Surgery for anterior cruciate ligament (ACL) injuries involves reconstructing or repairing the ACL.
ACL surgery is done by making small incisions in the knee and inserting instruments for surgery through these incisions (arthroscopic surgery) or by cutting a large incision in the knee (open surgery).
ACL surgeries are done by orthopedic surgeons.
Many orthopedic surgeons use arthroscopic surgery rather than open surgery for ACL injuries because:
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.
The surgeon will make another incision in the knee and take the graft (replacement tissue) at this point. If it comes from the tendon at the front of the knee, it will include two small pieces of bone called "bone blocks" on the ends of the tissue. One piece of bone is taken from the kneecap and the other piece is taken from a part of the lower leg bone near the knee joint. If the autograft comes from the hamstring, bone blocks are not taken. The graft may also be taken from a deceased donor (allograft).
See a picture of a bone and tissue graft.
The graft is pulled through the two 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.
Arthroscopic surgery is often done on an outpatient basis, which means that you do not spend a night in the hospital. Other surgery may require staying in the hospital for a couple of days.
To care for your incision while it heals, you need to keep it clean and dry and watch for signs of infection.
Physical rehabilitation after ACL surgery may take several months to a year. The length of time until you can return to normal activities or sports is different for every person. It may range from 4 to 6 months.3
The goal of ACL surgery is to restore normal or almost normal stability in the knee and the level of function you had before the knee injury, limit loss of function in the knee, and prevent injury or degeneration to other knee structures.
Not all ACL tears require surgery. You and your doctor will decide whether rehabilitation (rehab) only or surgery plus rehab is right for you.
You may choose to have surgery if you:
You may choose not to have surgery if you:
For more information, see the topic:
After an ACL injury and surgery, the knee is never "normal." But most people regain enough strength and range of motion to return to their usual activities. ACL repair is usually successful for an ACL that has torn away from the upper or lower leg bone (avulsion).
A few people who have ACL surgery still have knee pain and instability and may need another surgery (revision ACL reconstruction). Revision ACL reconstruction is generally not as successful as the initial ACL reconstruction.
ACL reconstruction surgery is generally safe. Complications that may arise from surgery or during rehabilitation (rehab) and recovery include:
In an avulsion fracture, repair surgery is always done as soon as possible.
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.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).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 non-surgical treatments and may try to change their activity levels to protect their knees from further injury.
Current research on the surgical treatment of ACL injuries includes different techniques and places to attach grafts; different ways of securing the graft; different types of grafts, such as tendon, muscle, or fascial grafts from your body (autograft); and grafts from a donor (allograft). When choosing a graft, consider the following:
- Honkamp NJ, et al. (2010). Anterior cruciate ligament injuries in adults. In JC DeLee et al., eds., Delee and Drez's Orthopaedic Sports Medicine: Principles and Practice, 3rd ed., vol. 2, pp. 1644–1676. Philadelphia: Saunders Elsevier.
- Pinczewski LA, et al. (2007). A 10-year comparison of anterior cruciate ligament reconstructions with hamstring tendon and patellar tendon autograft: A controlled prospective trial. American Journal of Sports Medicine, 35(4): 564–574.
- McMahon PJ, Kaplan LD (2006). Anterior cruciate ligament injuries section of Sports medicine. In HB Skinner, ed., Current Diagnosis and Treatment in Orthopedics, 4th ed., pp. 180–183. New York: McGraw-Hill.
Last Revised: April 29, 2012
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