Surgery for anterior cruciate ligament (ACL) injuries involves reconstructing or repairing the ACL. ACL reconstruction surgery uses a graft to replace the ligament. The most common grafts are autografts using part of your own body, such as the tendon of the kneecap (patellar tendon) or one of the hamstring tendons. Another choice is allograft tissue, which is taken from a deceased donor. Repair surgery is used in the case of an avulsion fracture (a separation of the ligament and a piece of the bone from the rest of the bone). In this case, the bone fragment connected to the ACL is reattached to the bone. In ACL surgery, the surgeon makes small incisions in the knee and inserts instruments for surgery through these incisions (arthroscopic surgery) or by cutting a large incision in the knee (open surgery). The recovery after ACL repair may take several months up to a year, and requires physical rehabilitation. The length of time until the patient can return to normal activities or sports, is different for every person.