Surgery Overview

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. Sometimes the quadriceps tendon from above the kneecap is used. Another choice is allograft tissue, which is taken from a deceased donor.
• Repair surgery typically is used only 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.

ACL surgery is usually done by making small incisions in the knee and inserting instruments for surgery through these incisions (arthroscopic surgery). In some cases, it is done by cutting a large incision in the knee (open surgery).

ACL surgeries are done by orthopedic surgeons.

In reconstruction of a partial or complete tear of the ACL, the best time for surgery is not known. Surgery immediately after the injury has been associated with increased fibrous tissue leading to loss of motion (arthrofibrosis) after surgery.^{footnote 1} Some experts believe that surgery should be delayed until the swelling goes down, you have regained range of motion in your knee, and you can strongly contract (flex) the muscles in the front of your thigh (quadriceps).^{footnote 1} Many experts recommend starting exercises to increase range of motion and regain strength shortly after the injury.

In adults, age is not a factor in surgery, although your overall health may be. Surgery may not be the best treatment for people with medical conditions that make surgery a greater risk. These people may choose nonsurgical treatments and may try to change their activity levels to protect their knees from further injury.

Arthroscopic surgery

Many orthopedic surgeons use arthroscopic surgery rather than open surgery for ACL injuries because:

• It is easy to see and work on the knee structures.
• It uses smaller incisions than open surgery.
• It can be done at the same time as diagnostic arthroscopy (using arthroscopy to find out about the injury or damage to the knee).
• It may have fewer risks than open surgery.

Arthroscopic surgery is done under regional (such as spinal) anesthesia or general anesthesia.

What happens

During arthroscopic ACL reconstruction, the surgeon makes several small incisions—usually two or three—around the knee. Sterile saline (salt) solution is pumped into the knee through one incision to expand it and to wash blood from the area. This allows the doctor to see the knee structures more clearly.

The surgeon inserts an arthroscope into one of the other incisions. A camera at the end of the arthroscope transmits pictures from inside the knee to a TV monitor in the operating room.

Surgical drills are inserted through other small incisions. The surgeon drills small holes into the upper and lower leg bones where these bones come close together at the knee joint. The holes form tunnels through which the graft will be anchored.

If you are using your own tissue, the surgeon will make another incision in the knee and take the graft (replacement tissue).

The graft is pulled through the tunnels that were drilled in the upper and lower leg bones. The surgeon secures the graft with hardware such as screws or staples and will close the incisions with stitches or tape. The knee is bandaged, and you are taken to the recovery room for 2 to 3 hours.

During ACL surgery, the surgeon may repair other injured parts of the knee as well, such as menisci, other knee ligaments, cartilage, or broken bones.