Does Cognitive Status Affect Spinal Surgery Outcomes: A Systematic Review and Meta-Analysis

Introduction: Mild cognitive impairment (MCI) and Dementia have been shown to be independent risk factors for complications after spine surgery. To date, no systematic review has been conducted on the effect of cognitive impairment (CI) on spine surgery outcomes. With this, this study aims to perform a systematic review and meta-analysis of previous studies on perioperative outcomes and facility-based measures in cognitively impaired patients undergoing spine surgery.

Methods: A systematic search of PubMed, Embase, Cochrane Library, and Web of Science was conducted on July 8th, 2024. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies directly comparing spine surgery outcomes in cognitively impaired populations versus normal cognition were included for meta-analysis. Studies discovering cognitive impairment as a risk factor secondarily associated with an analyzed variable were included for review only. Data on postoperative outcomes including delirium, urinary tract infection (UTI), myocardial infarction, ileus, pulmonary embolism (PE), deep vein thrombosis (DVT), pneumonia, surgical site infection (SSI), wound dehiscence, sepsis, acute kidney injury, neurological complications, reoperation, readmission, intensive care unit admission, length of stay, discharge location, and cost were assessed. Lumbar and cervical sub-group analyses were also conducted.

Results: A total of 1074 articles were screened as titles and abstracts. 66 studies were included for full-text review, yielding 31 articles to be included in this study. 13 studies (8 retrospective cohort studies, 5 prospective observational studies) directly analyzed the effect of CI on spine surgery outcomes. Random-effect model demonstrated patients with CI were found to have significantly higher odds of developing UTI (OR 4.32{2.24-8.33}), delirium (OR 2.51{1.69-3.72}), DVT (OR 2.49{1.23-5.03}) pneumonia (OR 3.24{1.94-5,43}), wound dehiscence (OR 1.50{1.08-2.08}), sepsis (OR 2.18{1.04-4.56}) ICU admission (OR 2.05{1.22-3.44}), home discharge (OR 0.29{0.26-0.32}), and readmission (OR 1.22{1.07-1.39}) after spine surgery.

Conclusion : This study suggests that preoperative CI is associated with worse postoperative health outcomes and inferior facility-based measures in spine surgery patients. These findings highlight the importance of early recognition and management of cognitive impairment prior to spine surgery, as doing so may mitigate postoperative risks and improve both clinical and facility-based outcomes.