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. The ligament may tear when you slow down suddenly to change direction or pivot with your foot firmly planted, twisting or overextending your knee.
But not everyone who tears an ACL requires ACL reconstruction. Sedentary people who forgo sports that involve a lot of quick stops and changes in direction usually recover well with conservative treatments and physical therapy.
Your doctor may recommend ACL reconstruction 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, such as stair climbing
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
Before your surgery, you may need several weeks of physical therapy to restore your knee's full range of motion. People who go into surgery with a stiff, swollen knee often have problems regaining full range of motion after surgery.
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 your surgery to reduce your risk of bleeding. Follow your doctor's instructions about when to stop eating the night before your 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.
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 the others to allow surgical instruments access to the joint space.
During the procedure
After removing the damaged ligament, your surgeon will replace it with a piece of tendon from another part of your leg or, possibly, from a deceased donor. Your surgeon will drill tunnels into your thighbone and shinbone to accurately position the graft, which is then secured to your bones with screws or other fixation devices.
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.
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. Use crutches to avoid 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.
Successful ACL reconstruction paired with rigorous rehabilitation can 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 side. Athletes often can return to their sports after six to 12 months.