Medically reviewed on March 21, 2018
ACL reconstruction is surgery to replace a torn anterior cruciate (KROO-she-ate) ligament (ACL) — one of the major ligaments in your knee. ACL injuries most commonly occur during sports that involve sudden stops and changes in direction — such as basketball, soccer, football, tennis, downhill skiing, volleyball and gymnastics.
In an ACL reconstruction, the torn ligament is removed and replaced with a piece of tendon from another part of your knee or from a deceased donor. This surgery is an outpatient procedure that's performed through small incisions around your knee joint.
An ACL reconstruction is performed by a doctor who specializes in surgical procedures of the bones and joints (orthopedic surgeon).
Why it's done
Ligaments are strong bands of tissue that connect one bone to another. The ACL, one of two ligaments that cross in the middle of the knee, connects your thighbone (femur) to your shinbone (tibia) and helps stabilize your knee joint.
Most ACL injuries happen during sports and fitness activities that can put stress on the knee:
- Suddenly slowing down and changing direction (cutting)
- Pivoting with your foot firmly planted
- Landing from a jump incorrectly
- Stopping suddenly
- Receiving a direct blow to the knee
A course of physical therapy may successfully treat an ACL injury for individuals who are relatively inactive, engage in moderate exercise and recreational activities, or play sports that put less stress on the knees.
ACL reconstruction is generally recommended if:
- You're an athlete and want to continue in your sport, especially if the sport involves jumping, cutting or pivoting
- More than one ligament or the cartilage in your knee is injured
- You're young and active
- The injury is causing your knee to buckle during everyday activities
The anterior cruciate ligament (ACL) is one of the key ligaments that help stabilize your knee joint. The ACL connects your thighbone (femur) to your shinbone (tibia). It's most commonly torn during sports that involve sudden stops and changes in direction — such as basketball, soccer, tennis and volleyball.
ACL reconstruction is a surgical procedure. And, as with any surgery, bleeding and infection at the surgical site are potential risks. Other risks associated with ACL reconstruction include:
- Knee pain, stiffness or weakness
- Poor healing of the graft
- Failure to achieve symptom relief
How you prepare
Before your surgery, you will likely undergo several weeks of physical therapy. The goal before surgery is to reduce pain and swelling, restore your knee's full range of motion and strengthen muscles. People who go into surgery with a stiff, swollen knee often have poor healing and don't regain full range of motion after surgery.
ACL reconstruction is an outpatient procedure, so you'll be able to go home later that same day. Arrange for someone to drive you home.
Food and medications
Share with your surgeon a list of any medications, herbal medicines or dietary supplements you take regularly. If you regularly take aspirin or other blood-thinning medications, your doctor may ask you to stop taking these types of drugs for at least a week before surgery to reduce your risk of bleeding.
Follow your doctor's instructions about when to stop eating, drinking and taking any other medication the night before your surgery.
What you can expect
In most instances, general anesthesia is used during ACL reconstruction, so you'll be unconscious during the procedure. ACL reconstruction is usually done through small incisions — one to hold a thin, tube-like video camera (arthroscope) and others to allow surgical instruments access to the joint space.
During the procedure
In ACL reconstruction the surgeon removes the damaged ligament rather than repairing it. The damaged ligament is replaced with a segment of tendon, tissue similar to a ligament that connects muscle to bone. This replacement tissue is called a graft. Your surgeon will use a piece of tendon from another part of your knee or a tendon from a deceased donor.
Your surgeon will drill sockets or tunnels into your thighbone and shinbone to accurately position the graft, which is then secured to your bones with screws or other fixation devices. The graft will serve as scaffolding on which new ligament tissue can grow.
After the procedure
Once you recover from the anesthesia, you'll be allowed to go home later that same day. Before you go home, you'll practice walking with crutches, and your surgeon may ask you to wear a knee brace or splint to help protect the graft.
Before you leave the hospital, you will receive instructions on when you can shower or bathe, when you should change dressings on the wound, and how to manage post-surgery care. To reduce swelling and pain in the days immediately following your surgery, follow the R.I.C.E. model of self-care at home:
- Rest. General rest is necessary for recovery after surgery. Follow your surgeon's advice on how long to use crutches and limit weight-bearing on your knee.
- Ice. When you're awake, try to ice your knee at least every two hours for 20 minutes at a time.
- Compression. Wrap an elastic bandage or compression wrap around your knee.
- Elevation. Lie down with your knee propped up on pillows.
Progressive physical therapy after ACL surgery helps to strengthen the muscles around your knee and improve flexibility. A physical therapist will teach you how to do exercises that you will perform either with continued supervision or at home. Adhering to a rehabilitation plan is important for proper healing and achieving the best possible outcomes.
Successful ACL reconstruction paired with rigorous rehabilitation can usually restore the stability and function to your knee. Within the first few weeks after surgery, you should strive to regain knee range of motion equal to that of your opposite knee. Athletes often can return to their sports after eight to 12 months.