title: Prevalence of facet joint pain in chronic low back pain in postsurgical patients by controlled comparative local anesthetic blocks.
abstract: OBJECTIVE
  To evaluate the prevalence of facet joint pain in patients with chronic low back pain (CLBP) after surgical intervention(s).
  
  
  METHODS
  A prospective, nonrandomized, consecutive study.
  
  
  METHODS
  An ambulatory interventional pain management setting.
  
  
  METHODS
  The prevalence of facet joint pain was evaluated in patients with CLBP after various surgical intervention(s) referred to an interventional pain management practice. The sample was derived from 282 patients with persistent CLBP after various surgical intervention(s). Of these, 242 patients consented to undergo interventional techniques. A total of 117 consecutive patients with chronic, nonspecific low back pain, after lumbar surgical intervention(s) were evaluated with controlled, comparative local anesthetic blocks.
  
  
  METHODS
  Controlled, comparative local anesthetic blocks (1% lidocaine or 1% lidocaine followed by .25% bupivacaine) under fluoroscopic visualization using 0.5mL to block each facet joint nerve.
  
  
  METHODS
  A positive response was defined as at least 80% reduction of pain with ability to perform previously painful movements. A positive response was considered to be pain relief from the lidocaine block lasting at least 1 hour or at least 2 hours or greater than duration of relief with lidocaine when bupivacaine was used. Controlled, comparative local anesthetic blocks were used to eliminate false-positive results. Valid information is only obtained by performing controlled blocks in the form of comparative local anesthetic blocks, in which, on 2 separate occasions, the same joint is anesthetized by using local anesthetics with different durations of action. If patients obtained appropriate response with both blocks, they were considered a positive. If they obtained appropriate response with lidocaine but not with bupivacaine, they were considered false-positive, whereas if the response was negative with lidocaine, they were considered negative.
  
  
  RESULTS
  The prevalence of lumbar facet joint pain in patients with recurrent pain after various surgical intervention(s) was 16% (95% confidence interval, 9%-23%). The false-positive rate with a single block with lidocaine was 49%.
  
  
  CONCLUSIONS
  Facet joints are clinically important pain generators in a small but significant proportion of patients with recurrent CLBP after various surgical intervention(s).
authors.affiliation: Pain Management Center of Paducah, Paducah, KY, USA. drm@apex.net
authors.forename: Laxmaiah
authors.initials: L
authors.lastname: Manchikanti
authors.forename: Rajeev
authors.initials: R
authors.lastname: Manchukonda
authors.forename: Vidyasagar
authors.initials: V
authors.lastname: Pampati
authors.forename: Kim S
authors.initials: KS
authors.lastname: Damron
authors.forename: Carla D
authors.initials: CD
authors.lastname: McManus
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local; D002045:Bupivacaine; D005260:Female; D006801:Humans; D008012:Lidocaine; D017116:Low Back Pain / Q000209:etiology / Q000534:rehabilitation / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D011183:Postoperative Complications / Q000534:rehabilitation / Q000628:therapy*; D015995:Prevalence; D011446:Prospective Studies; D021801:Zygapophyseal Joint
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine