title: Medial Branch Blocks or Intra-Articular Injections as a Prognostic Tool Before Lumbar Facet Radiofrequency Denervation: A Multicenter, Case-Control Study.
abstract: BACKGROUND
  Medial branch blocks (MBBs) and intra-articular (IA) facet joint injections are both used to diagnose facet joint pain and are presumed to be equivalent. No study has sought to determine which has a better prognostic value before radiofrequency (RF) denervation.
  
  
  METHODS
  A case-control study was performed at 4 institutions in which RF denervation outcomes in patients who obtained 50% or more pain relief from either MBB (n = 212) or IA injections (n = 212) were compared. "Control" patients (MBB) were matched to "cases" by treating physician, last name, and date of treatments. During data mining, 87 patients were identified who underwent RF ablation after receiving both IA injections and MBB and were used for secondary analyses.
  
  
  RESULTS
  A total of 70.3% of MBB patients experienced 50% or more pain relief at the 3-month follow-up versus 60.8% in those who underwent IA injections (P = 0.041). In multivariable analysis, undergoing MBB was associated with RF treatment success (odds ratio [OR], 1.57; 95% confidence interval [95% CI], 1.0-2.39; P = 0.036), whereas opioid use (OR, 0.52; 95% CI, 0.34-0.79; P = 0.002) and previous back surgery (OR, 0.60; 95% CI, 0.38-0.95; P = 0.028) were associated with treatment failure. No significant differences were noted between MBB alone and combination treatment or single versus multiple blocks. In the secondary multivariable analysis including the combination IA + MBB group, MBB alone was again independently associated with an RF ablation treatment success (OR, 1.73; 95% CI, 1.12-2.67; P = 0.014).
  
  
  CONCLUSIONS
  When used as a prognostic tool before lumbar facet radiofrequency, MBB may be associated with a higher success rate than IA injections. Our results should be confirmed by large, prospective, randomized studies.
authors.affiliation: From the *Departments of Anesthesiology and Critical Care Medicine and Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, MD; †Uniformed Services University of the Health Sciences, Bethesda, MD; ‡Department of Anesthesiology, Seoul National University School of Medicine, Seoul, Korea; §Department of Anesthesiology, University of Michigan, Ann Arbor, MI; ∥Department of Surgery, Landstuhl Regional Medical Center, Landstuhl, Germany; **Parkway Neuroscience and Spine Institute, Hagerstown, MD; and ††Walter Reed National Military Medical Center, Bethesda, MD.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Cohen
authors.forename: Jee Youn
authors.initials: JY
authors.lastname: Moon
authors.forename: Chad M
authors.initials: CM
authors.lastname: Brummett
authors.forename: Ronald L
authors.initials: RL
authors.lastname: White
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Larkin
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D015142:Baltimore; D002045:Bupivacaine / Q000008:administration & dosage* / Q000009:adverse effects; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D057225:Data Mining; D016208:Databases, Factual; D003714:Denervation / Q000379:methods*; D005260:Female; D005858:Germany; D006801:Humans; D007270:Injections, Intra-Articular; D016015:Logistic Models; D017116:Low Back Pain / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008159:Lumbar Vertebrae / Q000187:drug effects* / Q000294:innervation / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D016017:Odds Ratio; D010147:Pain Measurement; D018579:Patient Selection; D011237:Predictive Value of Tests; D056910:Republic of Korea; D012189:Retrospective Studies; D016896:Treatment Outcome; D021801:Zygapophyseal Joint / Q000187:drug effects* / Q000294:innervation / Q000601:surgery*
chemical_list: D000779:Anesthetics, Local; D002045:Bupivacaine