title: Comparison of two ultrasound-guided injection techniques targeting the sacroiliac joint region in equine cadavers.
abstract: OBJECTIVE
  To compare the accuracy and distribution of injectate for cranial (CR) and caudomedial (CM) ultrasound-guided injections of equine sacroiliac joints.
  
  
  METHODS
  Both sacroiliac joints from 10 lumbosacropelvic specimens were injected using cranial parasagittal (CR; curved 18 gauge, 25 cm spinal needles) and caudomedial (CM; straight 18 gauge, 15 cm spinal needles) ultrasound-guided approaches. Injectate consisted of 4 ml iodinated contrast and 2 ml methylene blue. Computed tomographical (CT) scans were performed before and after injections. Time for needle guidance and repositioning attempts were recorded. The CT sequences were analysed for accuracy and distribution of contrast.
  
  
  RESULTS
  Intra-articular contrast was detected in sacroiliac joints following 15/40 injections. The CR and CM approaches deposited injectate ≤2 cm from sacroiliac joint margins following 17/20 and 20/20 injections, respectively. Median distance of closest contrast to the sacroiliac joint was 0.4 cm (interquartile range [IQR]: 1.5 cm) for CR approaches and 0.6 cm (IQR: 0.95 cm) for CM approaches. Cranial injections resulted in injectate contacting lumbosacral intertransverse joints 15/20 times. Caudomedial injections were perivascular 16/20 times.
  
  
  CONCLUSIONS
  Safety and efficacy could not be established.
  
  
  CONCLUSIONS
  Cranial and CM ultrasound-guided injections targeting sacroiliac joints were very accurate for periarticular injection, but accuracy was poor for intra-articular injection. Injectate was frequently found in contact with interosseous sacroiliac ligaments, as well as neurovascular and synovial structures in close vicinity of sacroiliac joints.
authors.affiliation: John David Stack, MVB, MSc, MRCVS, University College Dublin Veterinary Hospital, Belfield, Dublin 4, Ireland, Phone: +353 8604 33 088, E-mail: davestackvet@hotmail.com.
authors.forename: John David
authors.initials: JD
authors.lastname: Stack
authors.forename: Chiara
authors.initials: C
authors.lastname: Bergamino
authors.forename: Ruth
authors.initials: R
authors.lastname: Sanders
authors.forename: Ursula
authors.initials: U
authors.lastname: Fogarty
authors.forename: Antonella
authors.initials: A
authors.lastname: Puggioni
authors.forename: Clodagh
authors.initials: C
authors.lastname: Kearney
authors.forename: Florent
authors.initials: F
authors.lastname: David
mesh_terms: D000818:Animals; D006736:Horses; D007270:Injections, Intra-Articular / Q000379:methods / Q000662:veterinary*; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000662:veterinary; D018084:Ultrasonography, Interventional / Q000379:methods / Q000662:veterinary*
keywords: Ultrasound-guided; computed tomography; horse; lumbosacral; sacroiliac