Identification of Spinal Ligamentous Injuries in Trauma

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;24:165-165.

4. Guidelines • ATLS handbook: • “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