2015 ISAKOS Biennial Congress ePoster #303

The Effect of Donor Age on the Structural and Mechanical Properties of Allograft Tendons

Jason L. Dragoo, MD, Redwood City, CA UNITED STATES
Anthony Behn, MS, Palo Alto, CA UNITED STATES
Kat Swank, MD, Palo Alto, CA UNITED STATES

Stanford University, Palo Alto, CA, USA

FDA Status Not Applicable

Summary: Age explained at most 6% of the variation in structural and mechanical properties of tibialis posterior allograft tendons

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Abstract:

Background

Allograft tendons are commonly used in surgical ligament reconstruction. While it is commonly accepted that donor age will affect mechanical properties of graft tissue, the apparent age threshold is unknown.

Purpose

It was hypothesized that donor age would have no effect on structural and mechanical properties of tibialis posterior allograft tendons.

Methods

Five hundred and fifty allograft posterior tibialis tendons were examined. Linear stiffness, ultimate tensile force, ultimate displacement, tensile modulus, ultimate tensile strength, and ultimate tensile strain were calculated for specimens in each of six age groups: 15-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years old. Both first and second order polynomial regressions were performed to determine the correlation between structural and mechanical properties and age. Welch ANOVAs with Games-Howell post hoc tests were performed to facilitate comparisons among age groups.

Results

All parameters displayed a weak correlation with age, with the highest R2 term being 0.063 for ultimate tensile strength. Linear stiffness, ultimate tensile force, and tensile modulus displayed almost no correlation with age. Ultimate tensile strength increased slightly with age up to age 40-50 and then decreased with further increases in age. Slight decreases in ultimate displacement and ultimate tensile strain were observed with increasing age. Numerous statistically significant differences were observed between age groups for each outcome parameter; however, the magnitudes of the differences between age groups are relatively small (less than 15%) for all outcome parameters.

Conclusion

Age explained at most 6% of the variation in structural and mechanical properties of tibialis posterior allograft tendons.