Biomechanical research of different tibia tunnel in posterior cruciate ligament reconstruction

Objective To perform a biomechanical study for evaluation of the failure rates of PCL grafts which reconstructed with 3 different angles of tibia tunnels in cadaveric knees.Methods Eighteen cases of Achilles tendons were used to reconstruct the posterior cruciate ligament on the cadaveric tibia.According to different angles between the tunnels and the tibial platforms,the spices were divided into 3 groups: A(30 degrees),B(40 degrees),C(50 degrees).Cyclic load tests were conducted to evaluate the failure rates of the PCL grafts.The area of tibia tunnels and pressures on tibia tunnels were measured before and after cyclic load tests.Results The angle between tibia tunnel and tibial platform had the positive correlation with the graft failure strength.Group C had the minimum pressures on the tibia tunnels,the minimum changes of the measures of area of tibial tunnels,and the biggest failure strength.Conclusion Increasing the angel of the tunnel and the tibial platform could reduce the killer turn effect with advantage of graft failure strength.