Table 8.

Studies comparing facet joint radiofrequency ablation outcomes based on per cent relief with diagnostic blocks

Study	Design	Number of patients	Results	Comments
Cohen et al 6	Prospective	61	54% success rate, with no difference in categorical outcomes or correlation in 10 percentage point increments. Only one in six people who underwent RFA after obtaining <50% relief on MBB had positive outcome.	Cut-offs at 10% increments from 50% to 100% relief. Poorer outcomes in six individuals who had <50% relief with single block; ≥50% pain relief 6 months after RFA designated as positive response.
Cohen et al 199	Retrospective	262	52% success rate in ≥50% cut-off group vs 56% in ≥80% group.	Multicenter study evaluating single blocks.
Holz and Sehgal,135	Retrospective	50	53.1% relief in individuals with >70% relief on both MBB vs 44.4% relief in those with >70% relief on only one of twio MBB.	Included both lumbar and cervical facet RFA. Sixty patients lost to follow-up. Greatest pain relief in patients with >8 hours of pain relief after lidocaine blocks.
Cohen et al 69	Retrospective	92	56% success rate in ≥50% cut-off group vs 58% in ≥80% group.	Evaluated cervical facet RFA. Multicenter study evaluating single blocks.
Stojanovic et al 68	Retrospective	77	47% success rates in both high index group who obtained ≥80% pain relief on two blocks and those who received one block, or had >80% relief on only one of two blocks.	Seventeen people in ‘high index’ group.
Cohen et al 134	Retrospective, case-control	511	74% pain relief from diagnostic facet blocks in individuals with a positive RF outcome vs 72% in those with a negative outcome.	Multicenter study designed to determine whether IA or MBB are superior as prognostic tests.
Derby et al 8	Retrospective	51	Success in 22% (2/9) of patients with ≥50% but <70% relief vs 79% (33/42) in those with ≥70% relief.	>50% relief designated as success. Patients had both single and double blocks.
Manchikanti et al 201	Retrospective	110 to 152 in control comparison group	At 1-year follow-up, 93% in 80% cut-off group had a positive outcome vs 73% in the 50% cut-off group. At 2 years, success rates were 89.5% and 51%, respectively.	Compared double block outcomes with their own historical controls. Patients treated with both ‘therapeutic’ MBB and RFA (breakdown not provided). Since MBB have not been shown to provide long-term benefit, validity is questionable.
McCormick et al 205	Prospective	55, 28 who had 2 blocks and 27 who had a single block	In the single block group, 43% and 46% had ≥50% improvement in pain and function vs 59% and 63% in those who had two blocks.	Those who had 50%–74% relief on the initial block underwent a confirmatory block, while those who obtained >75% relief proceeded to RFA.
Derby et al 206	Retrospective	182	Single block group: ≥50 <80% relief 50% RFA success rate; ≥80% relief: 72% RFA success rate. Double block group: ≥50 <80% relief: 85% RFA success rate; ≥80% relief: 100% success rate (13/13).	Unclear why some patients underwent single vs double blocks. Excluded some patients with suspected multiple sources of pain.

IA, intra-articular; MBB, medial branch block; n, number; RFA, radiofrequency ablation.