The Effectiveness of Cervical Medial Branch Thermal Radiofrequency Neurotomy Stratified by Selection Criteria: A Systematic Review of the Literature Andrew Engel, MD,* Wade King, MMedSc, MMed(Pain), † Byron J. Schneider, MD, ‡ Belinda Duszynski, § and Nikolai Bogduk, MD, PhD ¶ *Affordable Pain Management, Chicago, Illinois, USA; † Mayo Multidisciplinary Pain Clinic, Mayo Private Hospital, Taree, NSW, Australia; ‡ Department of Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, Tennessee; § Spine Intervention Society, Hinsdale, Illinois, USA; ¶ University of Newcastle, Faculty of Health and Medicine, Newcastle, Australia Funding sources: No funding was received in preparation of this manuscript. Conflicts of interest: None of the authors has any financial conflicts of interest to disclose. Correspondence to: Andrew J. Engel, MD, Affordable Pain Management, 5327 N Sheridan Road, Suite B, Chicago, IL 60640, USA. Tel: 773-944- 0365; Fax: 773-944-0470; E-mail: engel.andrew@gmail.com. Abstract Objective. To determine the effectiveness of cervical medial branch thermal radiofrequency neurotomy in the treat- ment of neck pain or cervicogenic headache based on different selection criteria. Design. Comprehensive systematic review. Methods. A comprehensive literature search was conducted, and the authors screened and evaluated the studies. The Grades of Recommendation, Assessment, Development, and Evaluation system was used to assess all eligible studies. Outcome Measures. The primary outcome measure assessed was the success rate of the procedure, defined by varying degrees of pain relief following neurotomy. Data are stratified by number of diagnostic blocks and degree of pain relief. Results. Results varied by selection criteria, which included triple placebo-controlled medial branch blocks, dual comparative medial branch blocks, single medial branch blocks, intra-articular blocks, physical examination findings, and symptoms alone. Outcome data showed a greater degree of pain relief more often when patients were selected by triple placebo-controlled medial branch blocks or dual comparative medial branch blocks, producing 100% relief of the index pain. The degree of pain relief was similar when triple or dual comparative blocks were used. Conclusions. Higher degrees of relief from cervical medial branch thermal radiofrequency neurotomy are more often achieved, to a statistically significant extent, if patients are selected on the basis of complete relief of in- dex pain following comparative diagnostic blocks. If selected based on lesser degrees of relief, patients are less likely to obtain complete relief. Key words: Radiofrequency Neurotomy; Neck Pain; Headache; Cervical; Zygapophysial Joint Introduction When defined in the strictest terms, cervical medial branch thermal radiofrequency neurotomy (CMBTRFN) is a minimally invasive procedure for the treatment of pain mediated by one or more of the medial branches of the cervical dorsal rami. In practical terms, it is a treat- ment for pain stemming from one or more of the cervical zygapophysial joints, as, of all the structures innervated by the cervical medial branches, the zygapophysial joints are the only ones that theoretically might harbor a source of chronic pain. There are no known causes of chronic pain that discretely affect the muscles that are segmen- tally innervated by individual medial branches [1]. Although myofascial pain or trigger points might seem to be a competing cause of pain, the diagnosis of these enti- ties in the cervical spine has not been validated and lacks reliability [2]; they cannot be distinguished from tender V C The Author(s) 2020. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com 2726 Pain Medicine, 21(11), 2020, 2726–2737 doi: 10.1093/pm/pnaa219 Advance Access Publication Date: 15 September 2020 Review Article Downloaded from https://academic.oup.com/painmedicine/article/21/11/2726/5906111 by guest on 13 November 2021