Effect of cryoprotectant incubation time on handling properties of allogeneic tendons prepared for knee ligament reconstruction.

Soft tissue tendon allografts prepared for anterior cruciate ligament reconstruction are becoming increasingly popular; although concerns exist regarding increased long-term laxity and traumatic rupture rates. This qualitative study evaluated the tissue handling properties of human tibialis posterior tendons prepared using a patented process to improve allograft remodeling and ligamentization under differing cryoprotectant incubation times over 60-min rehydration. Tendons that had been incubated for 8 h had smaller diameters than those that were incubated for 2 h (8.5 +/- 1.5 mm vs. 9.1 +/- 1.3 mm, p = 0.02). Qualitative tissue handling property results indicated that the 8-h incubation had a negative affect on tissue color. Both incubation time and rehydration time influenced tensile stiffness, compressive resilience, and ease of tissue handling for allograft preparation with the 8-h group displaying poorer results. This study concludes that an 8-h cryoprotectant incubation time is detrimental to qualitative allogeniec tibialis posterior tendon properties. Both groups tended to improve with longer rehydration times, however the 8-h incubation group remained actively dehydrated as evidenced by its smaller diameter and poorer tissue handling properties. Suboptimally rehydrated tendons would be more likely to accrue damage during allograft preparation or during implantation.