Effects of Topical Steroids on Postoperative Pain in Patients Undergoing Stand-Alone Lateral Lumbar Interbody Fusion.

Background Postoperative pain in the psoas and femoral nerve distribution is common following lateral lumbar interbody fusion (LLIF) surgery. Topical steroids have shown beneficial effects in spinal surgery. The effect of topical steroids applied directly to the psoas and the traversing nerve complexes in patients undergoing stand-alone LLIF (SA-LLIF) is unclear. Purpose The purpose of this retrospective cohort study is to investigate the efficacy of topical steroids in reducing postoperative pain when applied to the psoas muscle during SA-LLIF. Methods Patients who underwent SA-LLIF were included. Patient demographics, perioperative factors, length of stay (LOS), opioid consumption measured in oral morphine equivalents (OME), and pain scores on the numeric rating scale (NRS) were recorded and analyzed. Univariable and multivariable regression analyses were performed to assess the impact of topical steroid use on OME, NRS, and LOS. Subgroup analysis was conducted on patients who did not receive transversus abdominal plane (TAP) blocks. Results There was no significant difference between patients who received topical steroids and those who did not. However, in the subgroup analysis of those without tap block, NRS in the first 24 hours post-surgery was significantly lower in the topical steroids group (4.1 (3.0, 5.4) vs. 5.3 (3.9, 6.4) (p = 0.03)), while there was no significant difference in OME and LOS. In multivariable analysis, topical steroid use was an independent factor associated with decreased NRS in the first 24 hours post-surgery score (β = -0.74 (95% CI -1.22, -0.25)) (p < 0.01). Conclusions Topical steroids were associated with a lower 0-24-hour NRS score in patients who did not receive a TAP block. However, overall, topical steroids did not significantly improve pain measures during the postoperative period for patients undergoing SA-LLIF.