title: An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.
abstract: OBJECTIVE
  To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis.
  
  
  METHODS
  Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints.
  
  
  METHODS
  Cadaveric adult equine forelimbs (n=15 pairs).
  
  
  METHODS
  For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05.
  
  
  RESULTS
  Mean yield load, yield stiffness, and failure load under axial compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation.
  
  
  CONCLUSIONS
  The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue.
  
  
  CONCLUSIONS
  The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.
authors.affiliation: Equine Health Studies Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. gsod@vetmed.lsu.edu
authors.forename: Gary A
authors.initials: GA
authors.lastname: Sod
authors.forename: Laura M
authors.initials: LM
authors.lastname: Riggs
authors.forename: Colin F
authors.initials: CF
authors.lastname: Mitchell
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Hubert
authors.forename: George S
authors.initials: GS
authors.lastname: Martin
mesh_terms: D000818:Animals; D001174:Arthrodesis / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D001696:Biomechanical Phenomena / Q000502:physiology; D001860:Bone Plates / Q000662:veterinary*; D001863:Bone Screws / Q000662:veterinary*; D019245:Compressive Strength / Q000502:physiology; D004868:Equipment Failure / Q000662:veterinary; D005552:Forelimb; D006734:Horse Diseases / Q000503:physiopathology / Q000601:surgery; D006736:Horses / Q000502:physiology / Q000601:surgery*; D066298:In Vitro Techniques; D014033:Toe Joint / Q000502:physiology / Q000601:surgery*; D054159:Torsion, Mechanical