Mechanical Aspects of a Single-Bundle Tibial Interference Screw Fixation in a Tendon Graft Acl Reconstruction

Abstract

Numerical methods applicable to the tibia bone and soft tissue biomechanics of an anterior cruciate ligament (ACL) reconstructed knee are presented in this paper. The aim is to achieve a better understanding of the mechanics of an ACL reconstructed knee. The paper describes the methodology applied in the development of an anatomically detailed three-dimensional ACL reconstructed knee model for finite element analysis from medical image data obtained from a computed tomography scan. Density segmentation techniques are used to geometrically define the knee bone structure and the encapsulated soft tissues configuration. Linear and nonlinear elastic constitutive material models are implemented to mechanically characterize the behavior of the biological materials. Preliminary numerical results for the model qualitative evaluation are presented.

Biomechanical Modeling of a Bone Tunnel Enlargement Post ACL Reconstruction

“…The tendon strands were trimmed to the identical size. According to the technique described in a study by Chizari et al [1,11], two same sized tendon strands with a total length of 160 mm were coupled (double-stranded) and folded in half to build a four-strand bundle with a total 80 mm graft length.…”

“…By maintaining the four-tailed end of the tendon bundle, a 10 mm diameter interference screw was screwed into the entrance (anterior aspect) of the tunnel between the tendon strands and moved forward until its tip reached the proximal bone-tunnel opening (Fig.1 c). A general biomechanical test, i.e., tensile test as described previously [14][15][16], was performed on the bone and tendon to observe the placement of the graft and screw in the bone tunnel after the mechanical loading. The loop portion of the tendon hanged with the crosshead of the testing machine, and the bone was secured using custom-made grips in the testing machine (Fig.…”