTERIOR, MIDDLE and POSTERIOR column.
Injury to one column is stable, two or three are unstable.

7. ANTERIOR COLUMN
The anterior longitudinal ligament, anterior 2/3 of the body and disc.

8. MIDDLE COLUMN
Posterior longitudinal ligament and posterior 1/3 of body and disc.

9. POSTERIOR COLUMN
The posterior osseous arch and ligaments.

10. DOES IT WORK?
If two or three columns injured, lesion is unstable: Works well for C3 to T1.
Does not work so well for C1-2, so consider most or all injuries here unstable.

11. HOW DO YOU IMAGE THE CERVICAL SPINE?
Plain films?
CT?
MRI?
A combination of modalities?
Is there a consensus?

12. (But we’re headed toward one)NO
(But we’re headed toward one)

13. My Opinion:
O*pin*ion: A belief held with confidence, but not substantiated by proof.

14. Imaging Minor Trauma
LATERAL view from skull base through at least the top one-half of T1. May need to supplement with Swimmer’s view.
Anterior-posterior (AP)
Open Mouth Odontoid (OMO)
If patient is not in cervical collar: Adding Oblique views is an option.

15. MINOR TRAUMA: Views

16. Imaging Major Blunt Trauma
Cross-table LATERAL plain film in Trauma Suite.
CT entire cervical spine.
MRI also in selected cases.
If you wish, AP, OMO, and Swimmer’s views also -- IF they DO NOT cause delay.
CT: Axial sections base of skull through T1- AND- Sagittal (like a lateral) and Coronal (like AP and OMO) reformatting.

17. MAJOR TRAUMA: Imaging Cross-table Lateral in Trauma Suite
CT Base of skull through T1

18. Swimmer’s View in Major Trauma
A SUPPLEMENTARY view to see C7-T1 in lateral projection. NOT a substitute for a bad lateral. One arm must be elevated, so THEORETICALLY could worsen a mechanical or neurological injury.
A state-of-the-art CT sagittal reformat is preferable: don’t need to move patient and imaging easier and better.

19. CT Axial sections from base of skull through T1.
ALWAYS do the ENTIRE cervical spine.
DON’T do selective imaging with modern scanners.

20. CT: Sagittal Reformatting
Reconstructed by computer from axial data: no additional imaging needed.
Outstanding “lateral/swimmer’s” imaging.

21. CT: Coronal Reformatting
Excellent “OMO”
Excellent “AP”

22. MRI Gold standard for cord, thecal sac, nerve root and disc injuries.
Very good for ligament injuries.
Fairly good for fractures, but does miss some. CT much better.

23. NEUROLOGIC DEFICIT
In my view, ANY neurologic deficit, extant or transient, is MAJOR trauma, and will need CT followed by MRI.

24. Any abnormality on Plain Films or worrisome examination: do CT!
Remember: Fractures often come in 2’s and 3’s. The more serious injury may be the one that is occult.

25. ARE THERE RISKS?
Ionizing radiation can damage cells. Younger people are more susceptible than older people. Their cells are more sensitive and they have longer to manifest somatic or genetic damage.
The radiation dose is significantly higher in CT than in plain films.
As in most decisions in medicine, one must weigh the risks versus the benefits.

26. My Approach to Success in Image Interpretation
Know what to order.
Know what an optimal imaging series is and don’t accept less.
Read by check list.
Know the common lesions.
Know the commonly MISSED lesions.

27. Remember: The lesions are the SAME regardless of the imaging modality
Plain films are still the most common modality.
If you learn on them, you can translate your knowledge to CT and MRI.

28. PLAIN FILM Series LATERAL ANTERIOR-POSTERIOR (AP)
OPEN MOUTH ODONTOID (OMO)
*REVERSE WATERS
*SWIMMER’S
*OBLIQUES

29. THE CHECK LIST
View by view

30. LATERAL view
This is your MAIN view where 90% of injuries are detected.
You MUST see T1. If not seen, do Swimmer’s view, unless not safe to do so.
You did lateral and Swimmer’s and still no luck? DON’T QUIT: DO CT! Once you start an exam you must complete it.

31. LATERAL View: First Survey
Look for gross fracture or dislocation.
Count vertebrae.
Look at skull, entire airway and adjacent soft tissues.

32. LATERAL View: Prevertebral Soft Tissues
Contour is more important than measurements: straight or concave anteriorly, except at larynx.
Top normal limits: C2 6mm; C6 22mm for adult, 14mm for young child.

33. LATERAL View: Alignment
Anterior body line.
Posterior body line.
Spino-laminar line (called posterior cervical line at C1-3).

34. LATERAL View: Alignment
Turning the lateral view HORIZONTALLY can help detect subtle malalignment.

35. LATERAL View: Spaces Disc spaces: too wide, too narrow, not uniform?
Facet joints: too wide, not uniform?
Interspinous distances: too wide, too narrow, not uniform?

36. LATERAL View: C1 and C2
Basion-dens distance: average 8mm, top normal 12mm.
C1: Anterior and posterior arch.
C2: Dens, Harris’ ring, body especially ant/inf corner, pars and posterior arch.

37. LATERAL VIEW: Predental Space
In an adult, upper normal is 2.5mm. Space is parallel or narrow “V” shape.
In a young child, upper normal is 4.5mm.

38. LATERAL VIEW: Predental Space

39. LATERAL View: C3-T1
Body: loss of straight or concave anterior contour, loss of height?
Posterior arch: subtle cortical irregularity, overt fracture line?

40. LATERAL VIEW: Child Vertebral bodies are bullet shaped.
Physiologic pseudosubluxations are common, especially C2-4.
Predental space is wider.
Lymphoid tissue makes soft tissues more prominent.

41. SWIMMER’S View A supplemental view to see C7-T1.
Must raise one arm. Probably not a good idea if neurologic deficit, altered level of consciousness, upper arm injury. Could worsen an injury.

42. ANTERIOR-POSTERIOR View
Look at first few ribs, sterno-clavicle junction, lung apices.
Contour of lateral margins of lateral masses.
Uncovertebral joints.
Alignment and contour of spinous processes.
Position and contour of trachea.

43. The ODONTOID Views Open Mouth Odontoid (OMO) is main view.
Reverse Waters view is supplementary, to see top half of dens ONLY.

44. OMO C1-2 lateral mass alignment of lateral margins.
Dens: cortical margin irregularities, fracture lines, tilt.
Upper body of C2 for fracture lines.
Mach lines can be confusing.

45. The INJURIES C1 and C2: by anatomic location
C3 to T1: by mechanism of injury
(Modified from the classification of John Harris, et al.)

46. The Atlas and the Axis
C1 and C2 injuries differ from the rest of the cervical spine and are considered separately.
Although controversial, best to consider ALL C1 and C2 injuries as UNSTABLE in the acute trauma setting.

47. Occipital-atlantic Injuries
Occipital condyle fractures: lateral bending, uncommon, seen only on CT.
Occipital-atlantic dissociation (OAD): rare distraction injury, usually fatal. Basion-dens distance is abnormal, 12+mm.

48. The ATLAS: C1 Anterior arch fracture: extension, uncommon.
Posterior arch fracture: extension, more common.
JEFFERSON fracture: axial load, common

49. C1: Isolated Arch Fractures
Anterior arch
Posterior arch
CAUTION: You may be dealing with a Jefferson fracture with occult components: Best to CT all C1 fractures.

50. JEFFERSON Fracture: C1 Axial load (“burst”) injury
Pure (4) or variant (2 or 3) fractures, involving both ant. & post. arches of C1
Cord injury in 15%
Lateral view: anterior and posterior arch fractures
OMO view: lateral displacement of C1 lateral masses

51. JEFFERSON Fracture: C1
The lateral masses of C1 and C2 must be aligned on the OMO view.
1-2mm of lateral displacement on one side and an EQUAL medial displacement on the other is head rotation.
ANY other pattern: lateral displacement on both sides or lateral on one side, and none on the other is abnormal.

52. JEFFERSON Fracture CT Classical Jefferson: 4 fractures, 2 ant./2 post.
Jefferson variants: 2 or 3 fractures, but at least 1 ant. & 1 post.

53. The AXIS: C2 Dens fractures Pars fractures
Extension teardrop fractures

54. DENS Fractures Type I: alar ligament avulsion of the tip; rare.
Type II: the dens excluding the tip; 2/3.
Type III: high C2 body; 1/3.
Mechanism of Type II and III is controversial.

55. TYPE II Dens Fracture
Interrupted cortical margin, lucent fracture line, tilt especially anterior
Cord injury in 15%
Delayed or non-union 50+%

56. TYPE II Dens Fracture
CT axial

57. TYPE III Dens Fracture
Interrupted Harris ring, fat C2, lucent fracture line, tilt especially ant.
Cord injury in 15%
Heals well.

58. C2: PARS Fracture Called Hangman’s or pedicle fracture, both wrong.
Extension injury.
Cord injury in 15%.
Non-displaced, displaced, subluxed.

59. C2: Extension Teardrop Fracture
Avulsion by the anterior longitudinal ligament of the anterior-inferior corner of the body.
Extension mechanism.
Cord injury is low.

60. C3 to T1
These levels are so similar they will be considered as a unit.
The injuries are grouped by mechanism into “families”.

61. Flexion Flexion-rotation Extension Axial loading
The “FAMILIES”
Flexion
Flexion-rotation
Extension
Axial loading

62. “FAMILY FLEXION” Motto: “Anterior impaction, posterior distraction.”
Family members:
Wedge compression fracture
Hyperflexion sprain
Bilateral interfacetal dislocation
Hyperflexion teardrop fracture-dislocation
Spinous process fracture

63. Wedge Compression Fracture
Anterior-superior margin of the body is fractured.
If loss of height less than 50%, one column injury and so stable.
If height loss greater than 50%, posterior ligaments presumed torn and so 3 column unstable injury.
If 3 bodies fractured, unstable even if less than 50% height loss each.

64. Hyperflexion Sprain
Tear of the posterior (stable), posterior/ middle (unstable) and posterior/ middle/ anterior (unstable) ligaments without fracture.
One column stable, 2 or 3 unstable.
Delay in healing with eventual surgical fusion fairly common.
Can be a difficult diagnosis.

65. Flexion-Extension Films
May be helpful in ligament injuries
-but are-
Frequently useless due to muscle spasm

66. Flexion-Extension films
Rules: Patient must be alert, awake, not intoxicated, able to sit or stand, able to understand commands, and without neurologic deficit.

67. It is an Active, patient-generated STRESS TEST
NEVER “help” the patient to “improve” ROM.
NEVER do passive ROM: this is a neurosurgical procedure done under fluoroscopic control and is controversial.

68. MRI Gold Standard for spinal canal, cord, disc lesions.
Silver Standard for ligament injuries, but there is no Gold and much better than plain films, CT, and flexion/extension.

69. Bilateral Interfacetal Dislocation
BID, also called “locked facets” is anything but locked. It is a severe 3 column injury that is completely unstable.
Cord is injured in 2/3.
Body is subluxed anteriorly at least 50%.
Marked posterior distraction.

70. Hyperflexion Teardrop Fracture- dislocation
Among the worst survivable injuries, with nearly 100% severe cord lesion.
Completely unstable.
Little chance of neurologic improvement.

71. Hyperflexion Teardrop Fracture-dislocation
CT Sagittal Reformat

72. Spinous Process Fracture
The “clay shoveler’s fracture”.
Usually flexion, but can be extension or direct blow.
Stable if isolated, but do CT to look for associated posterior arch fractures.

73. Spinous Process Fracture
CT Sagittal Reformat

74. FLEXION-ROTATION Injuries
Unilateral Interfacetal Dislocation and Fracture-dislocation

75. Unilateral Interfacetal Dislocation
UID is not stable, as the contralateral capsule ligaments are torn.
Cord injury is uncommon, but root injury is common, and HNP also occurs.
Findings can be subtle: less than 50% subluxation, malalignment of spinous processes.

76. CT: This is a normal facet joint, normal “hamburger sign”

77. UID CT: UID has “reversed hamburger sign” of facet joint.
CT is also more sensitive for associated lateral mass fractures.

78. UID
Oblique view
CT Sagittal Reformat

79. EXTENSION Injuries Family motto: “Anterior distraction, posterior impaction.”
Posterior arch fractures
Extension teardrop fractures
Extension fracture-dislocations

80. Posterior Arch Fractures
Plain films are insensitive, CT is outstanding.
Isolated: pedicle, lateral mass, lamina or spinous process.
Multiple fractures are common. Pedicle/lamina fractures cause free-floating lateral mass.
May be additional element of lateral bending.
Stability depends on what is fractured.

81. Extension Teardrop Fracture
Avulsion fracture caused by anterior longitudinal ligament.
Vertical narrow fracture of anterior-inferior corner of body.
Most common site is C2.
Unstable.

82. EXTENSION Fracture- dislocation
More severe force fractures the body along end plate and causes subluxation, usually posterior.
Fracture is oriented longitudinally, and there is malalignment of the bodies.

83. AXIAL Loading “Burst” fractures explode the body.
All are very unstable and cause cord injury in 2/3 (except C1).
There is usually an element of flexion also.

84. BURST Fractures
On lateral, body is compressed anteriorly, inferior end plate often fractured, posterior body contour is convex.
On AP, body fracture is vertical or oblique and pedicles spread.

85. BURST Fractures
CT more accurately displays the fracture pattern and the very important degree of narrowing of the spinal canal.

86. REMEMBER: CT is much more sensitive for fractures than plain films.
MRI is the standard for soft tissue injuries.

87. GOODBYE AND GOOD IMAGING!
Copyright 2004
M. I. Zucker