Volume 5, Case 5
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaiʻi John A. Burns School of Medicine
Test your skill in reading these 16 pediatric cervical spine radiographs. Many of these have subtle findings. Follow the principles outlined in Case 2 of this volume, Cervical Spine Radiographs, and see how accurate you can be at interpreting these radiographs.
View Case A
Interpretation of Case A
Lateral and AP views are shown here. The top of the lateral view was cut off, thus visualizing only part of C1. There is an obvious compression fracture of C5. C4 and C7 are also compressed. There is an avulsion of the anterior superior lip of C7.
The AP view shows a vertical fracture through C5.
Impression: Compression fractures of C4, C5, C7.
View Case B
Interpretation of Case B
Two lateral views are shown here. Both radiographs show that C4 is displaced anteriorly with respect to C5. The anterior vertebral body line, the posterior vertebral body (anterior spinal canal) line, and the spinolaminal (posterior spinal canal) line are out of alignment.
Impression: C4-C5 subluxation.
View Case C
Radiographs contributed by Martin I. Herman, MD
Interpretation of Case C
This lateral view shows C4 slightly displaced anteriorly with respect to C5. Someone has placed a strip of tape over the arch of C5 to show that the posterior border of the C5 vertebral body does not line up with the other vertebral bodies. The borders of the tape introduce some artifact. The lucency that appears over the arch of C6 is from the tape (not a fracture).
The anterior vertebral body line, the posterior vertebral body (anterior spinal canal) line, and the spinolaminal (posterior spinal canal) line are out of alignment.
Impression: C4-C5 subluxation.
View Case D
Radiographs contributed by Martin I. Herman, MD
Interpretation of Case D
This lateral view shows C2 tilted anteriorly over C3. While one might consider the possibility that this is a C2-C3 pseudosubluxation, this degree of angulation is excessive. Additionally, the C2-C3 facet joints are disrupted.
Radiographic features consistent with a C2-C3 pseudosubluxation are:
1) Neck position should be neutral or in flexion. However, in the case of this radiograph, the lower portion of the neck (C3 to C7) is in extension (lordosis). The only flexion in the neck is at the C2-C3 region, which is abnormal. Since this criterion is not met, this is not consistent with a pseudosubluxation.
2) The Swischuk line should be in good alignment. This is a line drawn from the anterior aspect of the posterior arch of C1 to the anterior aspect of the posterior arch of C3. The anterior aspect of the posterior arch of C2 should be within 1.5 mm of this line (refer to Case 3 of this volume and Case 5 of Volume 1). In the case of this radiograph, the Swischuk line alignment is satisfactory.
3) Other factors favoring a pseudosubluxation include a benign mechanism of injury, low clinical risk, and resolution of the pseudosubluxation upon repeating the radiograph following repositioning the neck in extension (lordosis) (This often cannot be done if a true subluxation is suspected).
Thus, a satisfactory alignment of the Swischuk line alone is not sufficient to rule out a true subluxation.
The anterior vertebral body line, the posterior vertebral body (anterior spinal canal) line, and the spinolaminal (posterior spinal canal) line are out of alignment.
Impression: C2-C3 subluxation.
View Case E
Interpretation of Case E
This lateral view shows C2 slightly displaced anteriorly with respect to C3. The anterior vertebral body line, the posterior vertebral body (anterior spinal canal) line, and the spinolaminal (posterior spinal canal) line, are out of alignment. This radiograph shows poor positioning. It is not a true lateral, rather it is oblique. Note the prominence of the intervertebral foramina which are most prominent on an oblique view.
Unlike case D, this radiograph shows the entire cervical spine to be in flexion. The Swischuk line is at the limits of tolerance in this case since the anterior aspect of the posterior arch of C2 is about 1.5 mm from the Swischuk line; however it is not a true lateral view.
Clinically, this patient's mechanism of injury is low risk and her degree of discomfort is felt to be most consistent with a pseudosubluxation. Repeat films of her neck in better positioning are normal.
Impression: Probable C2-C3 pseudosubluxation.
The anterior vertebral body line, the posterior vertebral body (anterior spinal canal) line, and the spinolaminal (posterior spinal canal) line, are out of alignment probably due to poor positioning.
View Case F
Radiographs contributed by Collin S. Goto, MD
Interpretation of Case F
This is an 18-month old male riding unrestrained in the front passenger seat of a car involved in a motor vehicle collision. He was ejected from the vehicle, sustaining multiple trauma.
Lateral and AP views are shown here. The lateral view shows separation of the skull from the cervical spine (atlanto-occipital dislocation).
NOTE: There is a visible lucency at the base of the odontoid. This is the subdental synchondrosis, a normal finding in young children. This synchondrosis generally fuses by age 3 to 6 years.
Impression: Atlanto-occipital dislocation.
View Case G
Radiographs contributed by Collin S. Goto, MD
Interpretation of Case G
This is a 5-year old female who fell off a trampoline onto her head with her neck flexed. She presented to the E.D. with neck pain and tingling in her feet.
Two lateral views are shown here. The anterior vertebral body line, the posterior vertebral body (anterior spinal canal) line, and the spinolaminal (posterior spinal canal) line, are out of alignment. C3 is displaced anteriorly with respect to C4. The facet joints of C3/C4 are out of alignment. There is possible facet joint subluxation at C2/C3.
Impression: C3-C4 subluxation.
View Case H
Interpretation of Case H
A lateral view is shown here. The pre-vertebral soft tissue space is widened suggesting the possibility of hemorrhage into this area from a fracture. An NG tube is in place. An NG tube in the esophagus could widen the pre-vertebral soft tissue space as well. In this instance, it is not certain if the widening of the pre-vertebral soft tissue space is pathologic.
The anterior vertebral body line, the spinolaminal (posterior spinal canal) line, and the spinous processes tips line are all in satisfactory alignment. The posterior vertebral body line is slightly disrupted at the C6-C7 junction where C6 appears to be displaced slightly anterior with respect to C7 (difficult to see). The anterior vertebral body line may also be slightly disrupted at C6-C7, however, this is so slight that it is difficult to be certain. There is a possible irregularity of the posterior inferior corner of the C6 vertebral body. This is possibly a small avulsion fracture. The facets of C6 are displaced slightly anteriorly with respect to the facets of C7.
Impression: Possible small avulsion fracture of the posterior inferior corner of the C6 vertebral body. Possible anterior displacement of the C6 with respect to C7. These abnormalities are not definite. The study is possibly normal.
View Case I
Interpretation of Case I
Two lateral views and a single AP view are shown here. The lateral view on the right shows an obvious fracture of the odontoid. However, note that on the other lateral view of the same patient, the odontoid fracture is not as easy to appreciate. In the lateral view on the left, the odontoid fracture can be identified by the angulation of the odontoid. The other bony elements are normal. Alignment is satisfactory otherwise.
NOTE: The fracture at the base of the odontoid could possibly be confused with the normal lucency at the base of the odontoid in young children (the subdental synchondrosis). However, while it may be normal for the odontoid to tilt backward (posteriorly), it should NOT be tilting forward (anteriorly). Anterior tilting of the odontoid with a widening of the lucency at the base of the odontoid are highly indicative of a fracture and not a normal synchondrosis.
Impression: Odontoid fracture.
View Case J
Interpretation of Case J
Lateral, AP, and odontoid views are shown here. C7 is not visualized well on the lateral view, making this study inadequate. On the lateral view, C2 may be slightly displaced anteriorly with respect to C3. The anterior vertebral body line identifies this displacement best. The posterior vertebral body (anterior spinal canal) line, and the spinolaminal (posterior spinal canal) line, are within satisfactory alignment. The lateral view also shows an irregularity of the anterior inferior corner of the C2 vertebral body. This can only be seen on the enlarged view. It resembles a small drop dripping from the vertebral body (difficult to see). This is a small avulsion fracture. The pre-vertebral soft tissue space is within normal limits.
The AP view shows good alignment of the spinous processes and equal spacing. The odontoid view shows the lateral masses of C1 well-positioned with respect to C2.
Impression: Small avulsion fracture of the anterior inferior corner of the C2 vertebral body. Slight anterior displacement of C2 with respect to C3.
View Case K
Interpretation of Case K
There is a fracture of the spinous process of C7. The anterior and posterior vertebral body lines are satisfactory. The spinolaminal line is satisfactory. The tips of the spinous processes are difficult to see with the exception of C7, which is fractured.
This radiograph demonstrates a modest degree of "fanning". Normally, the spinous processes are evenly spaced and they converge toward a point because of their attachment by the posterior longitudinal ligament and the interspinous ligament. However, this radiograph shows that the spinous process of C7 is not converging toward the same point as the other spinous processes. This spreading of the spinous processes, known as fanning, is consistent with a fracture of the spinous process or a tear of the posterior longitudinal ligament.
This has the appearance of a typical "clay shoveller's" fracture, which generally occurs when the neck is forced forward (flexed) while it is held in extension (lordosis). In this case, this teenager was swimming when someone diving from the rocks above, fell onto his back.
Impression: C7 spinous process fracture.
View Case L
Interpretation of Case L
Several views are shown here. The upper left image is a lateral view which only shows C1 to the upper portion of C5. Two oblique views are shown in the upper right. The lower left image is an AP view. The right lower image shows two swimmer's views.
The lateral view show no pre-vertebral soft tissue widening. C1 to the top of C5 are in satisfactory alignment. The swimmer's views show poor images of C5 and C6. C7 is still not well visualized. The anterior portion of the C6 vertebral body is slightly shorter than the posterior portion, indicating the possible presence of a compression fracture. While the height of C6 seen on the AP and oblique views may seem slightly short, it is probably within normal limits.
Impression: Possible compression fracture of the anterior portion of the C6 vertebral body. C7 is not visualized well.
View Case M
Interpretation of Case M
Multiple views are shown here. The upper left image is the lateral view. The upper right image is an odontoid view with the AP view beneath it. The lower left images are oblique views. The lower right image is a swimmer's view.
The lateral view shows C1 to the upper portion of C6. C7 is not visualized. C4 and C5 show compression fractures of the anterior portions of the C4 and C5 vertebral bodies. C3 appears to be slightly displaced anteriorly with respect to C4 on both the lateral view and the swimmer's view.
C2 appears to be slightly displaced anteriorly with respect to C3. This is due to kyphosis secondary to the fractures.
The odontoid view shows the odontoid well centered within C1. However the lateral margins of the lateral masses cannot be determined from this odontoid view. Thus, this particular odontoid view is not of satisfactory quality.
There are no identifiable abnormalities on the oblique views. The swimmer's view shows C6 better, but C7 is still not visualized, making this study suboptimal.
Impression: Compression fractures of C4 and C5. Unable to visualize C7.
View Case N
Interpretation of Case N
A lateral view is shown here with the neck in a flexed position. C2 is out of alignment anteriorly with respect to C3. There is a lucency through the base of the odontoid. There is widening of the pre-vertebral soft tissue. The Swischuk line is in satisfactory alignment.
All of these findings are consistent with a pseudosubluxation due to the positioning of the neck in flexion. This film was repeated with a better lordotic extension of the neck. Both the C2-C3 pseudosubluxation and the pre-vertebral soft tissue widening resolved.
Impression: Pseudosubluxation. Normal subdental synchondrosis.
View Case O
Interpretation of Case O
There is fusion of several vertebral units. Alignment appears to be satisfactory, but normal anatomic landmarks are not present.
Impression: Congenital fusion of adjacent vertebral bodies.
View Case P
Interpretation of Case P
C4 and C5 are out of alignment, displaced posteriorly with respect to the rest of the C-spine. The anterior aspects of the C4 and C5 vertebral bodies are shorter than the posterior aspects due to wedge type compression fractures. The vertebral body of C6 is shortened due to a compression fracture.
Impression: Wedge type compression fractures of C4 and C5. Compression fracture of C6. Posterior subluxation of C5 on C6.