How to tear acl?

The anterior cruciate (an TEER ier KROO she at) ligament (ACL) is one of four main ligaments in the knee. Ligaments are tissues that hold the bones together. The ACL is in the middle of the knee between the shinbone (tibia) and the thighbone (femur). The ACL provides support to the knee when pivoting, jumping and making quick turns. There is another area of tissue in the knee called the meniscus (men IS cus). The meniscus is the rubbery cartilage disc between the shin (tibia) and thighbone (femur). It acts as a “shock absorber” in the joint. When the ACL tears, there may often be an injury to the meniscus.

Contents

Common Causes of Injury

The most common cause of an ACL tear is a non-contact pivoting injury. Most often these injuries occur in sports, such as basketball, soccer, football, etc.

Symptoms

Your child may hear or feel a pop at the time of injury. He or she may also complain of knee pain. The child’s knee may swell after an injury to the ACL. The tear does not keep your child from walking, but it may make the knee feel like it will give out.

Diagnosis

After an injury, your child’s knee may be very swollen. If the doctor thinks there may be an injury to the ACL, he may suggest your child wait a few days before scheduling an appointment. This allows the swelling to go down. It will make the exam easier and less painful.

If the doctor examines the knee and feels unsteadiness or abnormal movement, there may be damage to the ACL. In some cases, your child’s doctor may need X-rays to check for injury to the bone. The ACL and meniscus are made of soft tissue.

A tear in soft tissue will not show up on an x-ray, so the doctor may order an MRI (magnetic resonance imaging) test. This test allows the doctor to see if there is a tear in the ACL or injury to the meniscus.

Initial Treatment

  • RICE: Rest, Ice, Compression, Elevation
  • Knee brace
  • Crutches
  • Pain relievers, such as Motrin® or Tylenol®: Motrin® helps reduce pain and swelling; Tylenol® may also help with discomfort. Motrin can often be taken every six hours and Tylenol can be taken every four hours. These medicines can be alternated every three hours as needed for pain control.

Surgery

When the ACL tears, the ends cannot be sewn back together. The ligament needs to be rebuilt to allow the child to function in sports or activities that are more physical. Surgery to rebuild the ACL is called arthroscopic (ar thro SKO pic) ACL reconstruction. The doctor rebuilds the torn ligament using part of your child’s hamstring or other tissue. It is usually an outpatient surgery. Younger children who have the surgery may stay overnight to help manage their pain and swelling after surgery. An older child can go home after surgery when he or she is able to drink and to use crutches or a walker safely.

After surgery

Brace and Crutches

After surgery, your child will use crutches and wear a hinged knee brace. Your child will be taught how to use the brace and crutches. It is very important that he or she use the brace and crutches as instructed.

Ice

You or your child will also be taught how to use the Polar Ice device. It is recommended that your child use the machine regularly for the first 24-48 hours after surgery to help decrease swelling. After 48 hours, you may begin using it off and on at times for 30 minutes, 3-4 times every day until the swelling lessens.

Pain Medicine

Your child will get a prescription for pain medicine. The doctor may recommend that you add Motrin® for pain relief as well. Motrin® will help with swelling and will help your child stop using the pain medicine faster.

Exercises

Your child will get exercises to do. The muscles at the site of surgery will be weak, but it is important for your child to do these exercises. They help build up the strength of the leg muscles. This helps with healing.

At the first appointment after surgery, your child will get a prescription for physical therapy. The child should start physical therapy as soon as possible after the first follow-up appointment (usually one week after surgery). The exercises at home and in physical therapy will help your child recover quicker. They will help reduce swelling and improve the range of motion. See Helping Hand HH-II-50, ACL Exercises.

Follow-up

Your child’s first follow-up appointment will be one week after surgery. At this time the incisions will be checked and any dressings will be removed. You can talk to your child’s care team about amount of pain. You will get the prescription for physical therapy.

When to Call the Doctor

Call the Orthopedic clinic at 614-722-5175 any time with questions or if your child has:

  • Pain that gets worse
  • A new rash
  • Fever higher than 101° F by mouth
  • Chills
  • Nausea or vomiting
  • Drainage of any kind from the incision
  • More redness and warmth at the incision

Expectations for Recovery

In most cases, it will take 6 to 9 months of recovery until your child can return to normal sports or activities. Your doctor and physical therapist will work with your child to increase the strength and motion of the knee. Your child’s doctor has a specific set of rules for activities following an ACL reconstruction surgery, and the physical therapist will follow this timeline. It is important for your child to not do activities until the doctor or physical therapist approves. This will allow the ACL to fully heal.

Anterior Cruciate Ligament (ACL) Tear (PDF)

HH-I-341 4/17 Copyright 2017 Nationwide Children’s Hospital

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.

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.

A recent study published online in Pediatrics has confirmed that ACL injuries in children and adolescents are on the rise. The study authors found a 2.3 percent annual increase from 1994 to 2013 in the number of ACL tears in patients 6 to 18 years old. Females had significantly higher rates of injury in the younger ages, while males demonstrated higher incidence in the 17- to 18-year-old age group.

Understanding your risk for suffering an ACL tear is the first step to prevention. At Children’s Hospital of Philadelphia (CHOP), Dr. Theodore Ganley and our sports medicine team wanted to counsel our patients and families about each individual athlete’s risk of an ACL injury based on their sex and the sports they play. To start, we combined the data reported in every article published worldwide on the incidence of ACL tear (called a meta-analysis). Using this information, we were able to calculate the risk of ACL tear in each season of sport by sex.

Calculate your risk

  1. Circle the sports you play in the table below. For each sport, find your risk for tearing your ACL in a single season based on your sex.
  2. Multiply this risk by the number of seasons of the sport you play each year to find your risk per year for each sport.
  3. Repeat for each sport you play, and add up your yearly risk for each sport to get your total overall yearly risk of ACL tear.

For example:

(Sport A risk per season from table) x (Sport A seasons played per year) = Sport A risk per year

(Sport B risk per season from table) x (Sport B seasons played per year) = Sport B risk per year

(Sport A risk per year) + (Sport B risk per year) = Combined risk per year of Sport A and Sport B together

This table is simplified from the published version. See the original published table here. Our numbers are most applicable to the average high school athlete since most of the data came from published incidence rates on this population. Your risk may vary from the rates shared here based on your level of competition, exposures per season, and age.

Using our table, “ACL Tear Risk per Season by Sport and Sex,” we’re able to calculate that males who play one season each of football, basketball and baseball have a roughly 1 percent risk of tearing their ACL over the course of a single school year. A female who plays soccer all four seasons has a 4.4 percent chance of tearing her ACL each year.

How can I lower my risk for an ACL tear?

ACL injuries happen when an athlete:

  • Stops suddenly, slows down or changes direction while running
  • Jumps or lands incorrectly
  • Is tackled, as in football
  • The primary prevention strategies to avoid ACL injuries are to:

Avoid overuse and risks associated with participation in multiple sports on multiple teams in the same season. The American Academy of Pediatrics recommends encouraging children to try a variety of sports, limiting participation in sports to five days a week, and taking a combined two to three months off per year from each specific sport (see the AAP for more recommendations)

Prepare your knee to better withstand injury-causing behaviors. A prevention program will include specific stretches, warm ups, and strength and agility training that prepares the muscles and tendons in the knee for practice and games. These prevention strategies can be implemented as a pre-practice warm up or daily on your own using the Ready, Set, Prevent program.

Anterior Cruciate Ligament (ACL) Tears

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What Is the Anterior Cruciate Ligament?

The anterior cruciate ligament (ACL) is one of the ligaments in the knee joint. A ligament is a tough, flexible band of tissue that holds bones and

together.

The ACL connects the bottom of the thighbone (femur) to the top of the shinbone (tibia). The ACL helps keep the knee stable.

What Is an ACL Tear?

The anterior cruciate (pronounced: KROO-she-ate) ligament can tear if an injury stretches it too much. The tear might be partial (through a part of the ACL) or complete (all the way through the ACL).

What Are the Signs & Symptoms of an ACL Tear?

Most people who tear their ACL feel pain and a “pop” in their knee when the injury happens. Their knee usually gets swollen soon after the injury. After the swelling goes down, someone with an ACL tear usually can walk. But the knee may feel unstable and can “give way” and make the person stumble or fall.

What Causes an ACL Tear?

Most ACL tears happen during athletic activity. For example when someone:

  • changes direction or twists the knee while running
  • jumps and lands in a way that twists the knee

The ACL also can tear if the knee is hit forcefully from the side.

Who Gets ACL Tears?

ACL tears happen most often during sports that have turning, cutting, and pivoting movements like skiing, soccer, football, basketball, and tennis. Girls tear their ACL more often than guys do.

How Is an Anterior Cruciate Ligament Tear Diagnosed?

To diagnose a torn ACL, health care providers ask about the injury and do a physical exam. During the exam, the health care provider presses on the knee and legs and moves them in certain ways. These tests can show if the ACL is torn.

Health care providers also might order imaging tests like:

  • X-rays to check for injuries to the bones
  • an MRI to check the extent of an ACL tear and to see if the knee has other injuries

How Is an ACL Tear Treated?

Right after the injury, an ACL tear is treated with:

  • RICE: Rest, Ice, Compression (with an elastic bandage), and Elevation (raising the knee)
  • over-the-counter pain medicine such as acetaminophen (Tylenol or store brand) or ibuprofen (Advil, Motrin, or store brand)

Most partial tears can be treated with bracing and physical therapy (PT). A person might need to use crutches as the tear heals.

Some complete ACL tears need surgery. The need for surgery depends on many things, including:

  • the type of the activities (or sports) the person wants to do
  • if the person is an athlete
  • age
  • other injuries to the knee
  • if the knee “gives way” or feels unstable

What Happens During Surgery for a Torn ACL?

ACL reconstruction surgery uses a graft (piece of tissue) to reconstruct (rebuild) the ACL. The graft can be a tendon, from the patient’s own body (called an autograft) or from someone else who donated the tendon (called an allograft).

ACL repair surgery is usually done arthroscopically. This type of surgery is done using a tiny camera (called an arthroscope) and small instruments that are inserted through small incisions (cuts).

Recovery from ACL surgery can take 6–12 months. If you have an ACL repair, you may use crutches and a leg brace after surgery. Some people might need a knee brace after that.

Physical therapy is important to help the knee heal. PT helps to:

  • improve range of motion and flexibility
  • regain strength in the knee, thigh, and shin muscles
  • reduce pain and swelling
  • improve balance

How Can I Prevent Another ACL Tear?

If you had an ACL tear, there’s a higher chance it might happen again. Training programs may help you avoid another ACL tear. These focus on neuromuscular training (NMT). NMT teaches movement patterns that lower the risk of injury, especially while jumping, landing, and changing direction. NMT programs include stretching, plyometrics (jump training), and balance training.

Ask your care team if an NMT program, like PEP training, is right for you.

What Should I Do?

Recovering from an ACL tear takes time. It’s normal to feel angry, frustrated, or down, especially if you can’t play a sport you love.

While you heal, try to find other ways to stay involved in sports, such as keeping score or being a team manager. Or, if you want to develop new talents besides playing sports, this is a good time to explore a new hobby like playing the guitar, painting, or drawing.

To get the best treatment possible:

  • Go to all follow-up visits and physical therapy appointments as directed.
  • Follow the care team’s instructions for at-home exercises.

Reviewed by: Alvin Su, MD Date reviewed: January 2019

ACL Tear: Causes and Risk Factors

Anterior cruciate ligament (ACL) knee injuries often happen suddenly and without warning. While any active adult can sustain an ACL injury, there are certain situations, activities, and risk factors that increase the likelihood of it occurring.

Causes of ACL Tears

An ACL tear is usually sudden and is regularly seen in both contact and non-contact sports. It often occurs:

  • As a result of cutting or pivoting maneuvers, when an athlete plants a foot and suddenly shifts direction
  • When a person lands on one leg, such as when jumping in volleyball or basketball
  • When the knee is hit directly, especially when it is hyper-extended or bent slightly inward
  • During a sudden slowing or stopping from running, which can cause the ligament to hyper-extend
  • Through repeated stress to the knee, which can cause the ligament to lose elasticity (like a stretched out rubber band)
  • When the knee is bent backward or twisted, which can occur during a fall or landing a jump awkwardly

See Understanding Knee Hyperextension

Sports injuries are the most common causes of ACL tears, however, the ACL can be injured during any trauma, such as during a car accident, falling off a ladder, or missing a step on a staircase.

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Risk Factors: ACL Tears

While anyone can injure their ACL, certain factors can put an individual at higher risk:

  • Female sex. The rate of ACL injuries is three times higher in female athletes than in males.1 While the exact reason is unknown, some reasons include differences in muscle conditioning, control, and strength.
  • Participation in certain sports. ACL tears commonly occur in sports such as basketball, soccer, football, volleyball, downhill skiing, lacrosse, and tennis. These sports require frequent and sudden deceleration, such as cutting, pivoting, or landing on one leg.
  • Previously torn ACL. The risk of re-tearing a previously repaired ACL is approximately 15% higher than the risk of tearing a normal ACL.2 One study notes that this risk is highest in the first year after the initial injury. The risk of an ACL tear in the opposite knee is also higher once the injury has occurred in the first.
  • Age. ACL tears are most common between the ages of 15 and 45, mostly due to the more active lifestyle and higher participation in sports.

Having a risk factor does not mean a person will have an ACL injury in his or her lifetime.

Why Are Women at higher risk for ACL Injuries?

Women tend to injure their ACL more often than men because of differences in:

  • Strength
  • Anatomy
  • Genetics
  • Jumping and landing patterns

See Guide to Knee Joint Anatomy

Experts have recently gained a better understanding of women’s jumping and landing patterns and how they relate to ACL injuries. A particularly vulnerable and common landing position for ACL tears involves the knee and hip in an extended (straight) position when the athlete forcefully places an inward, or valgus, force on the knee.3

See Symptoms of Knee Hyperextension

In This Article:

  • Anterior Cruciate Ligament (ACL) Tears
  • ACL Tear Symptoms
  • ACL Tear: Causes and Risk Factors
  • ACL Tear Diagnosis
  • ACL Tear Treatment Options
  • ACL Tear Surgical Repair

ACL Tear Prevention

Recent attention has focused on prevention of ACL injuries, especially in young females who participate in high-risk sports.

  • High-intensity jumping exercises
  • Biomechanical analysis with direct feedback to the athlete to improve position and movement patterns, including cutting and landing techniques
  • Strength training, especially of the hamstring and gluteus maximus muscles
  • Proprioceptive training, such as use of a wobble-board, to improve muscle strength, balance, and reaction times

See Advanced Exercises to Restore Proprioception

Successful programs have been initiated at least 6 weeks prior to the sports season, followed by an in-season maintenance program that may replace the traditional warm-up.

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In addition to changes in training, changes in footwear may decrease the chance of ACL injuries. Factors such as the length, shape, and number of cleats a shoe has may affect the risk of ACL injuries.4 The type of surface a person plays on, such as turf or grass, may also affect the risk of an ACL tear. Speak with a health care provider for more information about playing conditions.

While some athletes wear knee braces to prevent ACL injuries, current clinical evidence does not support their use in ACL prevention.

  • 1.Sutton KM, Bullock JM. Anterior cruciate ligament rupture: differences between males and females. J Am Acad Orthop Surg. 2013 Jan;21(1):41-50. doi: 10.5435/JAAOS-21-01-41. Review. PubMed PMID: 23281470.
  • 2.Wiggins AJ, Grandhi RK, Schneider DK, Stanfield D, Webster KE, Myer GD. Risk of Secondary Injury in Younger Athletes After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis. Am J Sports Med. 2016;44(7):1861-76.
  • 3.Voskanian N. ACL Injury prevention in female athletes: review of the literature and practical considerations in implementing an ACL prevention program. Curr Rev Musculoskelet Med. 2013;6(2):158-63.
  • 4.Silva DCF, Santos R, Vilas-Boas JP, Macedo R, Montes AM, Sousa ASP. Influence of Cleats-Surface Interaction on the Performance and Risk of Injury in Soccer: A Systematic Review. Appl Bionics Biomech. 2017;2017:1305479. doi:10.1155/2017/1305479

Anterior Cruciate Ligament (ACL) Injuries

The anterior cruciate ligament (ACL) is one of four major ligaments of the knee. ACL injuries are common in sports that involve sudden changes of direction, such as football and soccer, but they can also occur during regular daily activities.

More than 400,000 ACL injuries occur every year in the United States in active people and athletes. Often, the injury can lead to long-term problems in stability and degeneration.

When the ACL is injured, the pain can be excruciating — or minor — but the result is debilitating. If you have — or suspect you have — an ACL injury, we can help.

We treat all forms of ACL stretches, tears and ruptures successfully because of our years of experience and our multidisciplinary approach to ACL treatment. We have extensive experience with children and have treated ACLs in infants. We involve all areas of our health care team in assessing your condition — and getting you better and fully functioning as soon as possible.

We have experience with all ACL graft options, including autographs (tissue transfer from your body) and allographs (tissue transfer from a donor) and can advise you on the best choice for you depending on your age and activity level.

If your meniscus is injured, the sooner you are treated, the more likely a repair (not removal) will be possible. If your meniscus is removed when you are a teenager, your risk of getting arthritis at an early age skyrockets. We are experts at meniscus repair.

Note: If you have suffered a trauma — whether it’s from a fall or a sports injury — it’s important to seek treatment as soon you can, or you could risk further complications such as stiffness, prolonged pain or scar tissue in the joint. Getting that diagnosis quickly and accurately means we can treat you while the injury is simpler to treat.

Some people have minimal to no pain, minimal swelling and feel like they could play, but be careful.

The typical symptoms of an ACL tear or injury include:

  • A loud popping sound at the moment of injury
  • Inability to bear weight on your leg
  • Instability
  • Severe knee pain at the moment of the injury and more pain when you try to stand
  • Swelling

Diagnosis

When you come to the University of Michigan:

  • We will take your medical history, ask you about your pattern of symptoms and conduct a clinical exam.
  • Most ACL tears (more than 95%) can be diagnosed during a physical exam — your exam may require x-rays
  • We may order an MRI to see if there is additional damage to bone, cartilage or menisci.

Then we will use all of this information to develop an individualized treatment plan for you.

Treatment

Non-surgical Treatment for an ACL Injury

Small ACL stretches or tears may require a brace and/or physical rehabilitation. We work closely with the experts in our Rehabilitation area to give you a plan of treatment that will eliminate pain, stabilize your joint and prevent further damage. Partial tears may not require surgery if a lifestyle change is acceptable.

Surgery for an ACL Injury

We consider non-surgical treatments first, but if the tear is complete and the knee is unstable, or the knee doesn’t heal with non-surgical treatment, surgery may be necessary. The ACL cannot heal on its own because there is no blood supply to this ligament. Surgery is usually required for athletes because the ACL is needed in order to safely perform the sharp movements that are required in sports.

We are very experienced in the three major types of ACL reconstructive surgery that are done arthroscopically by inserting a specially designed illuminated scope into the joint through a small incision:

  • Patella tendon-bond autograft – With this surgery, we remove the central one-third of the patella tendon along with a piece of bone at the attachment sites at the kneecap and tibia.
  • Hamstring autograft – We take two tendons from the hamstring muscles and wrap them together to form the new ACL.
  • Quadriceps tendon grafts – These grafts are excellent for revision surgery, pediatric ACL tears and PCLs.
  • Grafts – We do both allografts (in which we use a donor tissue from a tissue bank) and autographs (in which we would use your hamstring tendon or the middle third of your patella tendon).

We also do partial and full knee replacements when necessary.

Before and after surgery, you will benefit greatly from rehabilitation to strengthen the muscles surrounding your ACL, stabilize your knee joint, reduce swelling and increase range of motion. If surgery is performed before you regain full range of motion and swelling is reduced, it can be difficult to get back to normal after surgery. We will work closely with our excellent Rehabilitation team to develop a treatment plan just for you.

Contact Us / Make an Appointment

  • MedSport, 877-877-9333, or 734-930-7400
  • Orthopaedics, 734-936-5780
  • Physical Medicine and Rehabilitation (PMR), 734-936-7175

Selecting a health care provider is a very important decision. Because we are highly experienced in successfully treating ACL tears and other knee injuries, we would like to help you explore your options. Visit our Contact Us page to see a list of Musculoskeletal Call Centers. Our staff will be glad to talk with you about your options and how we can help.

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The anterior cruciate ligament (ACL) is one of the ligaments in the knee joint. A ligament is a tough, flexible band of tissue that holds bones and

together.

The ACL connects the bottom of the thighbone (femur) to the top of the shinbone (tibia). The ACL helps keep the knee stable.

The anterior cruciate (KROO-she-ate) ligament can tear if an injury stretches it too much. The tear might be partial (through a part of the ACL) or complete (all the way through the ACL).

Most people who tear their ACL feel pain and a “pop” in their knee when the injury happens. Their knee usually gets swollen soon after the injury. After the swelling goes down, someone with an ACL tear usually can walk. But the knee may feel unstable and can “give way” and make the person stumble or fall.

What Causes ACL Tears?

Most ACL tears happen during athletic activity. For example when someone:

  • changes direction or twists the knee while running
  • jumps and lands in a way that twists the knee

The ACL also can tear if the knee is hit forcefully from the side.

ACL tears happen most often during sports involving turning, cutting, and pivoting like skiing, soccer, football, basketball, and tennis. Women tear their ACL more often than men. This is most likely due to different anatomy.

To diagnose a torn ACL, health care providers ask about the injury and do a physical exam. During the exam, the health care provider presses on the knee and legs and moves them in certain ways. These tests can show if the ACL is torn.

Imaging tests that might be done include:

  • X-rays to check for injuries to the bones
  • an MRI to check the extent of an ACL tear and to see if the knee has other injuries

Right after the injury, an ACL tear is treated with:

  • RICE: Rest, Ice, Compression (with an elastic bandage), and Elevation (raising the knee)
  • over-the-counter pain medicine such as acetaminophen (Tylenol or store brand) or ibuprofen (Advil, Motrin, or store brand)

Most partial tears can be treated with bracing and physical therapy (PT). A person might need to use crutches during recovery.

Some complete ACL tears will need surgery. Whether someone has surgery depends on many things, including:

  • the type of the activities (or sports) the person wants to do
  • if the person is an athlete
  • age
  • other injuries to the knee
  • if the knee “gives way” or feels unstable

ACL reconstruction surgery uses a graft (piece of tissue) to reconstruct (rebuild) the ACL. The graft can be a tendon, with or without bones attaching to it, from the patient’s own body (called an autograft) or from someone else who donated the tendon (called an allograft).

ACL repair surgery is usually done arthroscopically. This type of surgery is done using a tiny camera (called an arthroscope) and small instruments that are inserted through small incisions (cuts).

Recovery from ACL surgery can take 6–12 months. A person may use crutches and a leg brace after surgery, and might need a knee brace after that.

Physical therapy is important to help the knee heal. PT helps to:

  • improve range of motion and flexibility
  • regain strength in the knee, thigh, and shin muscles
  • reduce pain and swelling
  • improve balance

How Can We Prevent Another ACL Tear?

Having an ACL tear puts someone at higher risk for another one. Training programs may help your child avoid another ACL tear. These focus on neuromuscular training (NMT). NMT teaches movement patterns that lower the risk of injury, especially while jumping, landing, and changing direction. NMT programs include stretching, plyometrics (jump training), and balance training.

Ask your care team if an NMT program is right for your child.

How Can Parents Help?

Recovering from an ACL tear takes time. It’s normal for kids with ACL tears to feel angry, frustrated, or down, especially if they can’t play a sport they love. Help your child find ways to stay involved in sports, such as keeping score or being a team manager. Or, if your child wants to do something besides sports, help him or her try a new hobby like playing the guitar, painting, or drawing.

To help your child get the best treatment possible:

  • Go to all follow-up visits and physical therapy appointments as directed.
  • Help your child follow the care team’s instructions for at-home exercises.

Reviewed by: Alvin Su, MD Date reviewed: January 2019

PMC

Anterior cruciate ligament (ACL) injury is one of the most commonly seen injuries in sport and has a devastating influence on patients’ activity levels and quality of life. Gottlob et al21 estimated that approximately 175 000 primary ACL reconstruction surgeries were performed annually in the USA with an estimated cost of over US$2 billion. Complete ACL rupture can induce other pathological knee conditions including knee instability, damage to menisci and the chondral surface, and osteoarthritis. Studies have repeatedly shown that patients with complete ACL rupture have chronic knee instability and secondary damage to menisci and chondral surfaces.19,28,30

ACL injuries that occur without physical contact between athletes are referred to as non‐contact ACL injuries8,17,18 and most occur through a non‐contact mechanism of injury in sports in which sudden deceleration, landing and pivoting manoeuvres are repeatedly performed.8 Female athletes had a higher incidence of ACL injuries compared with their male counterparts.2,18 Studies have shown that the incidence in female athletes is two to eight times higher than in males in soccer, basketball and volleyball.2,7,18,22,25,26,36

As with other sports injuries, understanding injury mechanisms is a key component of preventing non‐contact ACL injuries.36a The research effort to determine the risk factors for sustaining non‐contact ACL injuries is increasing as concerns grow about the larger number of incidents, the greater treatment costs and the serious consequences of non‐contact ACL injuries. Prospective cohort studies commonly use epidemiological research designs for determining injury and disease risk factors,48 and are being used for determining the risk factors for sustaining non‐contact ACL injuries.24 The results of epidemiological studies with cohort designs, however, are descriptive in nature and do not examine the cause‐and‐effect relationship between identified risk factors and the injury.48 Without a good understanding of the injury mechanisms, the risk factors for sustaining non‐contact ACL injuries identified from epidemiological studies could be misinterpreted and lead to the selection of non‐optimal injury prevention programs. The purpose of this review was to examine biomechanical studies relating to the mechanisms of non‐contact ACL injuries.

Mechanically, ACL injury occurs when an excessive tension force is applied on the ACL. A non‐contact ACL injury occurs when a person themselves generates great forces or moments at the knee that apply excessive loading on the ACL. Therefore, an understanding of the mechanisms of ACL loading during active human movements is crucial for understanding the mechanisms and risk factors for non‐contact ACL injuries. Berns et al5 investigated the effects of combined knee loading on ACL strain on 13 cadaver knees. The strain of the anterior medial bundle of the ACL was recorded using liquid mercury strain gauges at 0° and 30° knee flexion. The results of this study showed that the anterior shear force on the proximal end of the tibia was the primary determinant of the strain in the anterior medial bundle of the ACL, while neither pure knee internal‐external rotation moment or pure knee valgus‐varus moment had significant effects on the strain of the anterior medial bundle of the ACL. The results of this study further showed that anterior shear force at the proximal end of the tibia combined with a knee valgus moment resulted in a significantly greater strain in the anterior medial bundle of the ACL than did the anterior shear force at the proximal end of the tibia alone.

Markolf et al39 also investigated the effects of anterior shear force at the proximal end of the tibia and knee valgus, varus, internal rotation and external rotation moments on the ACL loading of cadaver knees. A 100‐N anterior shear force and 10‐Nm knee valgus, varus, internal rotation and external rotation moments were added to cadaver knees. The ACL loading was recorded as the knee was extended from 90° of flexion to 5° hyperextension. The results of this study showed that an anterior shear force on the tibia generated significant ACL loading, while the knee valgus, varus and internal rotation moments also generated significant ACL loading only when the ACL was loaded by the anterior shear force at the proximal end of the tibia. The results of this study further showed that the ACL loading due to the anterior shear force combined with either a valgus or varus moment to the knee was greater than that due to the anterior shear force alone, while the ACL loading due to the anterior shear force combined with a knee external rotation moment was lower than that due to anterior shear force alone. The knee valgus and external rotation moment loadings are elements of dynamic valgus that many current ACL injury prevention programs are trying to avoid.24 The results of the study by Markolf et al39 also showed that ACL loading due to the combined knee varus and internal rotation moment loading was greater than that due to either knee varus moment loading or internal rotation moment loading alone, and that the ACL loading due to combined knee valgus and external rotation moment loading was lower than that due to either knee valgus or external rotation moment loading alone. Finally, the results of this study showed that the ACL loading due to the anterior shear force and knee valgus, varus and internal rotation moments increased as the knee flexion angle decreased.

Fleming et al20 studied the effects of weight bearing and tibia external loading on ACL strain. They implanted a differential variable reluctance transducer on the anterior medial bundle of the ACL of 11 subjects. ACL strains were measured in vivo when a subject’s leg was attached to a knee loading fixture that allowed independent application of anterior‐posterior shear force, valgus‐varus moments and internal‐external rotation moments to the tibia and simulation of a weigh‐bearing condition. The anterior shear force was applied on the proximal end of the tibia from 0 N to 130 N in 10‐N increments. The valgus‐varus moments were applied to the knee from −10 Nm to 10 Nm in 1‐Nm increments. The internal‐external rotation moments were applied to the knee from −9 Nm to 9 Nm in 1‐Nm increments. The knee flexion angle was fixed at 20° during the test. The results of this study showed that ACL strain significantly increased as the anterior shear force at the proximal end of the tibia and the knee internal rotation moment increased, while knee valgus‐varus and external rotation moments had little effect on ACL strain under the weight‐bearing condition.

The above‐mentioned studies consistently showed that the anterior shear force at the proximal end of the tibia is a major contributor to ACL loading, while the knee valgus, varus and internal rotation moments may increase ACL loading when an anterior shear force at the proximal end of tibia is applied. According to these ACL loading mechanisms, a small knee flexion angle, a strong quadriceps muscle contraction or a great posterior ground reaction force can increase ACL loading.

Quadriceps muscles are the major contributor to the anterior shear force at the proximal end of the tibia through the patella tendon. Arms et al3 and Draganich and Vahey16 found that quadriceps force can significantly increase the in vitro ACL strain from 0° to 45° of knee flexion. Durselen et al15 showed that the applied quadriceps force causes the ACL to sustain a high level of strain from full extension to 30° of knee flexion and that the ACL strain then starts to decrease as the knee flexion angle increases to more than 30°. Beynnon et al6 had similar results in that the in vivo isometric quadriceps force significantly strained the ACL at knee flexions of 15° and 30° relative to the relaxed condition. Shoemaker et al50 showed that the quadriceps had a significant effect on the tibial anterior displacement and the ACL graft tension. The largest graft tension due to the quadriceps occurred at 35° of knee flexion. A recent study by DeMorat et al14 showed that a 4500‐N quadriceps muscle force could cause ACL injuries at 20° of knee flexion. Eleven cadaver knee specimens were fixed to a knee simulator and loaded with a 4500‐N quadriceps muscle force. Quadriceps muscle contraction tests at 400 N (Q‐400 tests) and KT‐1000 tests were performed before and after the 4500‐N quadriceps muscle force loading. Tibia anterior translations were recorded during the Q‐400 and KT‐1000 tests. All cadaver knee specimens were dissected after the tests to determine the ACL injury states. Six of the 11 specimens had confirmed ACL injuries (three complete ACL tears and three partial tears). All specimens showed increased tibia anterior translation in the Q‐400 and KT‐1000 tests.

Decreasing knee flexion angle increases the anterior shear force at the proximal end of the tibia by increasing the patella tendon‐tibia shaft angle. With a given quadriceps muscle force, the anterior shear force at the proximal end of the tibia is determined by the patella tendon‐tibia shaft angle, defined as the angle between the patella tendon and the longitudinal axis of the tibia.43 With a given quadriceps muscle force, the greater the patella tendon‐tibia shaft angle, the greater the anterior shear force on the tibia. Nunley et al43 studied the relationship between the patella tendon‐tibia shaft angle and the knee flexion angle with weight bearing. Ten male and ten female college students without a known history of lower extremity injuries were recruited as subjects. Sagittal plane x ray films were taken for each subject at 0°, 15°, 30°, 45°, 60°, 75° and 90° knee flexions bearing 50% of the body weight. Patella tendon‐tibia shaft angles were measured from the x ray films. Regression analyses were performed to determine the relationship between patella tendon‐tibia shaft angle and knee flexion angle, and compare the relationship between genders. The results of this showed that the patella tendon‐tibia shaft angle was a function of knee flexion angle with an increase in patella tendon‐tibia shaft angle as the knee flexion angle decreased, and that, on average, the females’ patella tendon‐tibia shaft angle was 4° greater than that of the males. The relationship between the patella tendon‐tibia shaft angle and knee flexion angle found by Nunley et al43 was consistent with those from other studies on the patella tendon‐tibia shaft angle under non‐weight‐bearing conditions.9,51,53

Decreasing knee flexion angle also increases ACL loading by increasing ACL elevation angle and deviation angle, defined as the angle between the longitudinal axis of the ACL and the tibia plateau and the angle between the projection of the longitudinal axis of the ACL on the tibia plateau and the posterior direction of the tibia, respectively.35 The resultant force along the longitudinal axis of the ACL equals the anterior shear force on the ACL divided by the cosines of the ACL elevation and deviation angles. The greater the ACL elevation and deviation angles are, the greater the ACL loading is with a given anterior shear force on the ACL. Herzog and Read23 show that a decrease in knee flexion angle results in a more vertical line of action of the ACL, which means an increase in the ACL elevation angle. Li et al35 determined the in vivo ACL elevation and deviation angles as functions of the knee flexion angle with weight bearing. Five young and healthy volunteers were recruited as subjects. The ACL elevation and deviation angles at 0°, 30°, 60° and 90° of knee flexion with weight bearing were obtained using individualised dual‐orthogonal fluoroscopic images and MR image‐based three‐dimensional models. The results of this study showed that both ACL elevation and deviation angles increased as the knee flexion angle decreased.

Several studies show that ACL loading increases as the knee flexion angle decreases. Arms et al3 studied the biomechanics of ACL rehabilitation and reconstruction and found that quadriceps muscle contraction significantly strains the ACL from 0° to 45° of knee flexion, but did not strain the ACL when knee flexion is greater than 60°. Beynnon et al6 measured the in vivo ACL strain during rehabilitation exercises and found that isometric quadriceps muscle contraction resulted in a significant increase in ACL strain at 15° and 30° knee flexions, while it resulted in no change in ACL strain relative to the relaxed muscle condition at 60° and 90° of knee flexion. Li et al33,34 investigated the quadriceps and hamstring muscle loading on ACL loading and showed that the in situ ACL loading increased as knee flexion angle decreased when the quadriceps muscles were loaded regardless of the hamstring muscle loading conditions.

The literature also shows that individuals at high risk of sustaining non‐contact ACL injuries have a smaller knee flexion angle during athletic tasks than individuals at low risk. Epidemiological studies show that female athletes are at higher risk of sustaining non‐contact ACL injuries than their male counterparts2,18,27,36,37,45,46,46a Recent biomechanical studies demonstrated that female recreational athletes exhibited small knee flexion angles in running, jumping and cutting tasks.12,38 Studies also demonstrate that female adolescent athletes had a sharply increased ACL injury rate after 13 years of age.49,54 A recent biomechanical study showed that female adolescent soccer players started decreasing their knee flexion angle during a stop‐jump task after 13 years of age.57 These results combined suggest that small knee flexion angle during landing tasks may be a risk factor for sustaining non‐contact ACL injuries.

Increasing peak posterior ground reaction forces during athletic tasks increases ACL loading by inducing an increased quadriceps muscle contraction. A posterior ground reaction force creates a flexion moment relative to the knee, which needs to be balanced by a knee extension moment generated by quadriceps muscles.58 As previously described, the quadriceps muscle contraction adds an anterior shear force on the proximal end of the tibia through the patella tendon. The greater the posterior ground reaction force is, the greater the quadriceps muscle force is, and the greater the ACL loading is (Yu et al, 2006). Cerulli et al11 and Lamontagne et al32 recently recorded in vivo ACL strain in a hop landing task. A differential variable reluctance transducer was implanted on the middle portion of the anterior‐medial bundle of the ACLs of three subjects. Subjects then performed the hop landing task in a biomechanics laboratory. Force plate, EMG and in vivo ACL strain were recorded simultaneously. The results of this study showed that the peak ACL strain occurred at the impact peak vertical ground reaction force shortly after initial contact between the foot and the ground. Yu et al59 demonstrated that peak impact vertical and posterior ground reaction forces occurred essentially at the same time. These results combined suggest that a hard landing with a great impact posterior ground reaction force may be a risk factor for sustaining non‐contact ACL injuries.

The literature shows that individuals at high risk of sustaining non‐contact ACL injuries have greater peak posterior ground reaction forces in athletic tasks. Chappell et al12 studied the lower extremity kinetics and the kinematics of college recreational athletes during landings in stop‐jump tasks. Their results showed that female recreational athletes had greater peak resultant proximal tibia anterior shear force and knee joint resultant extension moment during landings in stop‐jump tasks than male recreational athletes. Yu et al55 studied the immediate effects of a newly designed knee brace with a constraint to knee extension during a stop‐jump task. Their results showed that the female college recreational athletes had greater peak posterior ground reaction force during landing in the stop‐jump task than did their male counterparts. Yu et al59 showed that the resultant peak proximal tibia anterior shear force was positively correlated to the peak posterior ground reaction force.

That hamstring co‐contraction protects the ACL has been a long‐standing clinical concept because hamstring muscles provide a posterior shear force on the tibia that is supposed to reduce the anterior shear force on the tibia from the patellar tendon and thus unload the ACL. Recent scientific studies, however, did not support this concept. Li et al33 showed in a cadaver study that hamstring co‐contraction did not significantly decrease tibia anterior translation when the knee flexion angle was less than 30°. Beynnon et al6 found that the isometric hamstring co‐contraction of the hamstring muscles did reduce in vivo ACL strain between 15° and 60° of knee flexion. Kingma et al31 found that hamstring muscle activation increased only 1.3–2.0 times while knee extension moment increased 2.7–3.4 times when the knee flexion angle was between 5° and 50°, which did not suggest a hamstring recruitment pattern to reduce the ACL loading. O’Connor60 Pandy et al61 and Yu et al56 studied ACL loading using a modelling and computer simulation approach and all showed that the hamstring muscles did not reduce ACL loading at all when the knee flexion angle was small.

Although biomechanical studies showed that the knee valgus moment was not a major mechanism of ACL loading, a recent epidemiological study by Hewett et al24 reported that external knee valgus moment in a vertical drop landing‐jump task was a predictor of ACL injuries. A total of 205 high‐school soccer, basketball and volleyball players were followed for three competition seasons. Knee flexion and valgus angles at initial foot contact with the ground and the maximum knee flexion and valgus angles and maximum moments during the stance phase of the vertical drop landing‐jump task were recorded prospectively for every subject. Nine subjects sustained ACL injuries after three competition seasons. The results of this study showed that knee abduction angle at landing was 8° greater in ACL‐injured than in uninjured athletes, and that ACL‐injured athletes had a 2.5 times greater peak external knee valgus moment and a 20% higher peak vertical ground reaction force than did uninjured athletes. The results further showed that peak external knee valgus moment predicted anterior cruciate ligament injury status with 73% specificity, 78% sensitivity and a predictive r2 value of 0.88. The results of this study appear to suggest an association of knee valgus angle and moment with ACL injuries.

However, we may have to be cautious when interpreting the association of knee valgus angle and moment with non‐contact ACL injuries observed in the study by Hewett et al.24 The observed pre‐injury knee valgus moments of the nine subjects who suffered ACL injuries in this study were less than 0.12 Nm/body weight/standing height. The averaged body weight and standing height of the injured subjects in this study were 62 kg and 1.68 m. This means that the pre‐injury knee valgus moments of the nine subjects injured in this study were less than 12.5 Nm. These knee valgus moment loadings were similar to those in the studies by Berns et al,5 Markolf et al39 and Fleming et al20 that demonstrated that knee valgus loading did not significantly affect ACL loading unless a significant proximal tibia anterior shear force was applied. Further, several other studies in the current literature demonstrate that knee valgus moment loading alone cannot injure the ACL when the medial collateral ligament (MCL) is intact. Bendjaballah et al4 studied the effects of knee valgus‐varus moment loading on cruciate and collateral ligament loadings using a finite element model. Their results suggest that cruciate ligaments are not major valgus‐varus moment loading bearing structures when collateral ligaments are intact. Matsumoto et al40 investigated the roles of the ACL and MCL in preventing knee valgus instability using cadaver knees. Their results demonstrate that MCL is the major structure stopping medial knee space opening. Mazzocca et al41 tested the effect of knee valgus loading on MCL and ACL injuries. They found that the response of the ACL strain to knee valgus moment loading was minimal when the MCL was intact but significantly increased after the MCL rupture started due to knee valgus moment loading. Their results show that the ACL still had about 60% of its original strength after complete MCL rupture with medial knee space openings greater than 15 mm due to knee valgus moment loading. This study clearly demonstrates that there is unlikely to be a complete ACL rupture due to knee valgus moment loading without a complete MCL rupture (grade 3 injury), while clinical observation shows that most ACL non‐contact ACL injuries are not accompanied by significant MCL injuries. A recent study by Fayad et al62 showed that only five out of a total of 84 contact and non‐contact ACL injuries were accompanied by a complete MCL rupture. These studies combined suggest that knee valgus moment loading alone is not likely to be a major ACL loading mechanism that can result in ACL rupture or a major risk factor for sustaining non‐contact ACL injuries. More scientific studies are needed before we can confidently interpret the association of knee valgus angle and moment with non‐contact ACL injuries as a sole risk factor for sustaining non‐contact ACL injuries.

In summary, the current literature clearly suggests that sagittal plane biomechanics are the major mechanism of ACL loading. Decreased knee flexion angle and increased quadriceps muscle force and posterior ground reaction force causing an increased knee extension moment are requirements for increased ACL loading. Although the external knee valgus moment has been demonstrated to be associated with ACL injuries, the current literature contains no evidence that knee valgus‐varus and internal‐external rotation moments can produce non‐contact ACL injuries in and of themselves without these high sagittal plane forces.

Torn Anterior Cruciate Ligament(Torn ACL or ACL Injury)

How Are ACL Tears Treated? What Is the Recovery Time?

When surgery is considered, the ligament is not repaired but instead is reconstructed usually with minimally invasive surgery using an arthroscope. A variety of techniques may be used, and the orthopedic surgeon and patient usually discuss the options available before a decision as to what type of surgery is performed. The “new” ligament may be taken from part of the patellar tendon (the tendon that attached the quadriceps muscle to the tibia), from part of the hamstring tendon in the back of the knee, or it may be a donor or cadaver graft. Each option has its advantages and disadvantages.

Other structures in the knee may also be damaged in association with an ACL tear, including other ligaments and menisci (cartilage), and will often be repaired at the same time.

In children, instead of the ligament being torn, the ligament can pull a piece of bone off the tibial spine where it inserts. Surgery make be required to reattach the bony fragment instead of reconstructing the ligament.

Surgery is often the recommended option for patients with ACL injuries. The purpose of surgery is to return patients to their original level of activity. For patients who are sedentary and do not perform sports, or for those who perform light manual work and are involved in non-cutting sports like running and bicycling, nonoperative treatments of ACL injuries may be reasonable alternatives.

The international Knee Documentation Committee has four categories of activity:

  • Level 1 includes jumping, pivoting, and hard cutting.
  • Level 2 is heavy manual work or side-to-side sports.
  • Level 3 encompasses light manual work and non-cutting sports (such as running and cycling).
  • Level 4 is sedentary activity without sports.

Treatment without surgery may be an option for those in categories 3 and 4.

Surgery usually does not occur immediately after the injury but may be delayed three to four weeks or more. This time is used to allow for the initial swelling and bleeding from the injury to decrease and to plan for the operation.

Physical therapists are an important part of the treatment team and are usually involved in the planning phase before surgery and after surgery. Recovery is measured in months, and often rehabilitation and physical therapy are required after the ACL reconstruction. This commitment to rehabilitation is an essential part of a successful operation. In the time prior to surgery, many patients are encouraged to “pre-hab” their injured leg. When the knee is injured, the quadriceps muscle tends to weaken almost immediately, and it is important to minimize any loss in strength and range of motion in the knee.

Rehabilitation may take six to nine months to return to full activity:

  • In the first two to three weeks, the goal for physical therapy is to increase range of motion of the knee in a controlled fashion. Since the cruciate ligament graft needs time to heal in place, excessive flexing or bending is discouraged so that the graft doesn’t rip. The goal in the first couple of weeks is full extension (straightening) of the knee and 90 degrees flexion (bending).
  • In weeks three to six, the goal is to return full range of motion to the knee. Strengthening exercises may be considered and bicycles or stair-climbers are often used.
  • For the next many months, the goal is to increase strength and agility while maintaining range of motion. The progress is closely monitored by the surgeon and physical therapist, again to protect the reconstructed knee and to push the patient to the goal of full recovery.

The patient is often kept in a protective knee brace through much of the rehabilitation process to protect the grafted ACL from any undue stress. The brace use may be continued even after the ACL has healed, especially during sporting activities to decrease the risk of reinjury.

What’s the Treatment?

It depends on how badly you’ve been hurt. Here are some of the options your doctor may give you:

First aid. If your injury is minor, you may only need to put ice on your knee, elevate your leg, and stay off your feet for a while. You can reduce swelling by wrapping an ace bandage around your knee. Crutches can help to keep weight off your knee.

Medications. Anti-inflammatory drugs can help to reduce swelling and pain. Your doctor may suggest over-the-counter medications or prescribe something stronger. For intense pain, your doctor may inject your knee with steroid medication.

Knee brace. Some people with a damaged ACL can get by with wearing a brace on their knee when they run or play sports. It provides extra support.

Physical therapy. You may need this a few days a week to get your knee back in working order. During your sessions, you’ll do exercises to strengthen the muscles around your knee and help you regain a full range of motion. You may be sent home with exercise to do on your own.

Surgery. Your doctor may tell you that you need this if your ACL is torn badly, if your knee gives way when you’re walking, or if you’re an athlete. A surgeon will remove the damaged ACL and replace it with tissue to help a new ligament grow in its place. With physical therapy, people who have surgery can often play sports again within 12 months.

Physio Works – Physiotherapy Brisbane

Article by J. Miller, Z. Russell

ACL Injury

Source: http://www.englewoodortho.com

What is an ACL Injury?

Your ACL or anterior cruciate ligament is one of four knee ligaments that are critical to the stability of your knee joint. Your ACL is made of tough fibrous material and functions to control excessive knee motion by limiting joint mobility.

One of the most common problems involving the knee joint is an anterior cruciate ligament injury or ACL tear. Of the four major knee ligaments of the knee, an ACL injury or rupture is the most debilitating knee ligament injury.

What Causes an ACL Injury?

An ACL injury is usually a sports-related knee injury. About 80% of sports-related ACL tears are “non-contact” injuries. This means that the injury occurs without the contact of another player, such as a tackle in football.

Most often ACL tears occur when pivoting or landing from a jump. Your knee gives out from under you once you tear your ACL.

Female athletes are known to have a higher risk of an ACL tear while participating in competitive sports. Unfortunately, understanding why women are more prone to ACL injury is unclear. There are some suggestions it is biomechanical, strength and hormonally related. In truth, it is probably a factor of all three.

What Sports have a High Incidence of ACL Injuries?

Many sports require a functioning ACL to perform common manoeuvres such as cutting, pivoting, and sudden turns.

These high demand sports include football, rugby, netball, touch, basketball, tennis, volleyball, hockey, dance, gymnastics and much more. You may be able to function in your normal daily activities without a normal ACL, but these high-demand sports may prove difficult.

Therefore, athletes are often faced with the decision to undergo surgery in order to return to their previous level of competition. ACL injuries have been known to curtail many promising sporting careers.

What are the Symptoms of an ACL Injury?

The diagnosis of an ACL tear is made by several methods. Patients who have an ACL tear commonly sustain a sports-related knee injury.

They may have felt or heard a “pop” in their knee, and the knee usually gives out from under them. ACL tears cause significant knee swelling and pain.

How is an ACL Injury Diagnosed?

On clinical knee examination, your physiotherapist or sports doctor will look for signs of ACL ligament instability. These special ACL tests place stress on the anterior cruciate ligament and can detect an ACL tear or rupture.

An MRI may also be used to determine if you have an ACL tear. It will also look for signs of any associated injuries in the knee, such as bone bruising or meniscus damage, that regularly occur in combination with an ACL tear.

X-rays are of little clinical value in diagnosing an ACL tear.

How is an ACL Injury Treated?

Many patients with an ACL tear start to feel better within a few days or weeks of an ACL injury. These individuals may feel as though their knee is normal again because their swelling has started to settle. However, this is when your problems with knee instability and giving way may start or worsen.

ACL tears do not necessarily require ACL reconstruction surgery. There are several important factors to consider before deciding to undergo ACL reconstruction surgery.

  • Your age?
  • Do you regularly perform sports or activities that normally require a functional ACL?
  • Do you experience knee instability?
  • What are your plans for the future?

If you don’t participate in a multi-directional sport that requires a patent ACL, and you don’t have an unstable knee, then you may not need ACL surgery.

Physiotherapy & ACL Exercises

Your best way to avoid ACL reconstructive surgery is to undertake a comprehensive ACL-Deficient Knee Rehabilitation Program that involves leg strengthening, proprioception and high-level balance retraining, plus sport-specific agility and functional enhancement. Your sports physiotherapist is an expert in the prescription of ACL tear exercises.

PhysioWorks has developed a specific ACL Deficient Knee Rehabilitation Program to address ACL injuries for the patient who wishes to avoid or delay ACL reconstructive surgery.

Your physiotherapy treatment will aim to:

  • Reduce pain and inflammation.
  • Normalise your joint range of motion.
  • Strengthen your knee: esp Quadriceps (esp VMO) and Hamstrings.
  • Strengthen your lower limb: Calves, Hip and Pelvis muscles.
  • Improve patellofemoral (kneecap) alignment
  • Normalise your muscle lengths
  • Improve your proprioception, agility and balance
  • Improve your technique and function eg walking, running, squatting, hopping and landing.
  • Minimise your chance of re-injury.

We strongly suggest that you discuss your knee injury after a thorough examination from a knee injury clinician such as a sports physiotherapist, sports physician or knee surgeon.

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ACL Surgery

The usual surgery for an ACL tear is called an ACL reconstruction. A repair of the anterior cruciate ligament is rarely a possibility, and thus the ACL is reconstructed using another tendon or ligament to substitute for the torn ligament. There are several options for how to perform ACL surgery.

The most significant choice is the type of graft used to reconstruct the torn ACL. There are also variations in the procedure, such as the new ‘double-bundle’ ACL reconstruction.

You may have heard of a Lars Procedure, which is a new ACL reconstruction procedure. In some, but certainly not most cases, ACL ruptures a stub of the old ligament can be used as a part of the repair procedure, which can hasten your recovery time. Your surgeon will know whether a lars procedure is an option for you or not. There are higher re-rupture risks involved.

Risks of ACL surgery include:

  • infection,
  • persistent instability and pain,
  • knee stiffness, and
  • difficulty returning to your previous level of activity.

The good news is that better than 90% of patients have no complications with ACL surgery.

Post-Surgical ACL Rehabilitation

Post-operative ACL rehabilitation is one of the most important, yet too often neglected, aspects of ACL reconstruction surgery. The most successful and quickest outcomes result from the guidance and supervision of an experienced Sports Physiotherapist.

Your rehabilitation following ACL surgery focuses on restoring full knee motion, strength, power and endurance. You’ll also require balance, proprioception and agility retraining that is individualised towards your specific sporting or functional needs.

Your sports physiotherapist is an expert in this field. We suggest that you contact them for the best advice in your circumstances.

ACL Injuries in Children

ACL reconstruction surgery is the standard treatment for young, active people who sustain an ACL tear. But what happens when you’re young and your bones are still growing?

Should ACL surgery be delayed until the child is older, or should ACL reconstruction be performed before skeletal maturity?

The concern of performing ACL surgery in children is that there is a risk of causing a growth disturbance in growing children. Growth plate problems as a result of ACL surgery could potentially lead to early growth plate closure or alignment deformities.

However, recent research is showing that the risk of growth plate problems is much less than the risk of permanent knee damage if the ACL is not fixed.

Your knee surgeon is the best person to discuss whether ACL reconstruction is advisable or not.

How to Prevent an ACL Injury?

Preventing an ACL tear has been the focus of recent research, especially the prevention of ACL tears in female athletes. Numerous theories have been proposed to explain why people may tear their ACL, and how they can be prevented.

Current investigations have focused on neuromuscular training to prevent ACL tears. Just as we know that ACL reconstruction patients who have extensive post-operative physiotherapy to rebuild their strength, proprioception and agility we do know that similar ACL exercises can help prevent an ACL tear in the first place. For more advice, please consult with your sports physiotherapist.

Return to Sports with an ACL Injury

Athletes often have particular difficulty returning to their sport once they have sustained an ACL injury, even if they are surgically reconstructed.

Researchers have found that your best chance of returning to your sports post-ACL tear is to have undertaken both:

  • ACL reconstruction surgery, and
  • Intensive post-operative physiotherapy rehabilitation.

For more information, please ask the advice of your knee surgeon or sports physiotherapist.

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Knee Pain

Common Causes

Knee Ligament Injuries

  • Knee Ligament Injuries
  • ACL Injury
  • PCL Injury
  • MCL Sprain
  • LCL Sprain
  • Posterolateral Corner Injury
  • Superior Tibiofibular Joint Sprain

Knee Meniscus

  • Meniscus Tear
  • Discoid Meniscus

Knee Tendonitis

  • Patella Tendonitis (Tendinopathy)
  • Pes Anserinus Tendinitis
  • Popliteus Tendinitis

Muscle Injuries

  • Corked Thigh
  • Thigh Strain
  • Hamstring Strain
  • ITB Syndrome
  • Popliteus Syndrome
  • Muscle Strain (Muscle Pain)
  • Cramps
  • DOMS – Delayed Onset Muscle Soreness

Knee Bursitis

  • Bursitis Knee
  • Pes Anserinus Bursitis

Children’s Knee Conditions

  • Osgood Schlatter’s
  • Sinding Larsen Johansson Syndrome

Other Knee-Related Conditions

  • Runner’s Knee
  • Plica Syndrome
  • Fibromyalgia
  • Stress Fracture
  • Overuse Injuries
  • Restless Legs Syndrome
  • Sciatica

Knee Surgery

  • Knee Arthroscopy
  • Knee Replacement

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Common ACL Injury Treatments

  • Early Injury Treatment
  • Avoid the HARM Factors
  • Soft Tissue Injury? What are the Healing Phases?
  • What to do after a Muscle Strain or Ligament Sprain?
  • Acupuncture and Dry Needling
  • Sub-Acute Soft Tissue Injury Treatment
  • Closed Kinetic Chain Exercises
  • Biomechanical Analysis
  • Balance Enhancement Exercises
  • Proprioception & Balance Exercises
  • Agility & Sport-Specific Exercises
  • Medications?
  • Soft Tissue Massage
  • ACL Injury Prevention
  • Brace or Support
  • Dry Needling
  • Electrotherapy & Local Modalities
  • Heat Packs
  • Kinesiology Tape
  • Prehabilitation
  • Strength Exercises
  • Supportive Taping & Strapping
  • TENS Machine
  • Video Analysis
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    FAQs about ACL Injury

  • Common Physiotherapy Treatment Techniques
  • What is Pain?
  • Physiotherapy & Exercise
  • When Should Diagnostic Tests Be Performed?
  • What is the Normal Function of the ACL?
  • What are the Symptoms of an ACL Tear?
  • What should you do if you think you have an ACL Tear?
  • Will You Need an Operation for an ACL Tear?
  • What about the Rehabilitation following ACL Reconstruction?
  • ACL Brace?
  • Can Kinesiology Taping Reduce Your Swelling and Bruising?
  • How Can You Prevent a Future Leg Injury?
  • How Do You Improve Your Balance?
  • How Much Treatment Will You Need?
  • Sports Injury? What to do? When?
  • What are the Common Massage Therapy Techniques?
  • What are the Early Warning Signs of an Injury?
  • What Can You Do To Help Arthritis?
  • What Happens when there is an ACL Injury?
  • What is a TENS Machine?
  • What is Chronic Pain?
  • What is Nerve Pain?
  • What is Sports Physiotherapy?
  • What’s the Benefit of Stretching Exercises?
  • When Can You Return to Sport?
  • Why Kinesiology Tape Helps Reduce Swelling and Bruising Quicker
  • Knee Brace for an ACL Injury

    Many patients will try an ACL brace. The knee brace required will need to stabilise your knee multi-directionally. While trialling an ACL brace is understandable, the success lies in the extent of your ACL instability.

    In other words, highly unstable ACL tears will give out eventually regardless of the brace unless it is custom made and moulded specifically to your knee. These ACL braces are very expensive. However, mild instabilities may allow you to work and undertake non-directional change sport if your wear an ACL brace.

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