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ACL Injuries

ACL sprains and tears are the most common injuries to ligaments in your knee. Many people have issues with balance, buckling, or even the joint giving out.

ACL injuries can happen to anyone and can be a game-changer, especially for athletes. That's why many people with an ACL tear need surgery to get back to playing well.

At UPMC, we offer many treatment options for ACL injuries, ranging from non-surgical techniques to ACL reconstruction surgery. The type of treatment depends on how severe your ACL injury is.

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What Is an ACL Tear?

A torn ACL is a common injury to the anterior cruciate ligament in the knee. This type of injury can affect anyone.

The ACL is the main ligament that connects your shinbone (tibia) with the thighbone (femur).

Your knee joint has 3 bones:

  • Femur (thigh bone).
  • Tibia (shin bone).
  • Kneecap.

Four ligaments hold these bones in place. The ACL crosses the middle of the knee, forming an "X" shape and providing stability.

When the ACL tears, your knee can become unstable and may buckle or give way.

How common is an ACL injury?

ACL injuries account for almost half of all knee injuries. There are about 400,000 ACL reconstructions in the U.S. each year.

What are the types of ACL tears?

Doctors grade ACL tears using a grading system based on how severe an ACL tear is:

  • Grade 1 (least severe ACL injury). You stretched but didn't quite tear the ACL. The ligament can still keep the knee joint stable.
  • Grade 2 (partial tear). You stretched the ACL, making it loose. The ligament can't provide full stability to the joint.
  • Grade 3 (most severe ACL injury). A complete or near complete tear — the ligament has split into 2 pieces. Grade 3 is the most common type of ACL injury.

What causes an ACL injury?

Any motion that causes your knee joint to move outside its natural range of motion can lead to an ACL tear or injury. This type of injury occurs more often in activities with:

  • Stop/start motions.
  • Pivoting.
  • Rapid direction changes.

These types of movements can cause the knee joint to bend backward, twist, or bend to the side. The chance of injury is higher when more than 1 of these movements occur at the same time.

You can also sprain or tear your ACL by falling off a ladder or slipping on a staircase.

Like other body parts, the ACL tends to weaken with age. People over age 40 may be more susceptible to ACL tears.

What are ACL injury risk factors and complications? 

An ACL sprain or tear isn't limited to athletes, although many are at a higher risk because of the sport they play. An ACL injury can happen to anyone.

This type of injury can impact your day-to-day life and your ability to play sports. Due to the location of the ligament and its effect on the body, it's necessary to treat ACL injuries to preserve:

  • Activity levels.
  • Functioning.
  • The ability to walk without pain.

ACL tear risk factors 

ACL tears occur more often in athletes who play high-intensity sports, such as: 

  • Football.
  • Basketball.
  • Soccer. 

Sports like these involve quick, frequent movements like jumping, stopping, and changing direction, which can put you at higher risk for an ACL injury.

Female athletes are especially at risk for ACL tears. 

ACL tear complications 

Reinjury is the most common complication of an ACL tear. If you've already torn your ACL and you play sports regularly, you're more likely to injure it again.

If left untreated, ACL injuries may result in ongoing joint and mobility issues later in life. 

How can I prevent an ACL injury? 

There are things you can do to help lower the risk of an ACL tear or injury.

Year-round training and conditioning

Practicing strength and stretching exercises can help athletes with balance and coordination.  

Proper warm-up before a competition

Allow yourself time to warm up before competition with sport-specific exercises and stretches. A proper warm-up is important for preventing muscle strains. 

Practice landing skills and direction changes

Many athletes don't bend their knees enough when changing direction or landing from a jump. This puts more pressure on the legs and increases the risk of an ACL injury. This is especially vital for women, as they don't bend their knees as much as men do when landing a jump.

Our experts recommend the following when landing after jumping: 

  • Bend your knees when landing. As the knees bend during landing, make sure they travel in a straight path. Don't let them move closer together.  
  • Land softly on the balls of your feet and roll back onto the heels. 
  • Keep your knees and hips aligned and your upper body upright. Don't bend too far forward or backward at the hips as you land. 
  • Try not to land on one foot. If this isn't possible, bring the other foot down as soon as possible to distribute weight evenly. 

Improve agility

In sports like soccer and basketball, sudden changes in movement are part of the game. This can put athletes at risk for ACL injuries. Practice proper form in agility exercises, such as cutting. 

Work on muscle strength

Focus on lower body and core strengthening. A strong core and hips help athletes improve balance. Plus, strong hamstrings and quadriceps work together to bend or straighten the leg. Strengthening these targeted areas can help reduce the risk of an ACL injury. 

What exercises can reduce risk of an ACL injury? 

Exercises that strengthen your legs may help lower the risk of an ACL injury. Some examples include: 

  • Quad sets.
  • Straight leg raises.
  • Backward leg raises. 
  • Hip abduction. 
  • Squats. 
  • Wall sits. 
  • Reverse lunges. 
  • Bridges (short leg and long leg). 
  • Planks and side planks.

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What Are the Signs and Symptoms of an ACL Injury? 

ACL injury symptoms can vary. Many people who injure their ACL hear a popping noise in their knee. Other common symptoms of ACL sprains or tears include: 

  • Swelling.
  • Tenderness. 
  • Less range of motion. 
  • Trouble walking.
  • Pain.

Some people have a lot of pain, while others can walk around for a few hours after the injury. But as the swelling in your knee increases, it's harder to walk and you lose range of motion. 

When should I see a doctor about my ACL injury symptoms?

If you think you've injured your ACL, you should see a doctor right away. The best time to diagnose an acute ACL tear is within the first hour of injury — before the knee swells, if possible. 

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How Do You Diagnose an ACL Tear or Injury? 

When you see your doctor, they'll get a complete history of your ACL injury and ask you: 

  • How the tear happened. 
  • If your knee hyperextended.
  • If you heard a pop. 
  • Where — and how much — your knee hurts. 
  • If your knee feels unstable. 
  • If you've injured your knee before. 

What to expect during your visit

The doctor will also do a physical exam or test of your knee to assess the stability of the ligaments. They can diagnose an ACL tear by applying force to the knee and feeling for abnormal motion. 

The doctor should also evaluate the uninjured knee for comparison.

Tests to diagnose an ACL injury

Your doctor may order tests to find out the extent of the ACL injury, such as:

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How Do You Treat an ACL Injury or Tear? 

UPMC offers many options for treating ACL tears and injuries, ranging from nonsurgical to ACL reconstruction surgery. 

The goal of ACL treatment is to stabilize the knee and restore the range of motion. Your doctor will consider the following when recommending treatment:

  • Your age. 
  • Your activity level. 
  • Degree of injury. 

UPMC also offers an ACL Injury Prevention Program for athletes looking to return to their sport following an ACL injury or to learn how to prevent one. 

Nonsurgical treatment for ACL injuries 

Minor ACL injuries are often treated without surgery. Your doctor may suggest you use a protective brace and physical therapy.

To treat a minor ACL tear, your doctor may advise you to: 

  • Apply ice to the knee a few times a day. 
  • Elevate the knee above the level of the heart. 
  • Compress the knee with a bandage or wrap. 
  • Practice gradual muscle strengthening exercises. 
  • Reduce or halt activity for several weeks. 
  • Take anti-inflammatory drugs — such as ibuprofen — to reduce swelling and speed up recovery. 

Surgery for ACL tears 

A full ACL tear will not heal on its own. If you live an active lifestyle or play sports, surgery to repair the ligament may be the best option. Without surgery, your knee may be unstable and increase your risk for future injuries.  

Most ACL surgeries are done in an outpatient (ambulatory) setting, which means you can go home the same day as your surgery.

What does the doctor do during ACL surgery?

Typical surgical techniques for ACL tears and knee injuries include:

  • ACL repair or rebuilding. Your surgeon repairs the original ligament to promote healing.
  • ACL reconstruction. Your surgeon rebuilds the ligament using tissue from your body or a donor.

Orthopaedic surgeons at UPMC Sports Medicine perform anatomic ACL reconstruction, with a goal of replicating the knee's original anatomy.

Measurements of the uninjured ACL are taken to mimic this as closely as possible.

Recovery from ACL surgery

After ACL surgery, you'll have to eliminate all weight-bearing activities. Depending on the type of ACL tear, your symptoms, and your health history, recovery can range from 3 to 9 months. This is especially important for those hoping to return to physical activities.

You must follow your doctor's orders to rest. Not resting can lead to more knee problems and related complications.

Physical therapy (PT) is also vital to healing from an ACL tear or injury. The goal of PT is to restore your range of motion and stabilize the knee. Your physical therapist will give you exercises to:

  • Strengthen your quadriceps and hamstring muscles.
  • Restore range of motion.

You can complete most of the exercises at home or in the gym.

How effective is treatment for ACL injuries?

Due to the physical nature of sports, athletes are 15 times more likely than non-athletes to reinjure their ACL after surgery. About 30% of athletes will reinjure their ACL within 24 months of surgery.

Compared to male athletes, female athletes are: 

  • Four times more likely to suffer a graft re-tear. 
  • Six times more likely to injure the other side of the ACL. 

UPMC ACL Injury Prevention Program helps athletes with ACL injuries get back in the game. The team will work with you to create a treatment plan to prevent reinjuring your ACL.

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