Tearing of the ACL usually occurs with a sudden direction change or when a deceleration force crosses the knee. The patient often feels or hears a popping sensation, has the rapid onset of swelling, and develops a buckling sensation in the knee when attempting to change direction.
The diagnosis of the ACL injury is usually arrived at by determining the mechanism of injury, examining the knee, determining the presence or absence of blood within the joint, and performing diagnostic studies. These may include x-rays, MRI scans and stress tests on the ligament.
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 of the injured knee.
Surgical treatment of the torn ACL usually involves an arthroscopic surgical reconstruction of the injured ligament.
After harvesting the tissue, drill guides are used to place holes into the tibia (bone below the knee) and femur (bone above the knee). By placing the drill holes at the attachment sites of the original ligament, when the graft is pulled through the drill hole and into the knee, it will be placed in the same position as the original ACL.
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 bioabsorbable screws or metallic screws.
ACL reconstruction can be done using an anatomically-placed single bundle or double bundle autograft or allograft. Fastening the graft in this manner allows new blood vessels to grow into the transferred graft and for healing to occur. Typically, the procedure is performed on an outpatient basis.
Post-operatively, it is possible to bear weight (partial weight bearing) on the surgically treated leg by using crutches for the first 7- 10 days after surgery. Patients may stop using crutches when comfortable. Supervised physical therapy often is started by the second to third day after surgery.
In addition, a continuous passive motion device is applied to the injured leg post-operatively. Most patients use this device while sleeping for the first two weeks. This device very slowly moves the knee, thereby decreasing the risk of stiffness and loss of motion. Following an initial 6- 10 week period of supervised physical therapy, most patients will progress to a self-directed program that is done in a health club. Typically, it takes the reconstructed ligament approximately 9 months to heal. Until given clearance by Dr. Yu, contact sports, racket sports, skiing, martial arts, and sports that require rapid direction changes must be avoided.