Cruciate Ligament Reconstruction Analysis of Knee Kinematics and Graft In Situ Forces

Cadaveric studies have demonstrated that various PCL reconstruction techniques are able to restore knee biome-chanics at the time of initial fixation.11,16,17,24 Clinical stud-ies, however, have not consistently shown restoration of normal posterior knee laxity, especially in patients with chronic tears of the PCL.15,20,22 In an attempt to improve the efficacy of current PCL reconstruction techniques, numerous studies have addressed issues such as tunnel placement, graft selection and length, and tensioning con-ditions.4,5,9,12,17,23,27 The method of fixing the graft to the tibia is a specific variable of recent interest. The standard, most widely applied technique uses a tibial tunnel to facil-itate graft fixation to the anterior aspect of the tibia. In this transtibial reconstruction, the PCL graft makes a sharp turn as it exits the proximal margin of the tibial tun-nel, passes over the posterior aspect of the tibial plateau, and approaches the femoral tunnel. This acute bend in the graft poses several potential disadvantages. Both the excessive bending of the graft and the abrasive ridge of the proximal tibial tunnel margin may theoretically increase graft tissue strain and friction. This increased strain and friction could potentially contribute to graft elongation after fixation, graft fraying or failure at the sharp proximal tibial tunnel, and inadequate pretension.1 These factors, among others such as posterolateral instability, may con-tribute to the residual posterior knee laxity observed clin-ically after traditional transtibial reconstruction.15,20,22,3