Facet Nerve Denervation: Where is the evidence
Abstract
Radiofrequency facet denervation consists of applying Radiofrequency thermocoagulation to the median branch of the dorsal ganglion supplying the innervation of the facet joints with a rationale to alleviate pain in that region. Although very frequently used in many pain centers, studies showing the evidence are minuscule. There are two systematic reviews of RCT s on radiofrequency facet denervation which may be seriously considered.(Geurts et al 2001,Niemisto et al 2003- Cochrane review) The Cochrane review included 4 studies of facet denervation.(Gallagher 1994,Lecraire 2001,Sanders and Zuurmond 1999,van Kleef 1999). There is conflicting evidence that RF denervation is more successful then placebo for eliciting short-term or long-term improvements in pain or functional disability in mechanical chronic low back pain.(Level C) There is also limited evidence that intraarticular denervation is more effective then extra-articular denervation. (Level C) Patients subject to chronic facet pain are the candidates for facet denervation. However in practical terms these patients are very difficult to define because there are no clinical tests of facet joint pain and there are a high propotion of positive results to placebo from prognostic blocks. Patients selected for facet denervation should firstly have a diagnostic block,twice with a very low volume of anaesthetic(0.5 ml) at the target location;they should have consistent results with at least 80% pain relief.( Dreyfuss 2000) There is a need for further high quality RCTs with larger patient samples. careful preselection of patients with diagnostic blocks, longer follow-ups and meaningful standardized outcomes.
