The surgery to repair a torn anterior cruciate ligament or ACL is usually done as a day surgery.
The surgeon makes a small incision in the knee to be able to see and access the torn ligament. This is usually done with an arthroscope, a small instrument with a camera on one end. Through other small incisions, the surgeon can use instruments to do the repair. Using these instruments, the surgeon removes the old ligament and drills a hole (tunnel) to fasten down the new ligament.
The new ligament may be taken from the patient him or herself from a tendon. This is then fastened into place where the old legament was.