title: Comparison of open reduction versus minimally invasive surgical approaches on screw position in canine sacroiliac lag-screw fixation.
abstract: OBJECTIVE
  To compare accuracy and consistency of sacral screw placement in canine pelves treated for sacroiliac luxation with open reduction and internal fixation (ORIF) or minimally invasive osteosynthesis (MIO) techniques.
  
  
  METHODS
  Unilateral sacroiliac luxations created experimentally in canine cadavers were stabilized with an iliosacral lag screw applied via ORIF or MIO techniques (n = 10/group). Dorsoventral and craniocaudal screw angles were measured using computed tomography multiplanar reconstructions in transverse and dorsal planes, respectively. Ratios between pilot hole length and sacral width (PL/SW-R) were obtained. Data between groups were compared statistically (p <0.05).
  
  
  RESULTS
  Mean screw angles (±SD) were greater in ORIF specimens in both transverse (p <0.001) and dorsal planes (p <0.004). Mean PL/SW-R was smaller (p <0.001) in the ORIF group, yet was greater than 60%. While pilot holes exited the first sacral end-plate in three of 10 ORIF specimens, the spinal canal was not violated in either group.
  
  
  CONCLUSIONS
  This study demonstrates that MIO fixation of canine sacroiliac luxations provides more accurate and consistent sacral screw placement than ORIF. With proper techniques, iatrogenic neurological damage can be avoided with both techniques. The PL /SW-R, which relates to safe screw fixation, also demonstrates that screw penetration of at least 60% of the sacral width is achievable regardless of surgical approach. These findings, along with the limited dissection needed for accurate sacral screw placement, suggest that MIO of sacroiliac luxations is a valid alternative to ORIF.
authors.affiliation: Loic M. Dejardin, DCM, MS, DACVS, DECVS, Michigan State University, College of Veterinary Medicine, 736 Wilson Road, East Lansing, MI 48824-1314, United States, E-mail: Dejardin@cvm.msu.edu.
authors.forename: Loïc M
authors.initials: LM
authors.lastname: Déjardin
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Marturello
authors.forename: Laurent P
authors.initials: LP
authors.lastname: Guiot
authors.forename: Reunan P
authors.initials: RP
authors.lastname: Guillou
authors.forename: Charles E
authors.initials: CE
authors.lastname: DeCamp
mesh_terms: D000818:Animals; D001863:Bone Screws / Q000662:veterinary*; D002102:Cadaver; D004285:Dogs / Q000293:injuries / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000379:methods / Q000662:veterinary*; D004204:Joint Dislocations / Q000601:surgery / Q000662:veterinary*; D007593:Joint Instability / Q000662:veterinary; D019060:Minimally Invasive Surgical Procedures / Q000379:methods / Q000662:veterinary*; D000070799:Open Fracture Reduction / Q000379:methods / Q000662:veterinary*; D012446:Sacroiliac Joint / Q000293:injuries / Q000601:surgery*
keywords: Sacroiliac luxation; fluoroscopy; lag screw fixation; minimally invasive osteosynthesis; sacroiliac fracture