Purpose: The use of allografts for anterior cruciate ligament (ACL) reconstruction has gained increased popularity. The major benefits of allograft for ACL replacement include decreased morbidity, easier patient rehabilitation and include ease of surgical procedure, decreased harvest site morbidity and easier patient rehabilitation. Further, allografts have improved appeal because of better sterilization techniques, improve graft availability and decreased hospital costs.|The objective of this study was to perform mechanical testing on various types of allograft. Specimens for allograft reconstruction of the anterior cruciate ligament included tibialis anterior tendon, tibialis posterior tendon, Achilles tendon and bone patella tendon tissues

Methods: The allografts tested were used for deployment in patients suffering with anterior cruciate ligament disruptions. A total of fifty grafts were analyzed. The breakdown of graft types included 15 tibialis anterior tendon, 15 tibialis posterior tendon, 10 Achilles tendon and 10 bone patella tendon tissues. The test techniques included: cutting the tendons to a set thickness and length. The tendons were then mounted in a cryogrip and frozen with liquid Nitrogen to below zero. They were mounted into a servo-hydraulic testing machine and pre-loaded and pre-conditioned. The specimens were then stretched to failure at a set strain rate.

Results: No difference was found between the mechanical/material properties of the various tendon allografts – these included tensile strength and a high stress linear modulus assessments. The mechanical (structural properties) of the allografts were more dependant on the cross sectional area of the allograft than the type of allograft tissue.The greater the cross-sectional area of the allograft, the greater the strength and stiffness of the graft.

Conclusions: These findings have considerable clinical applicability in choosing an allograft for anterior cruciate ligament reconstruction.