A Tensegrity Model of a Knee for the ACL Reconstruction

Wangdo Kim*

Received: October 06, 2018;   Published: October 22, 2018

DOI: 10.26717/BJSTR.2018.10.001919

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Abstract

Reconstruction of a torn anterior cruciate ligament (ACL) cannot be successful without a properly placed tibial tunnel. Graft impingement occurs when the graft becomes trapped in the notch between the rounded ends of the femur (intercondylar notch) with the knee in extension. A surgical technique for customizing the placement of the tibial tunnel, preventing roof impingement, is presented. For strategies for avoiding graft impingement, surgeons have used two aspects, the anatomy of the ACL and associated landmarks. However, this study showed that the tunnel placement could be determined by the linear combination of two paths of rotational movements of the functional joint. The two lines of paths are referred to as a pair of conjugates and do not belong in the lines of forces in the knee complex, during locomotion.

We are particularly interested in the measuring of our knee proprioception, and of our ability to perceive the change in our position through locating the instantaneous axes of the knee (IAK), that is, the pickup of our movement during locomotion. Using computer modeling of knee kinematic data obtained by MRI scans, we demonstrated a method to determine ideal placement of the tibial tunnel with respect to the IAK. Such placement in vivo has the potential to produce an isokinetic graft without risk of impingement reliably. We present conditions of a non-impingement graft based on the principle of the use of knee tensegrity model. The model introduces the new useful dimensions of sensitivity in foot loading to the knee axis alignment. We demonstrated a method to determine the ideal placement of the tibial tunnel with respect to the IAK. Such placement in vivo has the potential to produce an isokinetic graft without risk of impingement reliably.

Keywords: ACL Reconstruction: Tibial Femoral Tunnel Placement; Graft Impingement; Knee Complex in Involution; Knee Proprioception; Knee Tensegrity System

Abbreviations: IKA: Instantaneous Knee Axis; GRF: Ground Reaction Force; COP: Center of Pressure

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