The ACL, also known as the anterior cruciate ligament, is a band of connective tissue that runs diagonally through the middle of the knee. This ligament keeps the tibia from moving in front of the femur when the knee is moving. A torn ACL can cause the knee to be unstable and give out easily and often requires surgical reconstruction of the ligament.
Diagnosis
Surgery may be required on the ACL if the ligament has been torn. The diagnosis of a torn ACL, the Mayo Clinic explains, often begins with the physician asking for details about the knee injury, particularly if a "pop" was heard or felt at the time of the injury. Two different tests as part of a physical exam, known as the Lachman's test and pivot shift test, can also be used to diagnose an ACL tear. Finally, an MRI can be used to definitively diagnose a torn ACL and also determine if any other structures in the knee are injured.
Graft Options
A torn ACL is generally not sewn back together, according to the American Academy of Orthopedic Surgeons, because this type of repair typically fails. Instead, the ACL is replaced with a graft taken from a tendon. The graft can be taken from the patient's quadriceps, patellar or hamstring tendons. Another option is to use a tendon from a cadaver to reconstruct the ACL.
Surgical Proceduree
ACL knee surgery is usually done under general anesthesia, the American Academy of Orthopedic Surgeons explains. Once the graft has been prepared, the orthopedic surgeon will make several small incisions that allow for the use of a special camera called an arthroscope and specialized tools. Arthroscopic surgery allows the ACL to be replaced without using a large incision. Typically small tunnels are drilled into the femur and tibia so that the graft can be positioned to very close to the original ligament's location. The graft is then put into place and anchored using using surgical staples or screws, and the original incisions are stitched shut.
Post-Operative Care
Most patients are able to go home the day after the surgery, the National Institutes of Health explains. For the first several weeks, patients may need to wear a knee brace and use crutches most of the time to help stabilize and protect the knee as the surgical site heals. Physical therapy helps patients regain range of motion and strength in the knee joint. Full recovery from ACL surgery typically takes between four and six months.
Risks
Patients undergoing ACL knee surgery run the risk of bleeding or infections as a result of the surgery. Some patients can develop breathing problems or have an allergic reaction while under anesthesia. With the surgery there is also the risk that the surgical repair will not work or that the patient's knee will still be damaged after the surgery. The knee may still be stiff, limited in its range of motion, or be painful. These risks should all be considered before a patient has surgical treatment for a torn ACL.
