33rd Annual Scientific Meeting proceedings

Introduction

Bioabsorbable screws already used in human medicine were not tested jet before for equine use. The goal of this study was to to compare the pullout strength of absorbable  INION FreedomScrew™ with conventional  cortical Synthes screws.

  Materials and Methods

Ten pairs of forelimbs from different breeds and ages (2-25) of horse cadavers underwent fracture simulation and repair.

During the experiment, an artificially formed sagittal fracture of the proximal phalanges of twenty forlimbs of ten cadavers was fixed with ten metal and ten absorbable screws. Using the corresponding metacarpus for each proximal phalanx as a wedge. Biomechanical pressure tests were carried out with the Zwickk Z250 computer-controlled universal material testing machine. During the test, steadily increasing pressure was applied to the metacarpal wedge until a 20% drop was detected in terms of resistance. Maximum applied force (N), and the extent of fracture opening (mm) during compression was evaluated.

  Results

Based on statistical analysis, we can say that the average pullout strength of the bioabsorbable screws was 61.71% (7895.24 N ) of the metal medical screws. Opening dimensions were the same in both cases, t = 0.013849, df = 7, p-value = 0.9893, and the mean difference was 0.004311 mm.

 Discussion

Bioabsorbable screws have the advantage of full adaptation to inserted bone based on the literature, however they are much inferior and not adviced for use in proximal phalangeal fractures.