title: Ultrasound-guided facet joint injections in the middle to lower cervical spine: a CT-controlled sonoanatomic study.
abstract: OBJECTIVE
  The aim of this study was to investigate the efficacy of ultrasound as a guiding tool for simulated cervical facet joint injections in cadavers.
  
  
  METHODS
  A total of 40 ultrasound examinations at 5 levels (C6-7 to C2-3) were performed on 4 embalmed cadavers. The zygapophyseal joints were located with ultrasound. First, the transverse processes of C6 and C7 were established and the facet joint of C6-7 was demonstrated. The midpoint of this joint space, defined as the middle of its cranio-caudal extension on its lateral surface, was taken as a reference point. Ipsilateral distances (A, B, C, and D) between this point and each one of the 4 facet joints of the cervical spine up to the facet joints C2-3 were then computed. Subsequently, coronal computed tomography (CT) scans were taken to verify these distances. In a second experiment, a spinal needle was advanced under ultrasound guidance to the zygapophyseal joints from C2-3 to C6-7 on both sides of 1 cadaver. The exact placement of the needle tips was again verified by CT.
  
  
  RESULTS
  In 4 attempts, a depiction of the joint space was not possible. Ultrasound and CT provided the same mean measurements of 1.2+/-0.2 cm, 2.0+/-0.3 cm, 3.0+/-0.2, and 4.0+/-0.5 cm for distances A, B, C, and D, respectively. All 10 needle tips were located in the joint space during simulated facet joint injections, as also verified by CT.
  
  
  CONCLUSIONS
  This preclinical study suggests that ultrasound is a useful guiding tool for facet joint injections in the cervical spine.
authors.affiliation: Clinic of Neurosurgery, Innsbruck Medical University, 6020 Innsbruck, Austria.
authors.forename: Klaus
authors.initials: K
authors.lastname: Galiano
authors.forename: Alois Albert
authors.initials: AA
authors.lastname: Obwegeser
authors.forename: Gerd
authors.initials: G
authors.lastname: Bodner
authors.forename: Martin Cornelius
authors.initials: MC
authors.lastname: Freund
authors.forename: Hannes
authors.initials: H
authors.lastname: Gruber
authors.forename: Herbert
authors.initials: H
authors.lastname: Maurer
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schatzer
authors.forename: Thomas
authors.initials: T
authors.lastname: Fiegele
authors.forename: Franz
authors.initials: F
authors.lastname: Ploner
mesh_terms: D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D006801:Humans; D007270:Injections, Intra-Articular; D007278:Injections, Spinal / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014463:Ultrasonography / Q000379:methods*; D021801:Zygapophyseal Joint / Q000000981:diagnostic imaging*