Ligaments are rope like bands of tough, leathery tissue that stabilize our joints. They span across the joint like a bridge, anchored to one bone above the joint, and another bone below the joint. Their purpose is to allow the joint to move freely through its normal range of motion, but to resist motion in abnormal directions. There are four major ligaments in the knee: two collateral ligaments (medial and lateral) on the sides of the joint and two cruciate ligaments (anterior and posterior) in the center of the joint. These ligaments are thick, about the same diameter as your pinky finger, and they are very strong, but if you twist your knee hard enough, you can tear one or more of them.
The ligament can be completely torn or just partially torn, depending on the injury. After tearing a ligament, you are likely to experience pain, stiffness, swelling and weakness in your knee. These symptoms are likely to subside with time, but you may notice a sense of instability or “wobbliness” once you feel good enough to start walking around again. Tears of the medial collateral (MCL) and lateral collateral (LCL) ligaments usually heal without surgery. Your doctor may recommend a brace to stabilize your knee while the ligament heals, and you may have to avoid certain activities until the ligament is healed and your knee muscle strength has returned. Tears of the anterior cruciate (ACL) and posterior cruciate (PCL) ligaments don’t heal well on their own. If you are an active person who enjoys sports or has a physically demanding job, an ACL tear will likely require surgical reconstruction using either a cadaver (organ donor) graft or a graft from another part of your own knee (hamstrings and patellar tendon tissues are often used). These grafts are used to replace the torn ligament since sewing the “stumps” of the torn ligament back together does not work. The graft is attached to the patient’s bone using a variety of fixation devices, such as screws or pin, depending on your surgeon’s preference. While ACL reconstruction is generally considered major surgery, the operation has an excellent track record for getting college, recreational and professional athletes back to the sports and activities they enjoy. Most patients are on crutches for one to two weeks, and are in physical therapy for one to two months. ACL reconstruction patients typically don’t return to high demand sports until six to nine months after surgery. The treatment of PCL tears is more complicated, and specific recommendations vary depending on the details of the injury and the individual patient.