The Effect of Diabetes on Complications After Spinal Fusion: A Systematic Review and Meta-Analysis

Objective Spinal fusion procedures are used to treat a wide variety of spinal pathologies. Diabetes mellitus (DM) has been shown to be a significant risk factor for several complications following these procedures in previous studies. To the authors’ knowledge, this is the first systematic review and meta-analysis elucidating the relationship between DM and complications occurring after spinal fusion procedures. Methods Systematic literature searches of PubMed and EMBASE were performed from their inception to October 1, 2022, to identify studies that directly compared postfusion complications in patients with and without DM. Studies met the prespecified inclusion criteria if they reported the following data for patients with and without DM: (1) demographics; (2) postspinal fusion complication rates; and (3) postoperative clinical outcomes. The included studies were then pooled and analyzed. Results Twenty-eight studies, with a cumulative total of 18,853 patients (2,695 diabetic patients), were identified that met the inclusion criteria. Analysis showed that diabetic patients had significantly higher rates of total number of postoperative complications (odds ratio[OR]=1.33;95% confidence interval[CI]=1.12-1.58;p=.001), postoperative pulmonary complications (OR=2.01;95%CI=1.31-3.08;p=.001), postoperative renal complications (OR=2.20;95%CI=1.27-3.80;p=.005), surgical site infection (OR=2.65;95%CI=2.19-3.20;p<.001), and prolonged hospital stay (OR=1.67; 95%CI=1.47-1.90; p<.001). Conclusions Patients with DM had a significantly higher risk of developing complications after spinal fusion, particularly pulmonary and renal complications, in addition to surgical site infections and had a longer length of stay. These findings are important for informed discussions of surgical risks with patients and families before surgery.