Get access

Arthrodesis of the Equine Proximal Interphalangeal Joint: A Biomechanical Comparison of Two Parallel Headless, Tapered, Variable-Pitched, Titanium Compression Screws and Two Parallel 5.5 mm Stainless-Steel Cortical Screws

Authors

  • RYAN R. E. WOLKER DVM, MVetSc,

    1. Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
    Search for more papers by this author
  • JAMES L. CARMALT MA, VetMB, MVetSc, Diplomate ABVP & ACVS,

    1. Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
    Search for more papers by this author
  • DAVID G. WILSON DVM, Diplomate ACVS

    1. Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
    Search for more papers by this author

Corresponding author: Ryan R. E. Wolker, DVM, Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5B4. E-mail: rrw928@mail.usask.ca.

Abstract

Objective— To compare the biomechanical characteristics, failure mode, and effects of side (left or right limb) and end (forelimb or hindlimb) of different screws in 2-screw, parallel-screw proximal interphalangeal joint arthrodesis constructs in horses.

Study Design— In vitro experimental study.

Sample Population— Twenty limbs from 6 cadavers (4 complete limb sets, 2 partial sets—total of 4 forelimb and 6 hindlimb pairs).

Methods— Two parallel 5.5 mm cortical (AO) screws were inserted in lag fashion in 1 randomly allocated limb of a pair, and 2 parallel headless, tapered, variable-pitched, titanium compression screws (Acutrak-Plus®) were inserted in the contralateral limb. Constructs were tested in 3-point bending in a dorsopalmar (plantar) direction using a materials-testing machine at a loading rate of 5.83 mm/s. Maximal bending moment at failure and composite stiffness were calculated from data generated on load–displacement curves. Data were analyzed using a Friedman 2-way analysis of variance and Wilcoxon's signed-rank tests.

Results— No significant difference was detected for bending moment or stiffness values in proximal interphalangeal joint arthrodesis constructs using 2 parallel Acutrak-Plus® or AO screws for fixation. Mean stiffness values were significantly different between forelimb and hindlimb constructs.

Conclusions— Performance of 2 parallel Acutrak-Plus® screws was biomechanically comparable with 2 parallel AO 5.5 mm cortical screws in in vitro pastern arthrodesis constructs.

Clinical Relevance— Acutrak-Plus® screws may provide an alternative means of fixation for proximal interphalangeal joint arthrodesis.

Get access to the full text of this article

Ancillary