title: Clinical use of computed tomography and surface markers to assist internal fixation within the equine hoof.
abstract: OBJECTIVE
  To describe clinical use of computed tomography (CT) and hoof surface markers to facilitate internal fixation within the confines of the hoof wall.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Horses (n = 16) that had CT-guided internal fixation of the distal phalanx (DP) or distal sesamoid bone (DSB).
  
  
  METHODS
  Drill bit entry point and direction were planned from CT image series performed on hooves with grids of barium paste dots at proposed entry and projected exit sites. Post-implantation CT images were obtained to check screw position and length as well as fracture reduction. Imaging, reduction, and surgical and general anesthesia times were evaluated. Outcome was recorded.
  
  
  RESULTS
  Screw position and length were considered near optimal in all horses, with no consequential malposition of bits or screws. Fracture reduction was evident in all cases. Preoperative planning times (at least 2 CT image acquisitions and grid creation) ranged from 10 to 20 minutes. Surgery time ranged from 45 to 90 minutes (mean, 61 minutes) and general anesthesia time ranged from 115 to 220 minutes (mean, 171 minutes).
  
  
  CONCLUSIONS
  The combination of CT and surface marker grids allowed accurate positioning of screws in clinical DP and DSB fractures. The technique was simple and rapid. An aiming device is useful for the technique.
authors.affiliation: Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania.
authors.forename: Janik C
authors.initials: JC
authors.lastname: Gasiorowski
authors.forename: Dean W
authors.initials: DW
authors.lastname: Richardson
mesh_terms: D000818:Animals; D001863:Bone Screws / Q000662:veterinary; D005260:Female; D005552:Forelimb / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000379:methods / Q000662:veterinary*; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000601:surgery / Q000662:veterinary; D006614:Hindlimb / Q000601:surgery; D006724:Hoof and Claw / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D006736:Horses / Q000293:injuries* / Q000601:surgery; D008297:Male; D012189:Retrospective Studies; D012716:Sesamoid Bones / Q000293:injuries; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary*; D016896:Treatment Outcome