Summary of recommendations
| Topic | Recommendation/Findings | Level of evidence and certainty |
| Value of history and physical examination to select patients for blocks | There are no examination or historical signs that reliably predict response to lumbar facet blocks. Paraspinal tenderness and radicular symptomatology may be weakly predictive of positive and negative blocks, respectively. The levels targeted should be based on clinical presentation (eg, tenderness, pain patterns, imaging if available). | Grade C, low level of certainty |
| Correlation between imaging and facet block and RFA outcomes, and whether imaging is necessary before blocks | There is moderate evidence for SPECT before MBB. There is weak evidence for SPECT before IA blocks. There is weak evidence for MRI, CT and scintigraphy before MBB and IA blocks. | Grade C, moderate level of certainty Grade D, low level of certainty Grade D, low level of certainty |
| Requirement of conservative treatment including physical therapy before facet blocks | Consistent with clinical practice guidelines, we recommend a 3-month trial of different conservative treatments before facet joint interventions. | Grade C, low level of certainty |
| Necessity of image guidance for lumbar facet blocks and RFA | We recommend CT or preferably fluoroscopy be used for lumbar MBB, although ultrasound may be considered in certain contexts. For IA injections, we recommend CT, although fluoroscopy can be considered in some cases. | Grade C, low level of certainty |
| For RFA, we recommend using fluoroscopy. | Grade B, low level of certainty | |
| Diagnostic and prognostic value of facet blocks | IA injections are theoretically more diagnostic than MBB, although they are characterized by a high technical failure rate and poorer predictive value before RFA. Both MBB and IA injections are better than saline injections as prognostic tools before RFA. | Grade B, low level of certainty |
| MBB vs IA injections before RFA | MBB should be the prognostic injection of choice before RFA. IA injections may be used for both diagnostic and therapeutic purposes in some individuals (eg, young people with inflammatory pain, people at risk of RFA complications). | Grade C, moderate level of certainty. |
| Effect of sedation on diagnostic and prognostic utility | Consistent with guidelines, sedation should not be routinely used in the absence of individual indications. | Grade B, low-to-moderate level of certainty |
| Ideal volume for facet blocks | Lumbar MBB should be performed with a volume <0.5 mL to prevent spread to adjacent structures, and IA injections should be done with a volume <1.5 mL to prevent aberrant spread and capsular rupture. | Grade C, low level of certainty |
| Therapeutic benefit from MBB and IA injections | We recommend against the routine use of both therapeutic MBB and IA injections, although we acknowledge there may be some contexts in which these can be useful (eg, prolonged relief from prognostic blocks, contraindications to RFA). | Grade D, moderate level of certainty |
| Cut-off for designating a prognostic block as positive and use of non-pain score outcome measures | We recommend that >50% pain relief be used as the threshold for designating a prognostic block as positive, but recognize that using higher cut-off values may result in higher RFA success rates. Secondary outcomes such as activity levels may also be considered when deciding whether to proceed with RFA. | Grade B, moderate level of certainty |
| Number of prognostic blocks performed before RFA | We recommend a single block. Although using multiple blocks may improve RFA success rates, it will also result in patients who might benefit from RFA being denied treatment. | Grade C, low-to-moderate level of certainty |
| Evidence for large RF lesions | There is indirect evidence, and limited direct evidence, that techniques that result in larger lesions (eg, larger electrodes, higher temperatures, longer heating times, proper electrode orientation, fluid modulation) improve outcomes. | Grade C, low level of certainty that larger lesions increase the chance of capturing nerves. Grade I, low level of certainty that larger lesions increase duration of pain relief. |
| Electrode orientation | We recommend positioning the electrode in an orientation near-parallel to the nerve. | Grade B, low level of certainty |
| Use of sensory and motor stimulation before RFA | Sensory stimulation should be used when single lesions are anticipated. When multiple lesions are planned, the evidence for sensory stimulation is inconclusive. Motor stimulation may be beneficial for safety and effectiveness purposes. | Grade C, low level of certainty Grade I, moderate level of certainty Grade B, low level of certainty |
| Mitigating complications | Intravascular uptake can adversely affect the validity of MBB and we recommend aspiration and real-time contrast injection. | Grade C, low levelof certainty |
| Anticoagulation medications should be continued for facet blocks and RFA, and cases that might warrant discontinuation should be discussed with relevant healthcare providers. | Grade B, moderate level of certainty | |
| Injection of steroid after RFA may prevent neuritis. | Grade C, low levelof certainty | |
| Confirming electrode placement in multiple views andusing sensorimotor testing may reduce the risk of nerveroot injury. | Grade B, low levelof certainty | |
| RFA can result in paraspinal muscle degeneration andpossibly disc degeneration, though the clinical relevanceof this is unclear. We recommend a discussion of thispossibility with patients, and consideration of physicaltherapy before and after RFA to reduce the risk. | Grade C, low levelof certainty | |
| Interference with implanted electrical devices can occur,and physicians should consult with relevant healthcareteams regarding recommendations (eg, programmingpacemakers to asynchronous mode, turning offneurostimulators). Bipolar modes may be safer thanmonopolar, and grounding pads should be placed awayfrom implanted cardiac devices, but not too close to theneurotomy site (risk of tissue burn). Avoid excessivesedation. | Grade C, low levelof certainty | |
| Burns may occur from equipment malfunction or lesionextension to the skin (less likely). Checking equipment,and properly positioning the grounding on a dry, cleanshaven lower extremity devoid of scars may minimize thisrisk. | Grade B,moderate-to-highlevel of certainty | |
| Spine surgery is associated with lower RFA success rates,and physicians should check placement of RF probes inmultiple fluoroscopic views and avoid contact withhardware to prevent thermal injury. | Grade C, low levelof certainty | |
| Difference in standards between clinical trials and clinical practice | Providers involved in clinical trials and clinical practice may have different goals that warrant different selection and performance criteria. Areas that might warrant discrepancies include the use of contrast during MBB, number of blocks performed, prognostic block cut-off for identifying an RFA candidate and use of sensorimotor stimulation. | Grade A, moderate level of certainty |
| Repeating RFA | We recommend repeating RFA in individuals who obtained at least 3 (and preferably 6) months of relief, up to two times per year. The success rate for repeat RFA decreases for successive procedures but remains above 50%. | Grade B, moderate level of certainty |
| Repeating prognostic blocks is not routinely necessary in patients who experience a recurrence of their baseline pain in a physiological timeframe. | Grade C, low level of certainty |
online supplementary figure 1
IA, intra-articular; LA, local anesthetic; MBB, medial branch block; RF, radiofrequency; RFA, radiofrequency ablation; SPECT, single photon emission computed tomography.