ACL Reconstruction

Ligament Injuries to the Knee

What are knee ligaments?

There are four major ligaments in the knee. Ligaments are elastic bands of tissue that connect bones to each other and provide stability and strength to the joint. The four main ligaments in the knee connect the femur (thighbone) to the tibia (shin bone), and include the following:

• Anterior cruciate ligament (ACL). The ligament, located in the center of the knee, that controls rotation and forward movement of the tibia (shin bone).

• Posterior cruciate ligament (PCL). The ligament, located in the back of the knee, that controls backward movement of the tibia (shin bone).

• Medial collateral ligament (MCL). The ligament that gives stability to the inner knee.

• Lateral collateral ligament (LCL). The ligament that gives stability to the outer knee.

How are cruciate ligaments injured?

The anterior cruciate ligament (ACL) is one of the most common ligaments to be injured. The ACL is often stretched and/or torn during a sudden twisting motion (when the feet stay planted one way, but the knees turn the other way). Skiing, basketball, and football are sports that have a higher risk of ACL injuries.

The posterior cruciate ligament (PCL) is also a common ligament to become injured in the knee. However, the PCL injury usually occurs with sudden, direct impact, such as in a car accident or during a football tackle.

What are the symptoms of a cruciate ligament injury?

Often, a cruciate ligament injury does not cause pain. Instead, the person may hear a popping sound as the injury occurs, followed by the leg buckling when trying to stand on it, and swelling. However, each individual may experience symptoms differently.

The symptoms of a cruciate ligament injury may resemble other conditions or medical problems. Always consult your doctor for a diagnosis.

How are collateral ligaments injured?

The medial collateral ligament is injured more often than the lateral collateral ligament. Stretch and tear injuries to the collateral ligaments are usually caused by a blow to the outer side of the knee, such as when playing hockey or football.

What are the symptoms of a collateral ligament injury?

Similar to cruciate ligament injuries, an injury to the collateral ligament causes the knee to pop and buckle, causing pain and swelling.

The symptoms of a collateral ligament injury may resemble other conditions or medical problems. Always consult your doctor for a diagnosis.

How is a knee ligament injury diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for a knee ligament injury may include the following:

• X-ray. A diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

• Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body; can often determine damage or disease in a surrounding ligament or muscle..

• Arthroscopy. A minimally-invasive diagnostic and treatment procedure used for conditions of a joint. This procedure uses a small, lighted, optic tube (arthroscope) which is inserted into the joint through a small incision in the joint. Images of the inside of the joint are projected onto a screen; used to evaluate any degenerative and/or arthritic changes in the joint; to detect bone diseases and tumors; to determine the cause of bone pain and inflammation.

Treatment for knee ligament injuries

Specific treatment for a knee ligament injury will be determined by your doctor based on:

• Your age, overall health, and medical history

• Extent of the injury

• Your tolerance for specific medications, procedures, and therapies

• Expectation for the course of the injury

• Your opinion or preference

Treatment may include:

• Medication such as ibuprofen

• Muscle-strengthening exercises

• Protective knee brace (for use during exercise)

• Ice pack application (to reduce swelling)

• Surgery

Knee Ligament Repair

(ACL Repair, ACL Reconstruction, PCL Repair, PCL Reconstruction, MCL Repair, MCL Reconstruction, LCL Repair, LCL Reconstruction)

Procedure overview

What is knee ligament repair?

Ligaments are bands of tough, elastic connective tissue that surround a joint to give support and limit the joint's movement. When ligaments are damaged, the knee joint may become unstable. The ligament damage often occurs from a sports injury. A torn ligament severely limits knee movement, resulting in a person’s inability to pivot, turn, or twist their leg. Those individuals who cannot return to normal activities with medical treatments for a torn ligament may have the ligament repaired with surgery.

Anatomy of the knee

Joints are formed where bones meet. Most joints are mobile, allowing the bones to move. Basically, the knee is two long leg bones held together by muscles, ligaments, and tendons. Each bone end is covered with a layer of cartilage that absorbs shock and protects the knee.

There are two groups of muscles involved in the knee, including the quadriceps muscles (located on the front of the thighs), which straighten the legs, and the hamstring muscles (located on the back of the thighs), which bend the leg at the knee.

Tendons are tough cords of tissue that connect muscles to bones. Ligaments are elastic bands of tissue that connect bone to bone. Some ligaments of the knee provide stability and protection of the joints, while other ligaments limit forward and backward movement of the tibia (shin bone).

The knee consists of the following:

• Tibia. This is the shin bone or larger bone of the lower leg.

• Femur. This is the thighbone or upper leg bone.

• Patella. This is the kneecap.

• Cartilage. A type of tissue that covers the surface of a bone at a joint. Cartilage helps reduce the friction of movement within a joint.

• Synovial membrane. A tissue that lines the joint and seals it into a joint capsule. The synovial membrane secretes synovial fluid (a clear, sticky fluid) around the joint to lubricate it.

• Ligament. A type of tough, elastic connective tissue that surrounds the joint to give support and limits the joint's movement.

• Tendon. A type of tough connective tissue that connects muscles to bones and helps to control movement of the joint.

• Meniscus. A curved part of cartilage in the knees and other joints that acts as a shock absorber.

What are the ligaments of the knee?

There are four major ligaments in the knee. The ligaments in the knee connect the femur (thighbone) to the tibia (shin bone), and include the following:

• Anterior cruciate ligament (ACL). The ligament, located in the center of the knee, that controls rotation and forward movement of the tibia (shin bone).

• Posterior cruciate ligament (PCL). The ligament, located in the center of the knee, that controls backward movement of the tibia (shin bone).

• Medial collateral ligament (MCL). The ligament that gives stability to the inner knee.

• Lateral collateral ligament (LCL). The ligament that gives stability to the outer knee.

Reasons for the procedure

The anterior cruciate ligament (ACL) is located toward the front of the knee. It is the most common ligament to be injured. The ACL is often stretched and/or torn during a sudden twisting motion (when the feet stay planted one way, but the knees turn the other way). Skiing, basketball, and football are sports that have a higher risk of ACL injuries.

The posterior cruciate ligament (PCL) is located toward the back of the knee. It is also a common knee ligament to be injured. However, the PCL injury usually occurs with sudden, direct impact, such as in a car accident or during a football tackle.

The medial collateral ligament (MCL) is located on the inner side of the knee. It is injured more often than the lateral collateral ligament (LCL), which is on the outer side of the knee. Stretch and tear injuries to the collateral ligaments are usually caused by a blow to the outer side of the knee, such as when playing hockey or football.

Early medical treatment for knee ligament injury may include, but is not limited to, the following:

• Rest

• Ice pack application (to reduce swelling that occurs within hours of the injury)

• Compression (from an elastic bandage or brace)

• Elevation

• Pain relievers

A knee ligament tear may be treated with the following:

• Muscle-strengthening exercises

• Protective knee brace (for use during exercise)

• Activity limitations

Knee ligament repair is a treatment for a complete tear of a knee ligament that results in instability in the knee. Persons with a torn knee ligament may be unable to do normal activities that involve twisting or turning at the knee. The knee may buckle or “give-way.” If medical treatments are not satisfactory, ligament repair surgery may be an effective treatment.

The surgery to correct a torn knee ligament involves replacing the ligament with a piece of healthy tendon. A tendon from the kneecap or hamstring, for example, is grafted into place to hold the knee joint together. The tendon graft may come from the person (autograft) or from an organ donor (allograft).

There may be other reasons for you doctor to recommend a knee ligament repair.

Risks of the procedure

As with any surgical procedure, complications can occur. Some possible complications may include, but are not limited to, the following:

• Bleeding

• Infection

• Blood clots in the legs or lungs

Some individuals experience pain, limited range of motion in the knee joint, and occasional swelling in the knee after surgical ligament repair. Others have increased motion in the knee joint as the graft stretches over time.

There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.

Before the procedure

• Your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.

• You will be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear.

• In addition to a complete medical history, your doctor may perform a complete physical examination to ensure you are in good health before undergoing the procedure. You may undergo blood tests or other diagnostic tests.

• Notify your doctor if you are sensitive to or are allergic to any medications, latex, tape, and anesthetic agents (local and general).

• Notify your doctor of all medications (prescribed and over-the-counter) and herbal supplements that you are taking.

• Notify your doctor if you have a history of bleeding disorders or if you are taking any anticoagulant (blood-thinning) medications, aspirin, or other medications that affect blood clotting. It may be necessary for you to stop these medications prior to the procedure.

• If you are pregnant or suspect that you are pregnant, you should notify your doctor.

• You will be asked to fast for eight hours before the procedure, generally after midnight.

• You may receive a sedative prior to the procedure to help you relax. Because the sedative may make you drowsy, you will need to arrange for some to drive you home.

• You may meet with a physical therapist prior to your surgery to discuss rehabilitation.

• Arrange for someone to help around the house for a week or two after you are discharged from the hospital.

• Based on your medical condition, your doctor may request other specific preparation.

During the procedure

Knee ligament repair may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor’s practices.

Knee ligament repair may be performed while you are asleep under general anesthesia, or while you are awake under spinal anesthesia. If spinal anesthesia is used, you will have no feeling from your waist down. Your doctor will discuss this with you in advance.

Generally, knee ligament repair surgery follows this process:

1. You will be asked to remove clothing and will be given a gown to wear.

2. An intravenous (IV) line may be started in your arm or hand.

3. You will be positioned on the operating table.

4. The anesthesiologist will continuously monitor your heart rate, blood pressure, breathing, and blood oxygen level during the surgery.

5. The skin over the surgical site will be cleansed with an antiseptic solution.

6. The doctor will make several small incisions in the knee area.

7. The doctor will perform the surgery using an arthroscope (a small tube-shaped instrument that is inserted into a joint). The doctor may reattach the torn ligament or reconstruct the torn ligament by using a portion (graft) of the patellar tendon (that connects the kneecap to the tibia), the hamstring tendon (from the back of the thigh), or other autografts. The tendon graft may come from the person (autograft) or from an organ donor (allograft).

8. The doctor will drill small holes in the tibia and femur where the torn ligament was attached.

9. The doctor will thread the graft through the holes and attach it with surgical staples or screws. Bone eventually grows around the graft.

10. The incision will be closed with stitches or surgical staples.

11. A sterile bandage or dressing will be applied.

After the procedure

After the surgery you will be taken to the recovery room for observation. Your recovery process will vary depending on the type of anesthesia that is given. Once your blood pressure, pulse, and breathing are stable and you are alert, you will be taken to your hospital room or discharged to your home. Knee ligament repair is usually done on an outpatient basis.

You may be given crutches and a knee immobilizer before you go home.

Once you are home, it is important to keep the surgical area clean and dry. Your doctor will give you specific bathing instructions. The stitches or surgical staples will be removed during a follow-up office visit.

Take a pain reliever for soreness as recommended by your doctor. Aspirin or certain other pain medications may increase the chance of bleeding. Be sure to take only recommended medications.

To help reduce swelling, you may be asked to elevate your leg and apply an ice bag to the knee several times per day for the first few days. Your doctor will arrange for an exercise program to help you regain muscle strength, stability, and range of motion.

Notify your doctor to report any of the following:

• Fever

• Redness, swelling, bleeding, or other drainage from the incision site

• Increased pain around the incision site

You may resume your normal diet unless your doctor advises you differently.

Because of the limited mobility, it may be difficult for a few weeks to resume your normal daily activities. You may need someone at home to assist you. You should not drive until your doctor tells you to. Other activity restrictions may apply. Full recovery from the surgery and rehabilitation may take several months.

Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.

Online resources

The content provided here is for informational purposes only, and was not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your doctor. Please consult your health care provider with any questions or concerns you may have regarding your condition.

This page contains links to other websites with information about this procedure and related health conditions. We hope you find these sites helpful, but please remember we do not control or endorse the information presented on these websites, nor do these sites endorse the information contained here.

American Academy of Orthopaedic Surgeons

American College of Rheumatology

Arthritis Foundation

National Institute of Child Health and Human Development

National Institutes of Health (NIH)

National Library of Medicine

Tips for Preventing an ACL Knee Ligament Injury

The knee is a joint where three main bones join: the femur, or thigh bone; the tibia, or shin bone; and the patella, or knee cap. Several ligaments attach to the femur and tibia and give the joint strength and stability. One of these, the anterior cruciate ligament (ACL), is in the center of the knee and limits rotation and the forward movement of the tibia. Recent studies estimate that nearly 250,000 ACL injuries occur annually in the United States.

The ACL is most often stretched or torn by a sudden twisting motion--when, for example, your feet are planted one way and your knees are turned another. You can also injure your ACL by quickly changing the direction in which you're moving; by putting the brakes on too quickly when running; or, when landing from a jump. A woman's body structure and hormones cause more force on the ligaments, increasing the likelihood of injury during sports and athletic activities.

Recognizing an ACL injury

People who play basketball, volleyball, soccer, or football, or who ski are most likely to injure their ACLs when they slow down, pivot or land after a jump.

If you injure yours, you may not feel any pain immediately. You might hear a popping noise and feel your knee give out from under you.

Within a few hours, you'll notice swelling at the knee. The knee will often hurt when you try to stand on it. It's important to keep weight off the knee until you can see your health care provider, or you may injure the knee cartilage. You should use an ice pack to reduce swelling and keep the leg elevated. If needed, use a pain reliever. If you must walk, use crutches and be sure to see a doctor right away to have your knee evaluated.

Diagnosis

Your doctor may conduct physical tests and take X-rays and obtain an MRI to determine the extent of your ACL damage. If the ACL is only partially torn, your doctor may prescribe an exercise program to strengthen surrounding muscles and a brace to protect the knee during activity. You may or may not need surgery. Surgery can be performed to reconstruct the torn ligament from a piece (graft) of strong, healthy tissue taken from another area near the knee (autograft) or from a cadaver (allograft). If the ACL is completely torn, it may need to be replaced surgically.

Successful surgery tightens your knee and restores its stability, which helps you avoid further injury.

After ACL reconstruction, you'll need to do rehabilitation exercises to gradually return your knee to full flexibility and stability.

You also may need a knee brace temporarily and will probably have to stay out of sports for about six months to a year after the surgery.

Prevention

Many ACL injuries can be prevented if the muscles that surround the knees are strong and flexible.

Prevention focuses on proper nerve and muscle control of the knee. Exercises aim to increase muscle power, balance, and improve core strength and stability.

The following training tips can reduce the risk of an ACL injury:

• Train and condition year round.

• Practice proper landing technique after jumps.

• When you pivot, crouch and bend at the knees and hips. This reduces stress on the ACL.

• Strengthen your hamstring and quadriceps muscles. The hamstring muscle is at the back of the thigh; the quadriceps muscle is at the front. The muscles work together to bend or straighten the leg. Strengthening both muscles can better protect the leg against knee injuries.