Editor-in-Chief: Kenneth D. Candido, MD
BACKGROUND: Neural blockade of the facet medial branch/L5 dorsal rami with local anesthetic with or without corticosteroid has been used to both diagnose and treat low back pain. Higher concentration lidocaine has been shown to be neurolytic in multiple in vivo, in vitro, and some clinical studies. This may make 10% lidocaine a possible neurolytic agent to prolong pain relief from facet blocks.
OBJECTIVE: Compare neurolytic effects of 10% lidocaine to prolong pain relief compared to bupivacaine/methylprednisolone (BM) in facet medial branch/L5 dorsal rami blocks (MBB).
METHODS: Retrospective review of 77 patients who received a 10% lidocaine MBB from after short term relief from MBB with BM. Comparison was made in visual analog scale (VAS) and duration of relief using Wilcoxon signed rank matched pairs test.
RESULTS: There was no significant difference between baseline median VAS prior to MBB with BM and 10% lidocaine and median days VAS recorded post each MBB ((P = 0.477). Median VAS immediately after BM MBB (17.5 mm) was not significantly different than after 10% Lidocaine MBB) of 18 mm (P = 0.341). Median duration of relief with 10% lidocaine was greater at 14 days versus BM at 3.5 days (P = 0.001). There was no significant correlation between the volume of 10% lidocaine at each level and performance measures: % change VAS post lidocaine MBB (P= 0.529), duration lidocaine MBB (P = 935), VAS pre-RFTC (P = 0.683).
LIMITATION: Retrospective, small study.
CONCLUSION: Ten percent lidocaine was moderately effective neurolytic agent with longer duration than BM.
Key words: Lidocaine, facet joint, neurolysis, low back pain