Histological study of fresh versus frozen semitendinous muscle tendon allografts.

Objective: The purpose of this study was to histologically analyze allografts from cadaveric semitendinous muscle after cryopreservation at -80 degrees C in comparison to a control group kept at only -4 degrees C to test the hypothesis that the histological characteristics of the tissue are maintained when the tendons are kept at lower temperatures.

Methods: In a tissue bank, 10 semitendinous tendons from 10 cadavers were frozen at -80 degress C as a storage method for tissue preservation. They were kept frozen for 40 days, and then a histological study was carried out. Another 10 tendon samples were analyzed while still "fresh".

Results: There was no histological difference between the fresh and frozen samples in relation to seven variables.

Conclusions: Semitendinous muscle tendon allografts can be submitted to cryopreservation at -80 degrees C without suffering histological modifications.