Background: Cervical spine injuries (CSI) are often challenging to diagnose in obtunded adult patients with blunt trauma and the optimal imaging modality remains uncertain. This study systematically synthesized the last decade of evidence to determine the type of imaging required to clear the c-spine in obtunded patients with blunt trauma.

Methods: A systematic review with meta-analysis was conducted and reported using PRISMA 2020 guidelines. The protocol was registered on June 22, 2022 (PROSPERO CRD42022341386). MEDLINE (Ovid), EMBASE, and Cochrane Library were searched for studies published between January 1, 2012, and October 17, 2023. Studies comparing CT alone to CT combined with MRI for c-spine clearance were included. Two independent reviewers screened articles for eligibility in duplicate. Meta-analysis was conducted using a random-effect model. Risk of bias and quality assessment were performed using the ROBINS-I and QUADAS-2. The certainty of evidence was assessed using the GRADE methodology.

Results: 744 obtunded trauma patients from six included studies were included. Among the 584 that had a negative CT scan, the pooled missed rate of clinically significant CSI using CT scans alone was 6 % (95 % CI: 0.02 to 0.17), and the pooled missed rate of CSI requiring treatment was 7 % (95 % CI: 0.02 to 0.18). High heterogeneity was observed among included studies (I² > 84 %). The overall risk of bias was moderate, and the quality of evidence was low due to the retrospective nature of the included studies and high heterogeneity.

Conclusions: Limited evidence published in the last decade found that CT scans alone may not be sufficient for detecting clinically significant CSI and injuries requiring treatment in obtunded adult patients with blunt trauma.

Implications of key findings: Clinicians should be aware of the limitations of CT scans and consider using MRI when appropriate. Future research should focus on prospective studies with standardized outcome measures and uniform reporting.