Introduction: Tendinous lesions are common in horses with the DDFT commonly injured. Acoustoelastograghy
(AEG) is a new ultrasonographic technique that evaluates tissue strain based on changes
in tissue length when an external force is applied. The purpose of this study was
to evaluate AEG and biomechanical properties of the DDFT. Due to the differences in
weight distribution between forelimb and hindlimb and the morphological change between
the proximal (cylindrical) and distal (ribbon-like) appearance of the DDFT, we hypothesized
that differences would exist in AEG parameters among these limbs and locations.
Materials and Methods: Eight horses were sedated and subsequently euthanatized for reasons unrelated to
the study. Cineloops of DDFTs transitioning through the loading phase of the limb
were made in vivo and then after harvesting tendons ex vivo. Software was then used
to determine the strain of the tendons via AEG.
Results: A two-way ANOVA with limb and location as factors was performed along with linear
regression. A p-value < 0.05 was considered significant. For maximal strain, there were significant
differences between proximal and distal regions (p < 0.001) but no significant differences were identified between fore and hindlimbs.
Discussion/Conclusion: During loading movements in vivo, the DDFT is subjected to translation and strain
underneath the skin in relation to the transducer; ex vivo, the transducer only identifies
pure strain. These data indicate that biomechanical function of the DDFT changes from
the proximal and distal regions and the caution should be used when making inferences
between ex vivo and in vivo data.
Acknowledgement: Supported by a grant from the Surgical Translation and Research Laboratory, UF.
