The effect of lumbar corticosteroid injections on postoperative infection in lumbar arthrodesis surgery

We sought to characterize the association between lumbar corticosteroid injections and postoperative infection rate for patients in the Military Health System undergoing lumbar arthrodesis. The Military Health System Data Repository was searched for all patients undergoing lumbar arthrodesis from 2009 to 2014. Current Procedural Terminology (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. Infection rates were compared to the control group of patients who did not receive preoperative lumbar corticosteroid injections. The search identified 3403 patients who had undergone lumbar arthrodesis from 2009 to 2014 within the Military Health System. 612 patients had received lumbar corticosteroid injections prior to surgery (348 epidural, 264 facet). The control group consisted of the remaining 2791 patients. Overall post-operative 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 injection and control groups reached statistical significance in any subgroup analysis. Post-operative infection rate is not significantly increased in patients receiving lumbar corticosteroid injections (LCSIs) prior to lumbar arthrodesis. No differences were observed in infection rates based on timing, type, or number of injections prior to surgery.