Effectiveness of Lumbar Facet Joint Blocks and Predictive Value before Radiofrequency Denervation

Abstract

What We Already Know about This Topic What This Article Tells Us That Is New Background With facet interventions under scrutiny, the authors’ objectives were to determine the effectiveness of different lumbar facet blocks and their ability to predict radiofrequency ablation outcomes. Methods A total of 229 participants were randomized in a 2:2:1 ratio to receive intraarticular facet injections with bupivacaine and steroid, medial branch blocks, or saline. Those with a positive 1-month outcome (a 2-point or more reduction in average pain score) and score higher than 3 (positive satisfaction) on a 5-point satisfaction scale were followed up to 6 months. Participants in the intraarticular and medial branch block groups with a positive diagnostic block (50% or more relief) who experienced a negative outcome proceeded to the second phase and underwent radiofrequency ablation, while all saline group individuals underwent ablation. Coprimary outcome measures were average reduction in numerical rating scale pain score 1 month after the facet or saline blocks, and average numerical rating scale pain score 3 months after ablation. Results Mean reduction in average numerical rating scale pain score at 1 month was 0.7 ± 1.6 in the intraarticular group, 0.7 ± 1.8 in the medial branch block group, and 0.7 ± 1.5 in the placebo group; P = 0.993. The proportions of positive blocks were higher in the intraarticular (54%) and medial branch (55%) groups than in the placebo group (30%; P = 0.01). Radiofrequency ablation was performed on 135 patients (45, 48, and 42 patients from the intraarticular, medial branch, and saline groups, respectively). The average numerical rating scale pain score at 3 months was 3.0 ± 2.0 in the intraarticular, 3.2 ± 2.5 in the medial branch, and 3.5 ± 1.9 in the control group (P = 0.493). At 3 months, the proportions of positive responders in the intraarticular, medial branch block, and placebo groups were 51%, 56%, and 24% for the intraarticular, medial branch, and placebo groups, respectively (P = 0.005). Conclusions This study establishes that facet blocks are not therapeutic. The higher responder rates in the treatment groups suggest a hypothesis that facet blocks might provide prognostic value before radiofrequency ablation.

Consensus practice guidelines on interventions for lumbar facet joint pain from a multispecialty, international working group

“…78 Despite consistent evidence of only small effect sizes for conservative treatments (including PT) in chronic LBP, 79 80 proponents still recommend conservative care trials due to their relatively lower costs and risks. This position appears to be supported by interventional pain researchers since the inclusion criteria within prospective studies of facet joint interventions usually, 18 19 81–83 but not always, 84 85 include a preceding trial of conservative treatment. Yet, there is no existing evidence that demonstrates the appropriate timing or optimal duration of conservative treatments for chronic LBP.…”

“…MBB remained a significant predictor for positive treatment response even when controlling for confounding factors. In the subsequent randomized, three-arm FACTS study by Cohen et al , 18 the authors found a false-positive rate of 30% when defined as significant pain relief following a lumbar MBB with saline. The proportions of positive responders to RFA in the IA and medial block diagnostic groups were 51% and 56%, respectively.…”

“… 99 For lumbar IA injections, studies have reported high rates of failed blocks, ranging between 29% and 38% per joint using fluoroscopy. 18 100 However, the precise anatomical osseous resolution afforded by CT imaging may yield higher success rates. In one retrospective study, Weininger et al reported a 94% success rate for 85 lumbar IA facet blocks.…”

“…However, practically, there is a high rate of failed IA injections ranging between 29% and 38% per joint, and 46% and 64% per patient. 18 100 …”

Radio Frequency in the Treatment of Lumbar Facet Joint Arthropathy: Indications and Technical Notes

“…It is still a very controversial procedure in terms of efficiency. Some studies showed its superiority to placebo or conservative treatment where others were not conclusive [4][5][6]. We consider it as a safe, minimally invasive, inexpensive procedure.…”