Anesthesiology. 2010 July 6

Multicenter, Randomized, Comparative Cost-effectiveness Study Comparing 0, 1, and 2 Diagnostic Medial Branch (Facet Joint Nerve) Block Treatment Paradigms before Lumbar Facet Radiofrequency Denervation.

Cohen SP, Williams KA, Kurihara C, Nguyen C, Shields C, Kim P, Griffith SR, Larkin TM, Crooks M, Williams N, Morlando B, Strassels SA

BACKGROUND: Among patients presenting with axial low back pain, facet arthropathy accounts for approximately 10-15% of cases. Facet interventions are the second most frequently performed procedures in pain clinics across the United States. Currently, there are no uniformly accepted criteria regarding how best to select patients for radiofrequency denervation.

METHODS: A randomized, multicenter study was performed in 151 subjects with suspected lumbar facetogenic pain comparing three treatment paradigms. Group 0 received radiofrequency denervation based solely on clinical findings; group 1 underwent denervation contingent on a positive response to a single diagnostic block; and group 2 proceeded to denervation only if they obtained a positive response to comparative blocks done with lidocaine and bupivacaine. A positive outcome was predesignated as >/=50% pain relief coupled with a positive global perceived effect persisting for 3 months.

RESULTS: In group 0, 17 patients (33%) obtained a successful outcome at 3 months versus eight patients (16%) in group 1 and 11 (22%) patients in group 2. Denervation success rates in groups 0, 1, and 2 were 33, 39, and 64%, respectively. Pain scores and functional capacity were significantly lower at 3 months but not at 1 month in group 2 subjects who proceeded to denervation compared with patients in groups 0 and 1. The costs per successful treatment in groups 0, 1, and 2 were $6,286, $17,142, and $15,241, respectively.

CONCLUSIONS: Using current reimbursement scales, these findings suggest that proceeding to radiofrequency denervation without a diagnostic block is the most cost-effective treatment paradigm.