The anterior cruciate ligament (ACL) is a major ligament of the knee. It is located in the center of the knee, and runs from the femur to the shin by way of the knee. It is the key stabilizer of this joint, and is essential to movement and a change of direction when ambulating or running. It is common to see this ligament damaged in football and baseball players. The ligament can be torn to various degrees or even completely "blown". The most common injury associated with the tearing of the ACL, has to do with a sudden directional change, or when a force of deceleration occurs in the knee, especially after rapid acceleration. The injured person will often recall a "popping" sound and/or sensation, along with almost immediate swelling, pain, and tenderness upon movement. It is also common for the patient to complain of his/her knee "giving out" when attempting to change direction. Initial treatment should include ice, anti-inflammatory medications, and rest. After the initial rest period, physical therapy may be used to restore range of motion and reduce pain in the knee.
The diagnosis of an ACL tear is usually arrived at by determining the mechanism of injury, trajectory/force of the injury, specialized examination the knee, determining the presence or absence of fluid/blood in the joint space, and diagnostic studies (x-rays and MRI scans seems to be the most common). A stress test of the ligament is often procured, as well. Still, the extent of the injury may not be fully visualized and therefore understood, until an arthroscopic examination is completed (sometimes is not even necessary to establish a diagnosis).
The initial treatment of an acute ACL injury often includes ice, anti-inflammatory medication, and physical therapy which is directed at restoring the range of motion to the injured knee joint and adjacent ligaments. When non-invasive methods are deemed ineffectual, a more evasive technique may be decided upon. There are many different repair options, including a simple repair or a full or partial reconstruction. Sometimes the tear is derided, or "cleaned up" and the area of the tear is repaired where the detachment occurred. Other times, if there is extensive damage, a reconstruction of the ligament is actually undertaken. Although a number of different types of tissue have been utilized to reconstruct the ACL, the most common type of ACL reconstruction involves harvesting the central third of the patellar tendon with a bone block at each end of the tendon graft, seems to work the best. This surgery takes place after a diagnostic arthroscopic examination of the knee, where the physician has the ability to harvest the central third of the patellar tend. Next, the remaining injured tendon is repaired. Drill guides are used to create holes into the tibia (shin bone), and femur (upper large leg bone above the knee), at the attachment sites of the original ACL ligament. When the graft is pulled through the new holes, the natural/original ligament is supported. After pulling the graft through the drill holes and into the joint to replace the torn ACL, the graft is then held in place with bio-absorbable screws or possibly metallic screws and other hardware.
The surgery requires extensive rehabilitation through PT, and sometimes other forms of alternative medicine, such as massage. Pain management can also be a concern, as the medications most often used for initial pain management are addictive (opiate analgesics), and the non-steroidal anti-inflammatory can also cause a myriad of problems, such as stomach ulcers, gastrointestinal bleeding, and even renal issues, in some patients. Still many patients respond well to this surgery and rehabilitation, and it has saved the career of many professional athletes.