Ligaments are strong bands of tissue that connect one bone to another. The anterior cruciate ligament (ACL) is one of four major ligaments in the knee. It is in the center of the knee joint, connecting the thigh bone (femur) to the shin bone (tibia). The ACL helps keep the knee stable by limiting twisting and forward sliding motions of the knee.
The ACL is commonly injured in sports when there is a forced twisting motion of the knee or when the knee is hit while the foot is planted. It may also be injured during a sudden stop when the femur moves forcefully over the tibia.
A torn ACL will not heal by itself. In the past, healthcare providers tried to repair the ACL by sewing the torn ends of the ligament together, but this did not work. The ACL must be reconstructed by using ligaments or tendons from another part of the body to replace the torn ACL. Tendons are connective tissue bands that attach muscles to bones. The replacement tissue is called a graft.
The grafts can come from several places. Most often the graft is taken from the patellar tendon, which attaches your kneecap (patella) to your shin bone (tibia). The graft is made up of the middle third of the patellar tendon and small pieces of bone from the kneecap and the shin bone. A graft may also come from your hamstring tendon. The hamstring muscles are in the back of your thigh.
If the graft comes from your own body, it is called an autograft. If the graft comes from someone who has died, it is called an allograft. Providers have tried using some types of synthetic grafts but so far these have not worked well. Research is being done to see if there are better types of grafts that can be used.
Your healthcare provider will discuss the options with you and will help you decide which procedure is best for you.
You may consider having reconstructive ACL surgery if:
You may consider not having the surgery if:
If a growing child tears an ACL, the healthcare provider may recommend that surgery be postponed until the child has stopped growing.
Plan for your care and recovery after surgery. Allow time to rest, and try to find people to help you for a few days.
Follow your healthcare provider's instructions. You may be asked not to take aspirin for a week or so before your surgery. Do not eat or drink anything after midnight or the morning before surgery. You may have physical therapy before surgery to begin your rehabilitation.
You will have either general or spinal anesthesia. A general anesthetic will relax your muscles and make you feel as if you are in a deep sleep. A spinal anesthetic leaves you awake but unable to feel anything from the waist down.
Your healthcare provider will prepare the graft. If your patellar tendon is to be used, the provider will make an incision 1 to 3 inches below your kneecap. Then he or she will remove your torn ACL using an arthroscope. An arthroscope is a thin tube through which your provider can view the inside of your knee joint. Various thin, small instruments are used to perform surgery in the knee. Your provider will drill holes in your femur and tibia where the graft will be attached. The graft will be passed through the holes and anchored in place by screws or staples. The incisions from the graft site and the arthroscopy will be closed with stitches, tape, or staples.
During your surgery, your provider may also treat any other knee injuries such as torn cartilage.
You may be allowed to go home a few hours after surgery or you may have to spend the night in the hospital. Treatment after surgery may include:
You may be on crutches for a week or two after surgery. You may not be able to drive for at least a few weeks.
Complications may include:
Everyone recovers from an injury at a different rate. Return to your activity depends on how soon your knee recovers, not by how many days or weeks it has been since your injury has occurred. In general, the longer you have symptoms before you start treatment, the longer it will take to get better. The goal of rehabilitation is to return you to your normal activities as soon as is safely possible. If you return too soon you may worsen your injury.
Rehabilitation from ACL surgery is very complex. Your healthcare provider and therapist will watch your progress very carefully and gradually allow you to be more active. It may take 4 to 9 months of rehabilitation to get back to some activities. It may take 12 months or more for your knee to feel the way it did before your injury.
Call your healthcare provider immediately if:
Call your healthcare provider during office hours if: