Emergency radiology: straightening of the cervical spine in MDCT after trauma--a sign of injury or normal variant?

OBJECTIVE: To evaluate whether straightening of the cervical spine (C-spine) alignment after trauma can be considered a significant multidetector CT (MDCT) finding.

METHODS: 160 consecutive patients after C-spine trauma admitted to a Level 1 trauma centre received MDCT according to Canadian Cervical Spine Rule and National Emergency X-Radiography Utilization Study indication rule; subgroups with and without cervical collar immobilization (CCI +/-) were compared with a control group (n = 20) of non-traumatized patients. Two independent readers evaluated retrospectively the alignment, determined the absolute rotational angle of the posterior surface of C2 and C7 (ARA C2-7) and grouped the results for lordosis (<-13°), straight (-13 to +6°) and kyphosis (>+6°).

RESULTS: In the two CCI-/CCI+ study groups, the straight or kyphotic alignment significantly (p = 0.001) predominated over lordosis. The number of patients with straight C-spine alignment was higher in the CCI+ group (CCI+ 69% vs CCI- 49%, p = 0.05). A comparison of the CCI+ group vs the CCI- group revealed a slightly smaller number of kyphotic (10% vs 18%, p = 0.34) and lordotic (21% vs 33%, p = 0.33) alignments. Statistically, however, the differences were of no significance. The control group revealed no significant differences.

CONCLUSION: Straightening of the C-spine alone is not a definitive sign of injury but is a biomechanical variation due to CCI and neck positioning during MDCT or active patient control.

ADVANCES IN KNOWLEDGE: Straightening of the C-spine alignment in MDCT alone is not a definitive sign of injury. Straightening of the C-spine alignment is related to neck positioning and active patient control. CCI has a straightening effect on the cervical alignment.