Wednesday, September 26, 2018 10:35 AM – 12:00 PM Understanding Lumbar Stenosis/Spondylolisthesis: 17. Preoperative lumbar corticosteroid injections and infection rates in lumbar arthrodesis

BACKGROUND CONTEXT Lumbar corticosteroid injections are commonly employed in the nonoperative management of lumbar spinal pathology. Their effect on subsequent surgery is unclear. Some studies suggest an elevated risk of postoperative infection, while other studies do not demonstrate an elevated risk. PURPOSE We sought to characterize the overall postoperative infection rate in patients undergoing lumbar spine arthrodesis in a military health system patient population and evaluate the correlation of lumbar corticosteroid injections to postoperative infection rate. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE All patients within the Military Health System Data Repository. OUTCOME MEASURES Postoperative infection rate. METHODS The Military Health System Data Repository was searched for all patients who underwent single level lumbar arthrodesis from 2009 to 2014. CPT codes were used to identify the subset of patients who also received preoperative lumbar corticosteroid injections. These patients were stratified by timing, type, and number of injections. Postoperative infection within 90 days of surgery was identified using ICD-9 codes. Infection rates were compared to the control group of patients who did not receive preoperative lumbar corticosteroid injections. RESULTS The search identified 3,403 patients who had undergone lumbar arthrodesis from 2009 to 2014 within the military health system. A total of 612 patients had received lumbar corticosteroid injections prior to surgery (348 epidural, 264 facet). The control group consisted of the remaining 2,791 patients. Overall postoperative infection rate was 1.47% with an infection rate in the injection group of 1.14% versus 1.54% in the control group. When stratified by time, infection rates ranged from 0% to 1.85% in the injection groups. No differences between control and injection groups reached statistical significance in any subgroup analysis. CONCLUSIONS This study demonstrates postoperative infection rate is not significantly increased in patients receiving lumbar corticosteroid injections prior to lumbar arthrodesis. No differences were observed in infection rates based on the type (facet vs. epidural) or number of injections prior to surgery. Furthermore, no significant differences were observed based on the timing of injections prior to surgery. This study demonstrates the safety of preoperative lumbar corticosteroid injections in the setting of lumbar arthrodesis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.