THE BIOMECHANICAL STUDY of DIFFERENT POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION TECHNIQUES

The main purpose of our study was to evaluate the biomechanics of different posterior cruciate ligament (PCL) reconstruction techniques. Seven fresh cadaver knees were collected. A 6-DOF robot arm was used to test the biomechanical parameters, including the posterior stability, the lateral stability and the rotation stability of different PCL reconstruction techniques. Each group was tested at the knee flexion of 0, 30, 60, 90 and 120, under the following conditions respectively: a posterior force of 134N, an internal and external rotation torque of 5N.m, a varus and valgus torque of 10N.m, and a combination of 100N posterior force and 5N.m external rotation torque. The posterior tibia translation and the rotational angle of the 4-tunnel double-bundle PCL reconstruction group were significantly lower than that of 3-tunnel double-bundle group and the single-bundle group; the posterior tibia translation valgus-varus-angle were lower at some specified flexion angle. No statistical difference was found between the anatomic 4-tunnel bundle group and the intact knee group concerning the posterior tibia translation, the rotational angle, and the valgus-varus-angle. This study showed that the biomechanics of PCL of 4-tunnel double-bundle reconstruction was closer to the intact knees than the other two reconstruction methods.