Dr. Johnson describes the bundles of ligaments that make up the anterior cruciate ligament (ACL).
The anterior cruciate ligament is composed of two bundles–the anterolateral and the posteromedial bundle. It’s not really, when you look at it structurally, it’s not like you look at it, and there’s two separate bundles. It’s actually one ligament, but we use the term two functional bundles, and what do we mean by that?
Well, we mean that as you flex and extend your knee, different portions of the ACL are the most important. For example, in flexion, so sitting here on this chair with my knee flexed 90 degrees, your posterolateral bundle is not doing too much. It’s a little bit loose. It really serves as a check rein.
Now when I straighten my knee, that posterolateral bundle gets important to help with rotation. So if you look at the ACL, you are not going to look in somebody’s knee and go, wow, there’s two ligaments there. It’s one ligament made up of two functional bundles, is the term we use.
About Dr. Johnson, M.D.:
Dr. Darren L. Johnson, M.D., received his medical degree from the University of California, Los Angeles School of Medicine. He completed his residency at the University of Southern California School of Medicine, Los Angeles and his fellowship at the University of Pittsburgh Medical Center.
Dr. Johnson is currently Professor and Chairman of Orthopaedic Surgery and Director of Sports Medicine at the University of Kentucky. His clinical interests include arthroscopy, knee and shoulder reconstruction and the double-bundle procedure for ACL repair.
Dr. Johnson was named among the Top Doctors for Women by Women’s Health magazine in 2008.