An In Vitro Biomechanical Comparison of Equine Proximal Interphalangeal Joint Arthrodesis Techniques: Two Parallel Transarticular Headless Tapered Variable Pitch Screws Versus Two Parallel Transarticular AO Cortical Bone Screws Inserted in Lag Fashion

Authors
Timm Gudehus Dr med vet, Gary A. Sod DVM, PhD, Laura M. Riggs DVM, PhD, Diplomate ACVS, Colin F. Mitchell BVMS, MS, Diplomate ACVS, George S. Martin DVM, MS, MBA, Diplomate ACVS
Date
April 2011
Journal
Veterinary Surgery
Volume
40
Number
3
Pages
261-265

Objectives: To compare the mean number of cycles to failure under axial compression of equine proximal interphalangeal (PIP) joint arthrodesis constructs created by 2 parallel transarticular Acutrak Plus screws (AP-TS) or 2 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (AO-TLS).

Study Design: Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints.

Sample Population: Cadaveric adult equine forelimbs (n=5 pairs).

Methods: For each forelimb pair, 1 PIP joint was stabilized with AP-TS and 1 with AP-TLS. The 5 construct pairs were tested for cyclic fatigue under axial compression. Mean number of cycles to failure for each fixation method were compared by a paired t-test within each group with statistical significance set at P<.05.

Results: The mean number of cycles to failure under axial compression for AO-TLS fixation and AP-TS fixation were 57,723±8488 and 35,322±4698, respectively.

Conclusion: The AO-TLS was superior to the AP-TS in resisting cyclic fatigue under axial compression.