Journal of Orthopaedic Research

C.D. Harner, G.A. Livesay, S. Kashiwaguchi, H. Fujie, N.Y. Choi and S.L-Y. Woo


As an important step towards determining cruciate ligament function, the cross-sectional shapes and areas of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL) and menisco-femoral ligament (MFL) were evaluated in situ within the same knee using a laser micrometer system. Measurements were made in 8 human cadaver specimens at 5 levels along the midsubstance of each ligament, with the knee at 0*, 30*, 60* and 90* of flexion. The PCL was found to be widest in the medial-lateral direction, whereas the ACL was usually larger in the anterior-posterior direction. Of the cruciate ligaments, the ACL cross-sectional shapes were noted to be generally more circular along the entire midsubstance relative to the PCL. In contrast, the cross-sectional shapes of the PCL were more circular near the tibia, becoming progressively more elongated towards the femur. MFLs were more circular than the other two ligaments, with an occasional medial-lateral widening similar to that of the PCL. The cross-sectional area of both the cruciate ligaments changed along the length of the midsubstance, with the ACL becoming slightly larger distally, and the PCL enlarging proximally. Knee flexion angle was not found to have a significant effect on the cross-sectional areas of the ligaments, but was noted to alter the cross-sectional shapes. For direct within specimen comparison, the cross-sectional area of the PCL was approximately 150% larger than that of the ACL at the proximal and midsubstance levels, but only 120% larger at the most distal level. Meniscofemoral ligaments possessed approximately 22% the total cross-sectional area of the PCL.