前十字靭帯付着部に対する張力の作用方向と作用位置

抄録

In the present study, the direction and point of application of the tensile force carried by the anterior cruciate ligament (ACL) were analyzed with respect to the femoral and tibial attachments. Porcine knee joints (n=4) were fixed to a 6-DOF robotic system at full extension, 60°, and 90° of flexion. The ACL force in response to a 100 N anterior tibial load was analyzed under the assumption of superposition. After the tests, 10 points randomly selected on the femoral and tibial attachments' boundaries were 3-dimensionally digitized. The centroid of the attachment areas, connecting line between the femoral and tibial centroids (centroid line), and attachment plane were analyzed. In addition, the intersection and angle between the force line and the attachment plane, the angle between the centroid line and the attachment plane, and the angle between the force line and centroid line were analyzed. As a result, there were differences in the angles formed by the force line and the angles formed by the centroid line at all flexion angles. The intersection of the force line was located posteriorly to the centroid in the femoral attachment. These results indicate that the ACL are bent due to fiber impingement to the femoral condyle. The angle between the force line and centroid line was smaller at the full extension than at flexion, suggesting that the fiber bending becomes smaller in the full extension.