Establishing an Optimal “Cutoff” Threshold for Diagnostic Lumbar Facet Blocks

Abstract

Employing more stringent selection criteria for lumbar facet RF is likely to result in withholding a beneficial procedure from a substantial number of patients, without improving success rates.

Does Level of Response to SI Joint Block Predict Response to SI Joint Fusion?

“…Cohen et al examined the relationship between the response to lumbar facet blocks and the subsequent response to RF ablation of the nerves innervating lumbar facet joints. 17 In this prospective study, no cutoff reliably identified a patient population that responded better to lumbar facet RF ablation. In addition, there was very little correlation between the response to lumbar facet blocks and the eventual response to treatment, a finding that mirrors those of our study.…”

“…To qualify for the study, the pre-block NRS rating had to be at least 5 and at least one post-block score had to show a ≥50% reduction compared to pre-block. The average response to SIJB was calculated as (NRS preblock -average(NRS 30/60 ))/NRS preblock × 100%, as previously described by Cohen et al 17 A small number of patients who did not provide both 30 and 60 minute scores were eliminated from this analysis.…”

“…For instance, In patients with lumbar facet joint pain diagnosed by facet block, there was little correlation between pain relief during a medial branch block and subsequent response RF-based denervation of the facet. 17 In this report, we used a similar analytic approach to examine the correlation between the immediate response to SIJB and the 6-and 12-month pain and disability scores of patients undergoing SIJF in two prospective multicenter clinical trials.…”

Medial Branch Blocks or Intra-Articular Injections as a Prognostic Tool Before Lumbar Facet Radiofrequency Denervation

“…11 Some authors have also advocated higher analgesic cutoff values as the reference standard for designating a block as positive, 6 although a prospective study found no differences in RF denervation treatment outcomes when diagnostic blocks were stratified by percent pain relief. 48 On a similar note, RF denervation may not have been optimal in all cases. For example, a recent study showed that injecting corticosteroids before RF denervation decreases lesion size and that increasing the size of the cannulae, the time of lesioning, and the temperature will amplify lesion area.…”

Optimal Temperature for Radiofrequency Ablation of Lumbar Medial Branches for Treatment of Facet‐Mediated Back Pain

“…In attempt to improve outcomes, studies have been performed focusing on patients' selection based on their response to controlled diagnostic blocks to confirm the facetogenic etiology of their chronic low back pain, and ideal electrodes placement to optimize ablation of the culprit nerves . To establish the threshold cutoff for the diagnostic blocks, a multicenter prospective study was designed ( n = 61), which demonstrated there were no significant differences in the procedure outcomes with over 50% pain relief after the diagnostic blocks.…”