Diabetes and Diabetic Neuropathy Significantly Increase Short- and Long-Term Complications Following Single-Level Posterolateral Lumbar Fusion: A Propensity- Matched Cohort Study

Background Diabetes is a well-established risk factor for postoperative complications following lumbar fusion; however, the independent impact of diabetic neuropathy on outcomes after single-level posterolateral lumbar fusion (PLF) remains incompletely defined. Methods A retrospective cohort study was performed using a multicenter database of adults undergoing single-level PLF. Patients were stratified into three groups: non-diabetic, diabetic without neuropathy, and diabetic with neuropathy. Propensity score matching was used to balance demographics and comorbidities, generating three matched comparisons. Ninety-day medical and two-year mechanical and surgical complications were compared using risk ratios (RRs) with 95% confidence intervals (CIs). Results Among patients without neuropathy, diabetes was associated with higher 90-day postoperative infection (5.0% vs 4.0%, RR 1.25), sepsis (2.3% vs 1.7%, RR 1.33), and wound disruption (3.8% vs 2.9%, RR 1.31). At two years, this group had higher implant-associated infection (2.9% vs 2.3%, RR 1.26) and revision surgery (6.5% vs 5.7%, RR 1.14), with similar pseudarthrosis. Patients with diabetic neuropathy had substantially higher rates of infection, sepsis, wound disruption, pneumonia, mechanical complications, implant-associated infection, and revision surgery, with comparable pseudarthrosis. Direct comparison of diabetic patients with vs without neuropathy showed neuropathy independently increased postoperative infection, wound disruption, implant-associated infection, and revision surgery, with similar thromboembolic events and pseudarthrosis. # Conclusions Diabetes increases short-term medical and long-term surgical complications following single-level PLF, and coexisting diabetic neuropathy further amplifies these risks, underscoring the importance of neuropathy status in preoperative risk and perioperative management.