Finite element study on the anatomic transtibial technique for single-bundle anterior cruciate ligament reconstruction

Abstract

The anatomic transtibial (TT) technique is proposed as a new approach for single-bundle anterior cruciate ligament (ACL) reconstruction. Geometric models of the anatomic TT and anteromedial (AM) portal techniques were fabricated with a reconstructed knee joint model and virtual surgical operations. Grafts of 7 mm diameter were modeled and inserted into tunnels drilled in each model. In the models, the shape of the graft between the femur and the tibia, the lengths of the bone tunnels, and the femoral graft bending angles were evaluated. To evaluate the biomechanical effects of both techniques on the grafts, the contact pressures and maximum principal stresses in the grafts were calculated using the finite element method. The anatomic TT technique placed the femoral tunnel to the anatomic position of the native ACL femoral attachment site. In addition, it decreased the peak contact pressure and the maximum principal stress at the full extension position of the graft compared with the AM portal technique. The anatomic TT technique may be regarded as a superior surgical technique compared with the conventional TT and AM portal techniques. Because of the easy surgical operation involved, the technique decreases the operation time for ACL reconstruction and it provides a deformation behavior of grafts similar to that in the native ACL in a knee joint. With its few side effects, the anatomic TT technique may considerably help patients.

Effect of femoral tunnel positions on graft stress in outside‐in ACL reconstruction surgery during continuous knee motion: A simulation study

“…Existing studies are known to have the limitation of being conducted with static experiments and computational analyses at certain angles without reproducing continuous knee movements . However, the present study was intended to implement the movements of actual knees along the actual path through dynamics analysis.…”

“…The experimental method used in most optimal position studies, however, set up specific angles for non‐continuous movements of the knee joint (0, 30, 45, 60, 90 degrees) instead of continuous movements. This type of experiment has the shortcoming of being unable to ensure continuity of the knee joint motion in in vivo environments . Since optimal femoral tunnel starting points cannot be easily found through a small number of cadaver experiments, attempts to overcome problems through computational analyses have been increasing.…”

A Review on Finite Element Modeling and Simulation of the Anterior Cruciate Ligament Reconstruction

“…This study used the validated FE model developed in Suggs et al (2003). Bae et al, 2016 Evaluation of the tunnel position and shape, the bending angles of graft and the biomechanical effects on the grafts utilizing either an anatomic transtibial or anteromedial portal technique.…”

“…As concerns the process of producing the tunnels for the grafts, it can be accomplished via Boolean operations with twisted cylinders so as to closely mimic the surgical intervention. As an indicative methodology, the anatomic transtibial technique implemented by Bae et al (2016) is briefly analyzed here, where a single-bundle methodology was adopted. Firstly, the femur was rotated from 30 • of flexion to 75 • and then a 4 mm anterior translation was imposed.…”

“…The initial FE modeling set-up is illustrated in Figure 5A. In particular, two steps are usually used to simulate ACLR (see for example, Bae et al, 2016). In the first step, the end graft area of the femur is fixed, while, regarding the corresponding graft area of the tibia, an initial tension is applied, which is aligned with the outwardfacing unit normal vector of the graft cross section.…”