title: A mechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial locking compression plate and two abaxial transarticular cortical screws versus an axial dynamic compression plate and two abaxial transarticular cortical screws.
abstract: OBJECTIVE
  To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow locking compression plate (ELCP) using 5.0 mm locking screws and 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (ELCP-TLS) with 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) for equine proximal interphalangeal (PIP) joint arthrodesis.
  
  
  METHODS
  Experimental.
  
  
  METHODS
  Cadaveric adult equine forelimbs (n = 18 pairs).
  
  
  METHODS
  For each forelimb pair, 1 PIP joint was stabilized with an axial ELCP using 5.0 mm locking screws and 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 PIP joint 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. Six matching pairs of constructs were tested in single cycle to failure under axial compression, 6 construct pairs were tested for cyclic fatigue under axial compression, and 6 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, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the LCP-TLS fixation. There was no significant difference between the mean number of cycles to failure in axial compression of the LCP-TLS and the DCP-TLS fixations. Mean yield load, yield stiffness, and failure load under torsion, single cycle to failure, of the LCP-TLS fixation were significantly greater than those of the DCP-TLS fixation.
  
  
  CONCLUSIONS
  The DCP-TLS construct provided significantly greater stability under axial compression in single cycle to failure than the ELCP-TLS construct, the ELCP-TLS construct provided significantly greater stability under torsional loading in single cycle to failure than the DCP-TLS construct, and there was no significant difference in stability between the 2 constructs for cyclic loading under axial compression.
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: George S
authors.initials: GS
authors.lastname: Martin
mesh_terms: D000818:Animals; D001174:Arthrodesis / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D001696:Biomechanical Phenomena; D001860:Bone Plates / Q000662:veterinary*; D001863:Bone Screws / Q000662:veterinary*; D019245:Compressive Strength; D006736:Horses / Q000601:surgery*; D066298:In Vitro Techniques; D055595:Mechanical Phenomena; D014033:Toe Joint / Q000502:physiology / Q000601:surgery*; D054159:Torsion, Mechanical; D016474:Weight-Bearing