P132. Lumbar fusion during the COVID-19 pandemic: greater rates of morbidity and longer procedures

The coronavirus-19 (COVID-19) pandemic has altered the standard of care for spine surgery in many ways. However, there is a lack of literature evaluating the potential changes in surgical outcomes and perioperative factors for spine procedures performed during the pandemic. In particular, no large database study evaluating the impact of the COVID-19 pandemic on spine surgery outcomes has been published. To evaluate the impact of the COVID-19 pandemic on perioperative factors and postoperative outcomes of lumbar fusion procedures. Retrospective cohort study. Patients who underwent primary, elective lumbar fusionbetween 2019 and 2020. Thirty-day readmission, reoperation, morbidity, complications, operative time, non-home discharge disposition, length of hospital stay, total RVUs and RVUs per minute. The ACS-NSQIP database was queried for all patients who underwent primary lumbar fusion in 2019 and 2020. Exclusion criteria included cervical or thoracic fusion, arthroplasty, non-elective, emergency cases, deformity procedures, malignancy, preoperative sepsis, wound infection and missing perioperative variables. Patients were grouped into cohorts based on 2019 or 2020 operation year. Multivariate logistic and Poisson regression models were utilized to evaluate the impact of 2020 operative year on postoperative outcomes. A total of 27,446 patients were included in the analysis (12,473 cases in 2020). For the 2020 cohort, non-white race (24.9% vs 23.4%, p=0.004), functional dependence (1.8% vs 1.4%, p=0.022), congestive heart failure (0.5% vs 0.3%, p=0.015), and ASA class =3 (53.5% vs 52.2%, p=0.037) were more common. Lumbar fusions performed in 2020 were also associated with longer mean operative time (209.3±99.3 vs. 205.9±98.6 minutes, p=0.005) and higher mean fusion levels (1.45±0.69 vs 1.41±0.65, p 0.05). However, operation year 2020 independently predicted morbidity (OR 1.087 [95% CI 1.007-1.172], p=0.032), pneumonia (1.407 [1.039-1.906], p=0.027), DVT (1.508 [1.106-2.056], p=0.009) and sepsis (1.537 [1.101-2.146], p=0.012). In terms of perioperative variables, operation year 2020 predicted greater operative time (1.012 [1.001-1.013], p=0.046), non-home discharge (0.690 [0.642-0.743], p