The biomechanical properties of human fresh-frozen vs thiel embalmed foot tendons

Abstract

Background: The aim of this study was to directly compare the effects of Thiel embalming on the mechanical properties of three human tendons to similar tendons from the fresh-frozen, ipsilateral foot of the same cadavers. Method: Following pre-conditioning, biomechanical tensile tests were conducted on tibialis anterior, peroneus longus and Achilles tendons at a strain rate of 5 mm/minute, using an optical extensometer for the direct measurement of sample strain. Results: Qualitatively, all tested tendons exhibited similar mechanical behaviour characterised by an initial toe region followed by a region of linear behaviour. Quantitatively, however, averaging the results for the three cadaveric samples revealed consistent differences across all tendons in the case of unloading stiffness. Conclusion: Thiel embalming method is suitable for preservation of human tendons, with embalmed tendons appearing to have similar mechanical behaviour compared to their fresh frozen counterparts. Although quantitative differences do exist, these do not disprove the use of Thiel embalmed tendons in comparative studies once care is exercised when utilizing these for biomechanical testing. However, in vitro results used to infer in vivo function should always be treated with caution.