Beware of a Meniscus Tear if you have no ACL!

Is surgery for a knee meniscus tear with no ACL a good idea?  We’ve seen many patients walking around without a knee ACL ligament as a result of an old complete rupture of that ligament. Recently, more and more research has been showing that many patients do well without an ACL ligament and that replacing the ligament might not be helpful. Since the ACL knee ligament provides stability to the knee in a front-back direction, patients with torn ACL ligaments tend to develop a knee joint where the femur bone fits into the tibia a bit like a shallow ball and socket joint. This new joint configuration allows the knee to be more stable. However, before those long term changes occur, there may be situations were not having an ACL can be more risky. For example, a recent study demonstrated that in a knee without an ACL. a tear in the posterior medial meniscus causes more instability of the knee. Our practice’s e-book, Orthopedics 2.0 talks about the importance of joint stability for warding off arthritis. In this case, the ACL ligament deficient knee uses the meniscus to provide more stability. Since the ACL would normally prevent the tibia bone from sliding forward on the femur, a knee without an ACL uses the meniscus to perform the same function. So if the meniscus begins to fail in a knee without an ACL ligament, the knee will become more unstable. The upshot? If you have a knee with no ACL ligament , be wary of tears in the meniscus. This also likely means that traditional knee surgeries that remove parts of the torn meniscus will also make the knee less stable. As a result, you may want to consider newer biologic therapies for your knee meniscus tear like injections of your own stem cells.