title: Incidence of inadvertent intra-articular lumbar facet joint injection during fluoroscopically guided interlaminar epidural steroid injection.
abstract: OBJECTIVE
  To determine the incidence of inadvertent lumbar facet joint injection during an interlaminar epidural steroid injection (ESI).
  
  
  METHODS
  A total of 686 interlaminar lumbar ESIs were performed from January 1, 2009 to December 31, 2009. Archived images from these cases were retrospectively reviewed on the PACS. Positive cases of inadvertent lumbar facet joint injection were identified by the characteristic sigmoid-shaped contrast pattern projecting over the posterior elements on the lateral view and/or ovoid contrast projecting over the facet joints on the anteroposterior (AP) view.
  
  
  RESULTS
  Eight positive events were identified (1.2%). There was no statistically significant gender or lumbar level predilection. In 3/8 of the positive cases (37.5%), the inadvertent facet joint injection was recognized by the operator. The needle was repositioned as a result, and contrast within the posterior epidural space was documented by the end of the procedure. In 5/8 of the positive cases (62.5%), the patients reported an immediate decrease in the presenting pain.
  
  
  CONCLUSIONS
  The incidence of inadvertent lumbar facet joint injection during an interlaminar epidural steroid injection is low. Recognizing the imaging features of this event permits the operator to redirect the needle tip into the epidural space and/or identify the facet joint(s) as a source of the patient's presenting pain.
authors.affiliation: Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Imaging & Intervention, 55 Fruit Street, Yawkey 6E, Boston, MA 02114, USA. ajhuang@partners.org
authors.forename: Ambrose J
authors.initials: AJ
authors.lastname: Huang
authors.forename: William E
authors.initials: WE
authors.lastname: Palmer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001175:Arthrography / Q000706:statistics & numerical data*; D001416:Back Pain / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000453:epidemiology*; D001900:Boston / Q000453:epidemiology; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000453:epidemiology*; D005260:Female; D005471:Fluoroscopy / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007268:Injections, Epidural / Q000706:statistics & numerical data; D007270:Injections, Intra-Articular / Q000706:statistics & numerical data*; D008297:Male; D008508:Medication Errors; D015641:Radiography, Interventional; D018570:Risk Assessment; D012307:Risk Factors; D013256:Steroids / Q000008:administration & dosage*; D021801:Zygapophyseal Joint
chemical_list: D013256:Steroids