Impact of local steroid application in a minimally invasive transforaminal lumbar interbody fusion: results of a prospective, randomized, single-blind trial

: OBJECTIVELocal epidural steroid application may be associated with decreased pain and narcotic use in the immediate postoperative period following lumbar discectomy. However, local steroid delivery following lumbar fusion procedures has not been well characterized. This study aims to characterize the effect of local intraoperative depomedrol application on perioperative and postoperative outcomes following a single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).METHODSA prospective, randomized, single-blinded study was performed. A priori power analysis determined that 86 patients were needed to detect a difference of 1 point in the visual analog scale (VAS) pain score between groups. Ninety-three patients were randomized into depomedrol (DEPO) and no depomedrol (NODEPO) cohorts. Prior to surgical closure, DEPO patients received 1 ml depomedrol (80 mg) applied directly to the surgical site by using a Gelfoam carrier. NODEPO patients received 1 ml saline on the same Gelfoam carrier. Perioperative outcomes including acute postoperative pain and narcotic use were assessed for the duration of inpatient stay. Patient-reported outcomes (PROs) questionnaires including VAS back and leg pain scores, and Oswestry Disability Index (ODI) were administered preoperatively and at 6-week, 12-week, and 6-month follow-up. Outcomes for DEPO and NODEPO cohorts were compared using linear regression controlled for sex.RESULTSOf the 93 patients, 45 (48.4%) were randomized to DEPO and 48 (51.6%) to NODEPO. A greater percentage of DEPO patients were female (53.3% vs 27.1%, p = 0.010). There were no other significant differences in patient baseline characteristics. Similarly, operating time, estimated blood loss, and length of inpatient stay did not differ between cohorts. Patients in the DEPO cohort consumed fewer hourly narcotics on postoperative day 0 (5.3 vs 6.3 oral morphine equivalents/hour, p = 0.034). However, no differences in acute postoperative pain or total narcotics consumption were observed between groups. Preoperative VAS leg scores were statistically different between cohorts (p = 0.027). However, preoperative ODI and VAS back scores did not differ between groups. Additionally, DEPO and NODEPO groups experienced similar improvements in PROs at all postoperative time points.CONCLUSIONSLocal depomedrol use did not lead to decreases in acute postoperative pain or narcotics consumption after MIS TLIF. Additionally, local depomedrol was not associated with postoperative improvements in PROs. The findings of this randomized trial suggest that surgical and clinical outcomes following MIS TLIF may not be impacted by intraoperative application of depomedrol.Clinical trial registration no.: NCT03308084 (clinicaltrials.gov).