1. Identification of Spinal Ligamentous Injuries in Trauma
Andrew J Seier, MS3

2. Background Orthopedics often called upon to “clear the C-spine”
Clinical exam (NEXUS, Canadian C-Spine Rule), plain films, CT
Possibility of purely ligamentous injuries not detectable on plain films or CT
What to do if there is cervical pain/tenderness, neurological findings, or the patient is obtunded, in the setting of a negative CT?

3. Ligamentous Injuries Visible on MRI
Spinal Cord Injury Without Radiologic Abnormality
PLL, ALL, SSL, ISL, LF, facet joint capsules
3-column model: injuries to all 3 columns an absolute indicator of instability
Erwood A, Abel T, Grossbach A, Ahmed R, Dandaleh N, Dlouhy B. Acutely unstable cervical spine injury with normal CT scan findings: MRI detects ligamentous injury. JOURNAL OF CLINICAL NEUROSCIENCE. 2016;24:

4. Guidelines ATLS handbook: EAST: UpToDate
“if CT films are truly normal, significant instability is unlikely. Patients with neck pain and normal films may be evaluated by magnetic resonance imaging (MRI) or flexion- extension x-ray films, or treated with a semi-rigid cervical collar for 2–3 weeks”
EAST:
“It is not clear, however, if all injuries that are identified by MRI CS are clinically significant … MRI CS should only be used to clear the CS in the obtunded patient after a CT CS has cleared the CS of any bony abnormality … At present, we cannot make a definitive recommendation on the need for MRI CS after a negative CT CS in the obtunded patient with blunt trauma.”
UpToDate
“severe neck pain, persistent midline tenderness, upper extremity paresthesias, or focal neurologic findings” in an alert patient with negative CT calls for MRI
Obtunded patients, unclear evidence

5. 11 studies met inclusion criteria, comprising 1550 patients who underwent MRI after a negative CT for blunt trauma
182 positive MRIs, 96 of which changed management (84 continued immobilization, 12 surgeries)
All patients were obtunded, 6 of 11 studies included were retrospective
Conclusion: Recommend MRI in obtunded blunt trauma patients with negative CT

6. Single-center retrospective analysis of 1004 patients from 2004- 2011
MDCT interpreted as “without evidence of acute traumatic injury”
Cervical MRI during the same hospital admission
GCS distribution: 537 (15-13), 335 (13-9), 132 (8-3)
Indications for MRI: neck pain, AMS, neurological signs
Limitation: 82% had no follow-up
Conclusion: MRI adds little to MDCT findings. Ligamentous injuries found on MRI were not unstable

7. Prospective, multi-center trial of 767 patients
Indications for MRI: cervicalgia (43%), unevaluable (44%), or both (9%)
No significant difference amongst subgroups: cervicalgia vs unevaluable, neuro sx vs no neuro sx
157 patients were kept immobilized, 11 underwent surgery
Limitations: different threshold for MRI at different centers, possibility of observer bias in immobilization
Conclusion: Additional injuries were found, but clinical significance is unclear

8. Conclusions
Literature supports MRI in alert patients with neurological signs or cervicalgia in the setting of a negative CT
In obtunded patients, data is less clear
Practical limitations and risks in ordering MRI for obtunded patients
Risks vs benefits for imaging
Improving quality of MDCT
Sensitivity and specificity of MDCT is very high (~99.6%), purely ligamentous injuries found only on MRI are rare and most are not clinically significant