Portfolio

Upcoming Event

Grand Rounds Seminar
"The Surgeon Inventor: Collaborative Innovation"
Frank Papay, M.D.
Chair, Dermatology and Plastic Surgery Institute
Joint appt., Head and Neck Institute
August 4, 2017

Role of the Native Fiber Bundles of the Anterior Cruciate Ligament in Knee Joint Kinematics

Client: Joe Carney M.D. / US Navy

Services Provided: Experiment Design / Robotic Knee Joint Testing / Data Analysis / Manuscript Preparation

Anatomical descriptions of the Anterior Cruciate Ligament (ACL) typically describe two distinct fiber bundles, the anterior-medial bundle (AMB) and the posterior-lateral bundle (PLB). This has inspired the development of double-bundle (DB), four-tunnel, reconstruction techniques for ACL ruptures. There are, however, no clinical studies yet that show an advantage of one technique over the other. Recent biomechanical studies have shown that the DB technique has the potential to reduce knee joint laxity, but it is not yet clear to what extent this is desirable or replicates the function of the native ACL bundles. The aim of this study was to determine the role of the native AMB and PLB via robotic testing in a cadaver model with and without weightbearing. Our results show that the AMB has a larger effect on anterior tibia translation than the PLB. Both bundles, however, appear to contribute equally to rotational stability at 15 degrees flexion or more. The PLB tended to have a larger contribution to rotational stability but only at full extension. It is premature to interpret these results with respect to the debate on single vs. double bundle reconstruction, but our results suggest that a single bundle reconstruction, placed at the AMB insertions, may be sufficient to restore translational stability. It should be kept in mind that these results were obtained without compressive load on the joint. Preliminary results suggest the ACL bundles have less influence on passive knee joint motion when Lachman and pivot shift tests are performed during simulated weightbearing.