Rate and Characteristics of Vertebral Artery Injury Following C1-C2 Posterior Cervical Fusion: A Systematic Review and Meta-Analysis.

ABSTRACT Introduction Intra-operative vascular injuries in the cervical spine are rare, but carry significant morbidity and mortality when they do occur. There is a need to better characterize the risk of vertebral artery injury after posterior C1-C2 fusion. Objective To investigate the rate of the vertebral artery injury for patients undergoing posterior C1-C2 cervical fusion. Methods An electronic database search was performed to identify studies that reported rates of vertebral artery injury following posterior cervical fusion at the C1-C2 level. Patient-specific risk factors, surgical indication, surgical technique and others were collected for each study. Forest plots were created to outline the pooled ratios of vertebral artery injury in the literature. Results A total of 11 studies with 773 patients were identified. The mean age of subjects was 48.47 years (range 6 to 78 years) and the majority of patients were females (61.7 %, n = 399). Trauma was the most frequent indication for surgery (18.8%, n = 146), followed by inflammatory processes affecting the vertebrae (13.2%, n = 102). The rate of vertebral artery injury per patient was 2% [95%CI: 1%-4%] among 773 patients, while per screw rate was 1% [95%CI: 0%- 2%] for a total of 2238 screws placed. Conclusion The rate of vertebral artery injury after C1-C2 posterior cervical fusion was found to be 2% for each operated patient and 1% for each screw placed.