Abstract
The purpose of this study is to biomechanically compare Evolgate and Intrafix using cyclic loading with final pull-out tests. Five pairs of double looped bovine digital extensor tendons and 10 porcine tibias were used. We evaluated the displacement at 1, 10, 100, 250, 500, 1000 and 1500 cycles. We used cyclic tests (1500 cycles between 50 and 200 N with final pull-out). Biomechanical tests were performed with use of a Zwick-Roell Z010 mechanical testing machine (Zwick-Roell, Germany), and the testing data were recorded with the accompanying software package (Testexpert 8.1, Zwick-Roell). A paired t-test was performed for statistical evaluation. There was no statistically significant difference in slippage between the two devices. The mean ultimate failure load at pull-out after 1500 cycles was 832±156 N for Intrafix and 1058±130 N for the Evolgate.The mean stiffness at pull-out was 269±86 for Intrafix and 247±44 for the Evolgate, and there were no statistically significant differences (p> 0.05). At statistical evaluation there was a difference in ultimate failure load between the IF and the EV (p< 0.05). Although further studies are needed to investigate bone growth into the tibia tunnel, Evolgate seems to be a good choice for tibial fixation of hamstring tendons. Moreover, Evolgate has higher values of strength than Intrafix.
