Related Experiment Video
Updated: May 11, 2026

Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum (TOLF) Using Ultrasonic and Conventional Osteotomes
Published on: April 21, 2023
Characterization of the orientation and isometry of Humphrey's ligament
Michael B Cross1, Bradley S Raphael, Travis G Maak
1Hospital for Special Surgery, 535 E 70TH ST, New York, NY 10021, United States.
Objectives/Purpose:
The purpose of this study was to examine the effect of flexion angle on isometry and fiber obliquity of the anterior meniscofemoral ligament (Humphrey's ligament (HL)).
Methods:
Following a medial parapatellar arthrotomy on 7 fresh frozen cadavers, the insertion points of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, and HL were identified. Using a 9mm circular software tool, virtual fibers were created. Within each virtual graft, a central fiber was calculated and used to generate anisometry profiles for the AL and PM bundles and HL at flexion angles of 0°, 30°, 60°, 90°, and 120°. Previously validated computer navigation software was used to re-create three dimensional bundles to measure fiber obliquity in the sagittal, frontal, and axial planes.
Results:
HL length increased with knee flexion from 0 to 120°, and underwent similar length changes as the PCL bundles. In full extension and at 90°, the average length of the PM and AL bundles were not statistically different (p=0.13 and p=0.85 respectively). From 0 to 120°, the PM bundle was the most isometric, but the anisometry profile was statistically similar to the AL bundle and HL. In general, HL and the PM bundle had similar graphic trends in terms of fiber obliquity in all planes.
Conclusions:
Using computer navigation, we have demonstrated that HL has similar isometry profiles as the PM and AL bundles of the PCL, and "mirrored" the obliquity of the PM bundle in all planes throughout flexion to 120°.
Related Concept Videos
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
Generalized Hooke's Law
Bones of the Upper Limb: Humerus
Transformation of Plane Strain
Under plane strain conditions, typical for members where one dimension significantly exceeds the others, deformations and resultant strains are...
Deformations in a Symmetric Member in Bending
When the member is segmented into tiny cubic elements, it is observed that the primary stress...
Hooke's Law

