An inverse dynamics modeling approach to determine the restraining function of human knee ligament bundles

Abstract

Abstract-During knee motion, the fiber bundles of ligaments are nonuniformly loaded in a recruitment pattern which is different for successive knee-joint positions. As a result, the restraining functions of these ligaments are variable. To analyze the relative restraint contributions of the fiber bundles in different knee-joint positions, a new method was developed. Its application was illustrated for the cruciate ligaments of one knee-joint specimen.The methods developed to estimate bundle forces comprise five steps. First, the three-dimensional motions of a knee specimen are measured for anterior-posterior forces, using Rdntgcn Stereophotogrammetric Analysis. Second, bone-ligament-bone tensile tests are performed to evaluate the mechanical properties of these structures in several relative orientations of the bones. Third, multiple fiber bundles are identified in each ligament, based on the main fiber orientations. Fourth, the nonlinear force-length relationship of each functional bundle, as defined by a stiffness and a recruitment parameter, is determined by combining the multidirectional tensile tests with a multiline-element ligament model. Finally, the information obtained is combined in a whole-joint computer model of the knee, to determine the internal forces in the initial kinematic experiment, using an inverse dynamics approach.The technique appeared to be extremely time consuming and technologically involved. However, it was demonstrated to be useful and effective. The preliminary results reveal that the fiber bundle restraints are extremely sensitive to the knee flexion angle and the restraining forces are highly variable within the ligaments. For both cruciate ligaments, a gradual transition was demonstrated in load transfer from the posterior bundles to the more anteriorly positioned ones during knee flexion. Furthermore, it appeared that relatively high forces were carried by only a few fiber bundles at each flexion angle. Based on these preliminary results, it is concluded that the determination of forces in multiple ligament bundles is important for the understanding of failure mechanisms of ligaments. In particular, alternate loading of different fiber bundles suggests that successful operative reconstruc tion of the cruciate ligaments may not be achieved simply by a one-bundle preparation.

Single-incision technique misses the anatomical femoral anterior cruciate ligament insertion: a cadaver study

“…Assuming an anatomical tunnel placement to result in more natural knee kinematics [2,8,20], we tried to reach the center of the femoral anatomical ACL attachment site through a correctly placed tibial tunnel according to Stäubli and Rauschning [24]. This tunnel placement technique respects anatomical structures, starts in the corner medial to the patellar ligament, at the proximal border of the pes anserinus and ventral from the medial collateral ligament, directing the tibial tunnel into the posterior part of the tibial ACL footprint.…”

The natural history of human gait and posture

“…Each supplies substantial fiber bundles with which to resist potentially disruptive external forces, especially anterior and posterior drawer, throughout the joint's flexionextension cycle, and must do so without also compressing the two rigid bodies at any point in the cycle [6]. This is partially accomplished by a spiraling or twisting of each cruciate's various fiber bundles between their femoral and tibial points of attachment, a construction that results in separate portions of each ligament being sequentially taut at different points within the flexion-extension cycle [10][11][12][13][14][15]. This can be demonstrated by X-ray stereophotogrammetry [16], dissection [14], and by forced separation of fresh whole joints in which only one cruciate has been kept intact [17].…”

Anterior Cruciate Ligament Reconstruction With Double Bundle Versus Single Bundle: Experimental Study

“…[4][5][6][7][8][9][10] However, it is known that the ACL has at least 2 anatomical bundles, the small anteromedial one and the posterolateral one, and that their mechanical and functional performances are different. 1,3,5,[10][11][12][13][14][15][16][17] The double tunnel technique in humans has been reported, with good results. 20,[22][23][24] However, most studies consist either of case series reports with no comparative control groups or of mere descriptions of the technique, such as technical notes.…”