Duger 2012.

Methods	RCT; random assignment to 3 groups
Participants	Department of Anesthesiology, Cumhuriyet University School of Medicine, Sivas, Turkey (N = 120) Inclusion criteria Single‐sided low back pain arising from facet joint Between 18 and 60 years of age Complaints longer than 6 months Limited functions and daily life Presented with at least 2 of the 4 troubling symptoms of facet syndrome, including back pain aggravated by hyperextension and rotation, morning stiffness or pain increasing in the morning, local tenderness over 1 or more facet joints and hip and buttock pain of a non‐radicular distribution Exclusion criteria Patients not accepting the procedure Patients not giving informed consent Coagulation defect Major depression and uncontrolled psychiatric disorder Pregnancy or lactation Respiratory or cardiac problems in prone position Opioid treatment during previous month Undergoing surgical procedure at the same site Infection at the procedure site Disc‐related radicular symptoms
Interventions	RF denervation group In group R (RF denervation), localisation of radiofrequency electrode in the facet joint causing pain was determined by sensorial stimulus and C‐armed scope device. Pulse RF thermocoagulation was applied for 6 minutes at 40°C with RF lesion generator Injection group In group B (block), after C‐arm scope‐guided determination of injection point, 1.5 mL of 20 mg methylprednisolone acetate mixed with 5 mg bupivacaine was injected into the facet joint RF denervation and injection groups In Group RB (RF denervation and block) patients, localization of electrode in the facet joint causing pain was determined by sensorial stimulus and scope device. Pulsed RF thermocoagulation was applied for 6 minutes at 40°C and a 1.5 ml mixture of 20 mg methylprednisolone acetate and 5 mg bupivacaine was injected to the facet joint at the same localization
Outcomes	Pain intensity: change in VAS score at 1 month: ‐4.4 (R), ‐1.74 (B), ‐4.2 (RB). Significant difference between R and B; and between RB and B Pain intensity: change in VAS score at 6 months: ‐4.2 (R), ‐0.6 (B), ‐4.3 (RB). Significant difference between R and Bl and between RB and B Pain intensity: change in VAS score at 12 months: ‐3.3 (R), ‐0.1 (B), ‐3.4 (RB). Significant difference between R and Bl and between RB and B
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Remained unclear from text
Allocation concealment (selection bias)	Unclear risk	Remained unclear from text
Blinding (performance bias and detection bias) All outcomes ‐ patients?	High risk	No stimulation in injection group before treatment. Therefore, decision was made that it was impossible to blind participants
Blinding (performance bias and detection bias) All outcomes ‐ providers?	High risk	All procedures performed by the same physician
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	High risk	Participant reported outcome measures
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	Unclear risk	Incomplete information on participant flow and follow‐up
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	Unclear risk	Remained unclear from text
Selective reporting (reporting bias)	Unclear risk	No protocol available
Baseline characteristics similar?	Low risk	Table 1. Groups comparable on relevant demographic and clinical variables
Co‐interventions avoided or similar?	Unclear risk	Remained unclear from text
Compliance acceptable?	Low risk	Irrelevant: intervention if performed only once
Timing of outcome assessments similar?	Low risk	Table 2. Baseline, day 1, day 2, week 1, week 2, month 1, month 6 and month 12 measures