Reconstruction of the anterior cruciate ligament (ACL) is a
surgery designed to restore knee stability and strength after the ligament has
been torn. The remnants of the torn ligament must be removed and replaced with
another ligament from your body or with tissue from a cadaver.
The knee is a hinge joint where the femur, or thighbone, meets the tibia, or shinbone. This important joint is held together by these
four ligaments, which connect
bones to one another:
- anterior cruciate ligament (ACL)
- medial collateral ligament (MCL)
- lateral collateral ligament (LCL)
- posterior cruciate ligament (PCL)
Your ACL runs diagonally between the femur and the tibia and
keeps the tibia from slipping in front of the femur. It also provides stability
to the knee when it rotates from side to side.
An ACL tear is one of the most common knee injuries, especially
among people who participate in high-impact sports like:
The majority of those
injuries occur without impact to another player, according to the American
Academy of Orthopaedic Surgeons (AAOS). They most often occur when an
athlete twists or pivots during play.
There are about 200,000 ACL injuries every year in the United
States, and according to the AAOS, about half of those injured undergo ACL
Why ACL Reconstruction Is Performed
ACL reconstructive surgery is done to repair a torn ACL and
regain stability and movement in the knee. While not all cases of a torn
ligament require surgery, very active people or those in persistent pain may
opt for surgery.
ACL reconstruction is often recommended if:
- you are young and active
- you suffer from persistent knee pain
- your injury causes your knee to buckle during
routine activities, such as walking
- you are an athlete who wants to remain active
How to Prepare for ACL Reconstruction
You will have appointments with your doctor and surgeon prior to
surgery. You’ll discuss treatment options, undergo several knee examinations,
and make a decision about which type of anesthesia to use during surgery.
During these meetings, it’s important to ask questions.
Discuss with your doctor where the surgically-implanted tendon will
come from. Typical sources for these tendons include:
tendon: the tendon that attaches the bottom of your kneecap, or patella, to your tibia
the tendon that connects the long muscles in the back of your leg to the back
of your knee
a tendon from the front of the thigh. This type of graft is typically reserved
for taller or heavier patients, or for people who have had previous
tissue from a dead body, which is called an allograft
While all cadavers are carefully screened for disease prior to
surgery, some people have concerns about using dead tissue. Discuss any
concerns you have with your doctor.
Your doctor will give you complete instructions for the day of
your surgery. Instructions may include fasting for 12 hours prior to surgery
and refraining from taking aspirin or blood-thinning medications.
Make sure to arrange to have someone come with you for surgery.
It’s helpful to have another person listen to post-operative instructions and
to drive you home.
How ACL Reconstruction Is Performed
You’ll be prepped for the surgery by changing into a hospital
gown and having an intravenous (IV) line placed in your arm. The IV will allow
the surgical team to administer medications, anesthesia, or sedatives.
Once the sample tissue is selected, it’s either surgically
removed from your body or prepared from a cadaver. The tendon is then outfitted
with “bone plugs,” or anchor points, to graft the tendon into the knee.
During surgery, a small incision is made in the front of the knee
for an arthroscope — a thin tube
outfitted with a fiber optic camera and surgical tools. This allows your
surgeon to see inside your knee during the procedure.
The surgeon will first remove your torn ACL and clean the area. They
will then drill small holes into your tibia and femur so the bone plugs can be
attached with posts, screws, staples, or washers.
Following the attachment of the new ligament, the surgeon will
test your knee’s range of motion and tension to ensure the graft is secure. Finally,
the opening will be stitched, the wound dressed, and your knee will be stabilized
with a brace. The length of the surgery will vary depending on the experience
of the surgeon and if additional procedures are performed (such as, meniscal
repair), among other factors.
Typically, you can go home the day of your surgery.
The Risks of ACL Reconstruction
Because ACL reconstruction is a surgical procedure, it carries
certain risks, including:
- bleeding and blood clots
- continued knee pain
- disease transmission if the graft comes from a
- knee stiffness or weakness
- loss of range of motion
- improper healing if the graft is rejected by
your immune system
Young children with ACL tears run the risk of growth plate
injuries. Growth plates allow bones to grow and are located at the ends of
bones in the arms and legs. Growth plate injuries can result in shortened bones.
Your doctor will evaluate these risks when deciding if surgery
should wait until your child is older and their growth plates have formed into
ACL reconstructive surgery remains the gold standard for
repairing this common knee injury. The AAOS reports that about 82 to 90 percent of
ACL reconstruction surgeries yield excellent results and full knee stability.
After ACL Reconstruction
Rehabilitation is key to the success of ACL reconstruction.
Immediately after surgery, you’ll be advised to take pain
medications, keep your incision clean and dry, and rest. Icing your knee is
extremely important as it helps alleviate pain and decreases swelling. You’ll
most likely have a follow-up appointment with your doctor or surgeon within a
few weeks of surgery.
Here’s what to expect following ACL surgery:
- some pain
- restricted activity for several months
- walking with crutches for up to six weeks
- wearing a knee brace for at least one week
You can expect to regain range of motion in your knee within a
few weeks after surgery. Athletes typically return to their sports within six
to 12 months.
Once the surgery has been deemed successful, a physical therapy
regimen can begin. The success of such therapy varies from person to person.