Ultrasound-Guided Modified Thoracolumbar Fascial Plane Block in Tianji Robot-Assisted Lumbar Internal Fixation: A Prospective, Randomized, and Non-Inferiority Study

PURPOSE: Ultrasound-guided modified thoracolumbar fascial plane block (MTLIP) has been reported effective for postoperative pain control following lumbar surgery. Although trauma of the Tianji robot-assisted lumbar internal fixation is reduced, the degree of pain cannot be ignored.MTLIP may improve operation efficiency and reduce puncture complications.This study aimed to explore whether MTLIP is not inferior to thoracolumbar fascial plane block (TLIP) in the treatment of lumbar internal fixation. METHODS: This prospective double-blinded, non-inferiority randomized trial enrolled patients underwent Tianji robot-assisted lumbar internal fixation between April and August 2022 to either MTLIP or TLIP. The primary outcome was an effective dermatomal block area after 30 min. Secondary outcomes included the numeric rating scale (NRS) scores, nerve block operation time, puncture times, image clarity, patient satisfaction, intraoperative opioid consumption, complications/adverse reactions, and Oswestry Disability Index (ODI). RESULTS: Sixty participants were randomized to MTLIP (n=30) and TLIP (n=30). The effective dermatomal block area 30 min after block was non-inferior in the MTLIP group (283.6 ± 62.6 cm(2)) compared with the TLIP group (261.4±53.2 cm(2)) (P=0.145; estimated mean difference: −22.17, 95% CI: −52.19, 7.85; smaller than the non-inferiority margin of 39.5). Compared with TLIP, MTLIP showed shorter operation time, smaller puncture times, and better target definition and satisfaction scores (all P<0.001). Sufentanil amount, remifentanil amount, PCIA sufentanil dosage, parecoxib amount, NRS scores (increased with time in the two groups but without inter-group differences), and complications were not significantly different between the two groups (all P>0.05). CONCLUSION: This non-inferiority trial supports the hypothesis that MTLIP yields a non-inferior effective dermatomal block area compared with TLIP for Tianji robot-assisted lumbar internal fixation. CLINICAL TRIALS REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2200058687);.