Effects of freezing/thawing on the biomechanical properties of human tendons

Numerous biomechanical studies using osteoarticular complex need frozen cadaveric specimens. Some of these studies deal with the resistance of the tendinous structures, for example the resistance of some autografts, such as the patellar ligament and the semitendinosus and gracilis tendons for reconstruction of the anterior cruciate ligament. The aim of this study was the in-vitro evaluation of the mechanical modifications induced by freezing/thawing on human tendons. The long head of the biceps brachii tendon was used as the reference. Eight pairs of tendons of the long head of the biceps brachii were taken from eight fresh cadavers. After drawing lots, one was tested immediately, the other was deep-frozen and then thawed. With an Instron material-testing machine, we performed a relaxation test and a uniaxial tensile test, to estimate the ultimate tensile failure and the elastic modulus of each pair of tendons. Freezing had no influence on the tendinous relaxation, but altered significantly the ultimate tensile failure and Young's modulus of the tendons.