title: Computed tomography to identify preoperative guidelines for internal fixation of the distal sesamoid bone in horses: an in vitro study.
abstract: OBJECTIVE
  To assess the reliability of computed tomography (CT) to identify the direction of implant insertion for cortical screws along the longitudinal axis of intact (nonfractured) distal sesamoid bones.
  
  
  METHODS
  In vitro study.
  
  
  METHODS
  Cadaveric paired equine forelimbs (n=16).
  
  
  METHODS
  Insertion of a cortical screw in lag fashion along the longitudinal axis of intact (nonfractured) distal sesamoid bones was evaluated in 2 groups (3.5 and 4.5 mm) of 8 paired limbs. In each group, the direction of the distal sesamoid bone was determined by CT (Equine XTC 3000 pQCT scanner). Screw placement was verified by specimen dissection. Implant direction was considered satisfactory if the entire screw length was within the distal sesamoid bone and not damaging the articular or flexural surfaces.
  
  
  RESULTS
  In our sample and according to our criteria, the proportion of satisfactory direction of screws was 0.63 (5/8) for 4.5 mm implants, and 0.87 (7/8) for 3.5 mm implants.
  
  
  CONCLUSIONS
  CT is a useful imaging modality to identify anatomic landmarks for insertion of a 3.5 mm cortical screw in the distal sesamoid bone.
authors.affiliation: Clinique Equine Desbrosse, St. Lambert-des-Bois, France.
authors.forename: Roland
authors.initials: R
authors.lastname: Perrin
authors.forename: Thomas
authors.initials: T
authors.lastname: Launois
authors.forename: Laurent
authors.initials: L
authors.lastname: Brogniez
authors.forename: Francis G
authors.initials: FG
authors.lastname: Desbrosse
authors.forename: Richard P
authors.initials: RP
authors.lastname: Coomer
authors.forename: Peter D
authors.initials: PD
authors.lastname: Clegg
authors.forename: Ayalu A
authors.initials: AA
authors.lastname: Reda
authors.forename: Simon G
authors.initials: SG
authors.lastname: Gehin
authors.forename: Jean-Michel E
authors.initials: JM
authors.lastname: Vandeweerd
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001863:Bone Screws / Q000662:veterinary; D005552:Forelimb / Q000293:injuries / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D006734:Horse Diseases / Q000601:surgery*; D006736:Horses; D016268:Internal Fixators / Q000662:veterinary; D017410:Practice Guidelines as Topic; D012716:Sesamoid Bones / Q000293:injuries / Q000601:surgery*; D014057:Tomography, X-Ray Computed / Q000662:veterinary*; D016896:Treatment Outcome