Twenty limbs from 6 cadavers (4 complete limb sets, 2 partial sets—total of 4 forelimb and 6 hindlimb pairs) were evaluated.
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.
Thus, Acutrak-Plus® screws may provide an alternative means of fixation for proximal interphalangeal joint arthrodesis.
Source: RYAN R. E. WOLKER, JAMES L. CARMALT, DAVID G. WILSON (2009): 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. In: Veterinary Surgery
Volume 38 Issue 7, Pages 861 - 867
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