What is an anterior cruciate ligament (ACL) injury?
An anterior cruciate ligament, or ACL, injury is a tear in one of the
knee
ligaments that joins the upper leg bone with the lower
leg bone. The ACL keeps the knee stable. See a picture of the
knee and the ACL.
Injuries range from mild, such as a small tear, to
severe, such as when the ligament tears completely or when the ligament and
part of the bone separate from the rest of the bone.
Without
treatment, the injured ACL is less able to control knee movement, and the bones
are more likely to rub against each other. This is called chronic ACL
deficiency. The abnormal bone movement can also damage the tissue (cartilage) that covers
the ends of the bones and can trap and tear the pads (menisci) that
cushion the knee joints. This damage can lead to
osteoarthritis.
Sometimes other knee
ligaments or parts of the knee are also injured. This includes cartilage such
as the menisci, or bones in the knee joint, which can be
broken.
What causes an ACL injury?
Your ACL can be injured
if your knee joint is bent backward, twisted, or bent side to side. The chance
of injury is higher if more than one of these movements occurs at the same
time. Contact (being hit by another person or object) also can cause an ACL
injury.
An ACL injury often occurs during sports. The injury can
happen when your foot is firmly planted on the ground and a sudden force hits
your knee while your leg is straight or slightly bent. This can happen when you
are changing direction rapidly, slowing down when running, or landing from a
jump. This type of injury is common in soccer, skiing, football, and other
sports with lots of stop-and-go movements, jumping, or weaving. Falling off a
ladder or missing a step on a staircase are other likely causes. Like any other
body part, the ACL becomes weaker with age. So a tear happens more easily in
people older than age 40.
What are the symptoms?
Symptoms of an acute ACL
injury include:
Feeling or hearing a pop in the knee at the
time of injury.
Pain on the outside and back of the
knee.
The knee swelling within the first few hours of the injury.
This may be a sign of bleeding inside the knee joint. Swelling that occurs
suddenly is usually a sign of a serious knee injury.
Limited knee
movement because of pain or swelling or both.
The knee feeling
unstable, buckling, or giving out.
After an acute injury, you will probably have to stop
whatever you are doing because of the pain, but you may be able to walk.
The main symptom of chronic ACL deficiency is the knee buckling or
giving out, sometimes with pain and swelling. This can happen when an ACL
injury is not treated.
How is an ACL injury diagnosed?
Your doctor can
tell whether you have an ACL injury by asking questions about your past health
and examining your knee. The doctor may ask: How did you injure your knee? Have
you had any other knee injuries? Your doctor will check for stability,
movement, and tenderness in both the injured and uninjured knee.
You may need
X-rays, which can show damage to the knee bones. Or
you may need other imaging tests, such as an
MRI. An MRI can show damage to ligaments,
tendons, muscles, or knee cartilage.
Arthroscopy may also be done. During arthroscopy, your
doctor inserts surgical tools through one or more small cuts (incisions) in the
knee to look at the inside of the knee.
How is it treated?
Start first aid right away.
These first-aid tips will reduce swelling and pain. Use the RICE method. The
letters stand for Rest the knee, put Ice on it, use an elastic bandage to give gentle
Compression to the knee, and Elevate the leg by propping it up above the level of your
heart. And it's also important to move your leg as little as possible. Take
over-the-counter pain medicine.
You may need to walk with
crutches and use a knee immobilizer to keep your knee still for the first few
days after the injury.
Your knee will need to be checked by your
doctor. It's important to get treatment. If you don't, the injury may become a
long-lasting problem. There are two ways to treat the injury:
Exercises and training, also called rehab. It
takes several months of rehab for your knee to get better.
Surgery. You and your doctor can decide if rehab is enough or if surgery is
right for you.
If you have surgery, you will also have several months of
rehab afterward.
Your treatment will depend on how much of the
ACL is torn, whether other parts of the knee are injured, how active you are,
your age, your overall health, and how long ago the injury occurred.
There are three main treatment goals:
Make the knee stable if it is unsteady, or at
least make it stable enough to do your daily activities.
Make your
knee strong enough to do all the activities you used to do.
Reduce
the chance that your knee will be damaged more.
How can you prevent ACL injuries?
The best way to
prevent ACL injuries is to stretch and strengthen the leg muscles, especially
the front and back muscles of the thigh (quadriceps and hamstrings).
Other things you can do that may help prevent ACL injuries
include:
Avoid wearing shoes with cleats in contact
sports.
Avoid wearing high-heeled shoes.
Avoid sports
that involve lots of twisting and contact.
Frequently Asked Questions
Learning about anterior cruciate ligament (ACL) injuries:
Typical situations that can lead to ACL injuries include:
Changing direction quickly or cutting around an
obstacle or another player with one foot solidly planted on the ground (as can
happen in
sports that put high demand on the ACL such as
basketball, football, soccer, hockey, and gymnastics).
Landing
after a jump with a sudden slowing down, especially if the leg is straight
(such as in basketball).
Falling off a ladder, stepping off a curb,
jumping from a moderate or extreme height, stepping into a hole, or missing a
step when walking down a staircase. Injuries from these situations tend to be
caused by stopping suddenly, with the leg straight.
Inactive people and some older adults who have weak leg
muscles may injure their knees during normal daily activities. But they usually
injure bones, not ligaments.
When contact causes an ACL injury, it
can be from playing a sport, from a sudden and severe accident, or from less
obvious contact injuries. In football, receiving a clipping contact injury-in
which the bent knee is struck from the outside-can cause an ACL injury.
Clipping often damages several knee structures at the same time, including the
ACL, the medial collateral ligament (MCL), and the pads in the
knee (menisci) that protect and cushion the joint surface
and bone ends. Clipping injures the medial meniscus more often than the lateral
meniscus.
An ACL injury may develop into long-lasting and
recurrent (chronic)
ACL deficiency that leads to an unstable knee-the knee buckles or gives out,
sometimes with pain and swelling. This can occur if your ACL has not been
treated or has been treated unsuccessfully, or if you had an ACL injury in the
past and did not know it.
Feeling or hearing a "pop" in the knee at the
time of injury.
Sudden instability in the knee (the knee feels
wobbly, buckles or gives out) after a jump or change in direction or after a
direct blow to the side of the knee.
Pain on the outside and back
of the knee.
Knee swelling within the first few hours of the
injury. This may be a sign of bleeding inside the joint (hemarthrosis). Swelling that occurs suddenly is
usually a sign of a serious knee injury.
Limited knee movement
because of swelling and/or pain.
After an acute injury, you will almost always have to stop
the activity you are engaged in but may be able to walk.
The main
symptom of chronic (long-lasting and recurrent)
ACL deficiency is an unstable knee joint. The knee buckles or gives out,
sometimes with pain and swelling. This happens more often over time. But not
everyone with an ACL injury develops a chronic ACL deficiency.
Other conditions with symptoms similar to ACL knee pain include injuries
to other knee structures, such as:
An injury to the cartilage lining the knee
joint.
An injury to the knee cushions (menisci). About
70% of people with an ACL injury also have a
meniscus tear.1
An injury to the knee ligaments that connect the
upper leg bone to the lower leg bone along the inner side of the knee joint
(medial collateral ligament) and the outer side of the knee joint (lateral collateral ligament).
A break (fracture) in the bones of the
knee joint.
If you have a sudden (acute)
anterior cruciate ligament (ACL) injury, you generally
know when it happens. You may feel or hear a pop and the knee may give out,
causing you to fall. The knee swells and often is too painful or unstable to
continue any activity.
An ACL injury can cause small or medium
tears of the ligament, a complete tear of the ligament (rupture), a separation
of the ligament from the upper or lower leg bone (avulsion), or a separation of
the ligament and part of the bone from the rest of the bone (avulsion
fracture). When any of these occur, the lower leg bone moves abnormally forward
on the upper bone, with a sense of the knee giving out or buckling.
When the ACL ligament tears, the blood vessels around the ligament tear
and blood fills the knee joint, causing swelling. When you see a doctor, he or
she may not be able to examine the knee thoroughly because of the
swelling.
Other parts of the knee can be injured at the same time.
These may include one of the pads that act as cushions between the two leg
bones (menisci), another knee ligament (medial collateral ligament or
lateral collateral ligament), or the dense tissue that covers the ends of bones
(cartilage). The bones of the knee joint may also be
broken (fractured).
Diagnosis may not be done at the time of
injury. Sometimes people think the injury is not serious, especially if the
knee gets better in a few days. In this case, or if the diagnosis is missed
during the initial examination, the injury may develop into a long-lasting and
recurrent (chronic)
ACL deficiency, in which the knee moves abnormally and gives way
occasionally. This can potentially cause progressive damage to the joint,
including
osteoarthritis. But not everyone with an ACL injury
develops a chronic ACL deficiency.
The course of an ACL injury
depends on:
The condition of the ACL before this injury,
including prior injuries, partial tears, ACL deficiency, and degenerative
changes due to age.
The general condition and health of all of your
knee structures prior to this injury.
The amount of damage or
injury to the ACL. Injuries to the ACL are usually grouped into
grade I, II, or III sprains (tears) according to the
amount of damage.
Additional injuries to the knee joint, such as to
the
cartilage or
menisci, or to bones in the knee.
Your
age, how active you are, and how committed you are to treatment and
rehabilitation.
The time of diagnosis. If the ACL diagnosis is not
made soon after the injury, the knee may be further damaged with use.
People with minor ACL injuries usually begin treatment with
a physical rehabilitation program. Rehabilitation exercises build strength and
flexibility in the muscles on the front of the thigh (quadriceps) and
strengthen and tighten the muscles in the back of the thigh (hamstrings). You
may use crutches for a short time. Although knee braces may be used to
stabilize the knee immediately after injury, they are not usually used
long-term. Most people return to their normal activities after a few weeks of
rehabilitation.
More serious ACL injuries may require several
months of rehabilitation or surgery followed by several months of
rehabilitation to regain your knee strength, knee stability, and range of
motion. You may use crutches or special knee braces, and it may take several
months to a year until you can return to your previous level of activity. The
rehabilitation program is intensive-many people think of it as having a second
job.
Not all ACL injuries require surgery, but whether you have
surgery or not, you need to start strengthening your knee and regaining motion
soon after you injure it. This prepares you for your rehabilitation program if
you choose not to have surgery and also helps prepare the knee for surgery if
you choose to have it.
Playing
sports that involve sudden changes in direction or
cutting around other players or obstacles, such as skiing, football, soccer,
basketball, baseball, and tennis.
Making accidental movements that
may twist your knee, such as falling off a ladder, jumping from an extreme
height, stepping into a hole, or missing a step on a
staircase.
Losing muscle tone in legs (from aging or
inactivity).
Having unbalanced leg muscle strength, such as if the
muscles in the front of your thigh (quadriceps) are stronger than the muscles
at the back of your thigh (hamstrings).
Previous ACL injuries,
especially if your knee sometimes gives out or buckles (chronic ACL deficiency).
Women have more ACL injuries than men. In sports, women
injure their ACL up to 8 times as often as men. There are
several theories for the increased incidence in women
athletes, including differences in men's and women's bodies and how they use
muscles, and training that does not help make up for these differences.2, 3
When To Call a Doctor
Call your doctor immediately if you have an injury to your knee and:
You have severe pain in your
knee.
Your knee appears to be deformed.
You have signs
of damage to the nerves or blood vessels, such as numbness, tingling, a
"pins-and-needles" sensation below the injury, an inability to move your leg
below the injury, pale or bluish skin, or your leg feels cold.
Call your doctor today if:
Your knee begins to swell within 2 hours of the
injury.
You hear or feel a pop in your knee during an
injury.
Before your appointment, do not put weight on the injured
knee. Use crutches if necessary.
Apply ice and wrap your knee in an elastic bandage or
neoprene (synthetic rubber) sleeve. Rest and elevate the knee. Take a
nonprescription anti-inflammatory drug to reduce
swelling. For more information on first aid steps, see the Home Treatment
section of this topic.
Watchful Waiting
Watchful waiting is a period of time during
which you and your doctor observe your symptoms or condition without using
medical treatment. Watchful waiting is not appropriate if knee pain is severe,
your knee is deformed or swells immediately after an injury, or you are unable
to bear any weight, either because of pain or instability.
Serious
knee injuries need to be checked for possible broken bones as well as
ligament or
cartilage damage. Whenever immediate swelling follows
an injury, there also may be torn blood vessels or damaged nerves in the knee.
Your doctor will check your knee to make sure the blood supply to your leg is
normal and the nerves are intact.
If you have occasional pain in
your knee or your knee sometimes gives way or buckles, have your doctor check
it. If you have damaged your ACL, it is important to get treatment so that your
knee is appropriately managed, which may reduce the chance that you will get
osteoarthritis in your knee.
Taking your
medical history. You will be asked how you injured
your knee, about your symptoms at the time of injury, whether you have had any
other knee injuries, and general questions about your health.
Checking your knees for stability, strength, range of
movement, swelling, and tenderness. Tests for stability include a Lachman test
and a pivot shift test. The Lachman test compares the degree of looseness
(laxity) in your knees.
Looking at an
X-ray, which is usually done for any knee injury.
Although an ACL injury cannot be directly diagnosed by an X-ray, it can
determine whether a bone is broken, any bone fragments are in the knee, the ACL
is torn from the bone (avulsion), or blood is present in the knee
(effusion).
If you see your doctor soon after your injury, the pain
and the degree of swelling and muscle tenseness may make it difficult for your
doctor to accurately diagnose the condition.
Other tests that may
help determine how badly the knee is injured include:
If your knee is red, hot, or very swollen, a
knee joint aspiration (arthrocentesis) may be done,
which involves removing fluid from the knee joint with a syringe (needle). This
is done to:
Help relieve pain and pressure, which may make
the physical exam easier and make you more comfortable.
Check joint
fluid for possible infection or inflammation.
Identify blood, which
may indicate a tear.
Identify drops of fat, which may indicate a
broken bone.
Fluid removed from the knee joint may be tested to identify
blood and fatty droplets from a hidden
fracture. Local anesthetic may be injected to reduce
pain and make the knee easier to examine. If the ACL is torn, fluid drained
from the knee may contain a lot of blood.
Arthrometric testing of
the knee may also be done. In this test, your doctor uses an instrument to
measure the looseness of your knee. This test is especially useful in people
whose pain or physical size makes a physical exam difficult. An arthrometer has
two sensor pads and a pressure handle that allows your doctor to put force on
the knee. The instrument is strapped to your lower leg so that the sensor pads
are placed on the knee cap and the small bump just below it (tibial tubercle).
Your doctor then measures pressure by pulling or pushing on the pressure
handle.
Arthroscopy is another procedure used
in the diagnosis of an ACL injury and is also usually used as a method of
surgery. Arthroscopy involves inserting instruments through one or more small
incisions in the knee, allowing your doctor to examine the structures inside
the knee joint, including the ACL.
Before arthroscopy, you and
your doctor will decide what will be done if certain conditions are found. For
example, you may decide in advance that if a complete tear of the ACL is found,
it will be reconstructed during the arthroscopy. Or, if a more severe condition
is found, you and your doctor may agree to discuss the condition rather than
proceeding with surgery at that time.
Treatment Overview
There are three main treatment
goals. The first goal is to stabilize the knee if it is unstable-or at least
stabilize it enough to suit your lifestyle. The second goal is to return your
knee to normal or almost normal functioning. The third goal is to reduce the
likelihood of further damage to the knee. Treating
anterior cruciate ligament (ACL) injuries may also
help to reduce pain, prevent
osteoarthritis, and prevent loss of strength and
decreased movement in the knee.
Initial treatment of an acute ACL
injury consists of using first aid steps to stabilize your knee and reduce
swelling and pain.
Later treatment may include several months of
rehabilitation or surgery with rehabilitation. Not all ACL tears require
surgery. Further treatment is nearly always a decision you and your doctor make
between rehabilitation only and surgery plus rehabilitation.
Acute (sudden) ACL injuries
If you know you have
injured your ACL, initial treatment consists
of:
Using crutches and/or immobilizing splints in the
first few days after an injury. If crutches or splints are used for too long,
the muscles will become weaker from too little activity, and movement of the
knee will become stiff and restricted.
Strength and motion
exercises to help prepare you for treatment. For more information, see:
When the
injury occurred and how stable your knee is.
Whether other parts of
the knee are injured. If other parts of your knee are injured, it will be
harder for the strong parts of your knee to compensate and protect the injured
parts.
Preexisting conditions of the knee, such as prior injuries
that resulted in long-term (chronic)
ACL deficiency, or
osteoarthritis.
How active you
are.
Your age and overall health status.
Your
willingness and ability to complete a long and rigorous rehabilitation.
ACL surgery to reconstruct the ACL or to reconstruct
the ACL and repair injuries that occurred at the same time, such as a
meniscus tear. Most ACL surgery is done by making
small incisions in the knee and inserting instruments for surgery through these
incisions (arthroscopic surgery). Open surgery (cutting a larger
incision in the knee) is sometimes required. Physical rehabilitation always
follows surgery.
Recovery from an ACL injury varies with each individual.
Your treatment should continue until your knee is stable and strong, not for a
certain length of time.
Treatment in children and teens
Anterior cruciate ligament (ACL) injuries in children
and teens are less common than in adults, but they do occur, especially in
teens. An untreated or unsuccessfully treated ACL injury in children or teens
may result in future knee problems. The knee may become more and more unstable
and, over time,
osteoarthritis may develop.
A child with
an ACL injury can sometimes be treated without surgery in order to avoid damage
to the child's still-developing bones. Nonsurgical treatment includes
rehabilitation exercises, wearing a brace, and avoiding activities that require
jumping or twisting. Nonsurgical treatment is not always successful. A child's
level of activity is a strong factor in how successful treatment is. Studies
suggest that the more active a child is, the less likely nonsurgical treatment
will be successful and the more likely surgery will be needed in the
future.4
An avulsion fracture (a
separation of the ligament and a piece of the bone from the rest of the bone)
is more common in young children. It can often be treated with a cast but
sometimes needs surgery.
Surgery in a child might be necessary to
prevent injury to other structures within the knee, such as the
menisci. You may consider surgery if the child's knee
is very unstable doing simple daily activities, if the knee's instability
cannot be controlled with nonsurgical methods, if the child has both an ACL
injury and a
meniscus tear, or if the child is a serious athlete in
sports that require running, jumping, and decelerating. Postsurgery rest and a
sustained rehabilitation program are extremely important.5
The main risks of surgery in a child whose bones
are still growing is slowed growth (physeal arrest), which may result in one
leg being longer than another. Other risks include the thigh bone pointing
inward (distal femoral valgus or angular limb deformity). The closer a child or
teen is to skeletal maturity, the lower the risk of these conditions.
What To Think About
Things that you should consider
about treatment options include:
Your goals for recovery. How stable and
strong do you want your knee to be? What activities do you hope to return
to?
How motivated you are to complete a long and rigorous
rehabilitation program. Are you able to complete a rehabilitation
program?
Depending on how severe your injury is, surgery with
rehabilitation may offer the best chance of making your knee stable again and
of continuing an active lifestyle without further pain, injury, or loss of
strength and movement in your knee. Age is not a factor, although your overall
health may be. Surgery may be done for adults at any age who want to continue
activities that require a strong, stable knee.
If your initial
injury resulted in an unstable knee that occasionally gives out (chronic ACL deficiency) and you continue to participate in activities that
require a stable knee and don't have surgery, you may injure your knee again.
You will need to follow a rehabilitation program whether or not
you have surgery. If you do not complete a rehabilitation program, even with
surgery you may not regain full stability and function in your knee.
You may choose to start a rehabilitation program to avoid or delay knee
surgery by strengthening and developing flexibility in the muscles that support
the knee (hamstrings and quadriceps). If you eventually need surgery, you will
be much better conditioned for it and for the rehabilitation that follows.
An avulsion fracture (a separation of the ligament and a piece of
the bone from the rest of the bone) is rare in adults. But when this fracture
occurs in adults, surgery may be needed to reattach the bones.
Prevention
The best way to prevent
anterior cruciate ligament (ACL) injuries is to
stretch and strengthen the leg muscles, especially the front and back muscles
of the thigh (quadriceps and hamstrings).
Other precautions that
may help prevent ACL injuries include:
Avoid wearing shoes with cleats in contact
sports.
Avoid wearing high-heeled shoes.
Avoid sports
that involve lots of twisting and contact.
If you have already had an ACL injury, you can avoid
another ACL injury by:
Strengthening the injured knee through
rehabilitation exercises.
Changing your sports techniques to avoid
motions that might stress the injured knee.
Changing your lifestyle
to avoid
sports that have a high risk of injuring your knee
further, such as skiing, football, soccer, or basketball.
Wearing a
knee brace during high-risk activities. But braces should be used only if
rehabilitation is also being done. Wearing a brace alone may be of little
benefit and may give you a false sense of security.
Programs to prevent ACL injuries are available. These
programs generally emphasize injury awareness, avoidance techniques, and
stretching, strengthening, and jumping exercises to help reduce ACL
injuries.
Tips to prevent ACL injuries include practicing
landing after jumps with the knees bent and crouching when pivoting and
turning.
Rest and reduce your activity level.
Use crutches if it hurts to put weight on your knee, until you can see your
doctor. Crutches can be rented from most pharmacies. When you call for an
appointment, tell your doctor that you are using crutches. Crutches should not
be used for long because a lack of activity can cause muscle tissue to waste
away and result in restricted movement of the knee.
Ice your knee. To avoid a freeze-burn, do not put the ice directly on your skin.
Put a cloth or towel between the ice and your knee.
Elevate your
knee while applying ice or any time you are sitting or lying
down.
Wrap your knee with an elastic bandage or neoprene sleeve
(available at a pharmacy). This may help ease pain during movement and reduce
fluid inside the knee. Don't wrap your knee too tightly, as this may cause
swelling below the bandage. Loosen the bandage if it is too tight. Signs of an
overly tight bandage include numbness, tingling, increased pain, and coolness
in the foot.
After diagnosis of an ACL injury, your doctor may suggest
exercises that help strengthen your leg and increase your range of motion. They
may be the start of your nonsurgical treatment program or be used to help
prepare your knee for surgery. For more information, see:
Medicine is used for an
anterior cruciate ligament (ACL) injury to relieve or
reduce pain. It also may be used for long-term (chronic)
ACL deficiency and during the rehabilitation period. Nonprescription pain
medicines such as acetaminophen (Tylenol, for example) or
nonsteroidal anti-inflammatory drugs (NSAIDs), such as
ibuprofen and naproxen, are commonly used.
NSAIDs may cause
stomach upset and should be taken with food and a glass of water. They can have
side effects and should not be taken with certain other medicines. Let your
doctor know what other medicines you are taking. Do not give aspirin to anyone younger than 20 because of the risk of
Reye's syndrome.
Surgery
Most surgery for
anterior cruciate ligament (ACL) injuries involves
replacing the ACL with tissue called a
graft. Usually an autograft (tendon tissue
taken from another part of the body) is used. Repair is also done when the ACL
has been torn from the upper or lower leg bone (avulsion). This type of injury
is uncommon. In the case of an avulsion fracture, the bone fragment connected
to the ACL is reattached to the bone.
Most ACL surgery is done by
making small incisions in the knee and inserting instruments for surgery
through these incisions (arthroscopic surgery). Open surgery
(cutting a large incision in the knee) is sometimes required.
The
goals of surgical treatment for anterior cruciate ligament (ACL) injuries are
to:
Restore normal or almost normal stability in
the knee.
Restore the level of function you had before the knee
injury.
Limit loss of function in the knee.
Prevent
injury or degeneration to other knee structures.
Surgical techniques and rehabilitation programs used today
generally are successful. Between 80% and 90% of people who have ACL surgery
have favorable results, with reduced pain, good knee function and stability,
and a return to normal levels of activity.6
Unfortunately, 3% to 10% of people who have ACL surgery still have knee pain
and instability.7 Athletes and those who participate
in sports generally can return to their sports within months, depending on how
intense and sports-focused the rehabilitation was.
Not all ACL
tears require surgery. You and your doctor will decide whether rehabilitation
only or surgery plus rehabilitation is right for you. For more information,
see:
Before ACL surgery, strength and motion exercises are often
done to help condition the knee for surgery and the subsequent rehabilitation
program. Surgery is followed by a short period of performing home exercises,
increased activity, and the use of crutches for walking. An intensive
rehabilitation program to strengthen the knee then begins. The rehabilitation
program often lasts up to a year. For more information, see:
Surgery in a child might be necessary to prevent injury to
other structures within the knee, such as the
menisci. You may consider surgery if the child's knee
is very unstable doing simple daily activities, if the knee's instability
cannot be controlled with nonsurgical methods, if the child has both an ACL
injury and a
meniscus tear, or if the child is a serious athlete in
sports that require running, jumping, and decelerating. Postsurgery rest and a
sustained rehabilitation program are extremely important.5
The main risks of surgery in a child whose bones
are still growing is slowed growth (physeal arrest), which may result in one
leg being longer than another. Other risks include the thigh bone pointing
inward (distal femoral valgus or angular limb deformity). The risks of these
conditions is lower the closer a child or teen is to skeletal maturity.
Depending on how severe your injury is,
surgery followed by a rehabilitation program may offer the best chance of
making your knee stable again and of your continuing an active lifestyle
without further pain, injury, or loss of strength and movement in your knee.
Without surgery, it is more likely that loss of knee function, osteoarthritis,
and other knee problems will develop later.
In adults, age is not a
factor in surgery, although your overall health may be. Surgery may not be the
ideal treatment for people with medical conditions that make surgery a greater
risk. These people may choose nonsurgical treatment and try to change their
activity level to protect their knee from further injury.
Surgery
is sometimes delayed until the swelling goes down, you have full range of
motion in your knee again, and you can strongly contract (flex) the muscles in
the front of your thigh (quadriceps). You and your doctor decide on the timing
of your surgery.
Whether you have surgery soon after the injury or
weeks later does not seem to affect recovery significantly.3
You will need to follow a rehabilitation program
whether or not you have surgery. If you do not complete a rehabilitation
program, even with surgery you may not regain full stability and function in
your knee.
If your initial injury resulted in an unstable knee that
sometimes gives out (chronic ACL deficiency) and you continue participating
in activities that require a stable knee and don't have surgery, you may injure
your knee again.
Possible complications of arthroscopic knee
surgery include a loss of motion (most common), pain that does not go away,
fluid in the knee joint (postoperative effusion), damage to the knee cartilage
from the arthroscope scraping against it, and infection. Other risks include a
blood clot in the leg, and in extremely rare circumstances, this blood clot can
migrate to the lungs and block blood flow out of the lungs (pulmonary embolism).
You may choose to have surgery if you:
Have completely torn your ACL or have a
partial tear and your knee is very unstable.
Have gone through a
rehabilitation program and your knee is still unstable.
Are very
active in sports or have a job that requires knee strength and stability (such
as construction work), and you want your knee to be as strong and stable as it
was before your injury.
Are willing to complete a long and
rigorous rehabilitation program.
Have a minor tear in your ACL (a tear that
can heal with rest and rehabilitation).
Are not very active in
sports or your work does not require a stable knee.
Are willing to
stop doing activities that require a stable knee or stop doing them at the same
level of intensity. You may choose to substitute other activities that don't
require a stable knee, such as cycling or swimming.
Can complete a
rehabilitation program that stabilizes your knee and strengthens your leg
muscles to reduce the chances that you will injure your knee again and are
willing to live with a small amount of knee instability.
Do not
feel motivated to complete the long and rigorous rehabilitation program
necessary after surgery.
Protect the
ACL and your knee joint from further injury.
Allow you to return to
most activities that you did before the injury. If rehabilitation is done
without surgery, recurrent instability may be a problem during some
movements.
You may choose to treat an ACL injury with rehabilitation
alone. If you have surgery, rehabilitation will also be part of your
treatment.
Physical rehabilitation to
treat ACL injuries, both with and without surgery, can be a long and rigorous
program.
Physical rehabilitation done before surgery helps your
recovery after surgery.
Some people who initially choose not to
have surgery eventually need to have it.
People who choose not to
have ACL surgery may be less likely to return to competitive sports than those
who choose to have it.
Other Places To Get Help
Organizations
American Academy of Orthopaedic Surgeons
(AAOS)
6300 North River Road
Rosemont, IL 60018-4262
Phone:
1-800-346-AAOS (1-800-346-2267) (847) 823-7186
Fax:
(847) 823-8125
E-mail:
pemr@aaos.org
Web Address:
www.aaos.org
The American Academy of Orthopaedic Surgeons (AAOS) provides
information and education to raise the public's awareness of musculoskeletal
conditions, with an emphasis on preventive measures. The AAOS Web site contains
information on orthopedic conditions and treatments, injury prevention, and
wellness and exercise.
American College of Sports Medicine (ACSM)
P.O. Box 1440
Indianapolis, IN 46206-1440
Phone:
(317) 637-9200
Fax:
(317) 634-7817
Web Address:
www.acsm.org
The American College of Sports Medicine (ACSM) provides general
information and publications about exercise and sports medicine.
Shea MA, et al. (2003). Knee pain, swelling, and
instability. Physician and Sportsmedicine, 31(9):
31-33.
Seroyer S, West R (2007). Anterior cruciate ligament
section of Injuries specific to the female athlete. In PJ McMahon, ed.,
Current Diagnosis and Treatment in Sports Medicine, pp.
259-260. New York: McGraw-Hill.
D'Amato MJ, Rach BR Jr (2003). Anterior cruciate
ligament reconstruction in the adult section of Anterior cruciate ligament
injuries. In JC DeLee, D Drez Jr, eds., Orthopaedic Sports Medicine, 2nd ed., vol. 2, pp. 2012-2067. Philadelphia:
Saunders.
Shea KG, et al. (2003). Anterior cruciate ligament
injury in paediatric and adolescent patients. A review of basic science and
clinical research. Sports Medicine, 33(6):
455-471.
Silbey MB, Fu FH (2001). Anterior cruciate ligament.
In FH Fu, DA Stone, eds., Sports Injuries: Mechanisms, Prevention, Treatment, 2nd ed., pp. 1115-1121. Philadelphia:
Lippincott Williams and Wilkins.
Fu FH, et al. (2000). Current trends in anterior cruciate ligament reconstruction. American Journal of Sports Medicine, 28(1): 123-130.
Noyes FJ, Barber-Westin SD (2001). Revision anterior cruciate ligament reconstruction: Report of 11-year experience and results in 114 consecutive patients. AAOS Instructional Course Lectures, 50: 451-461.
Other Works Consulted
Grant JA, et al. (2003). ACL reconstruction with
autografts. Physician and Sportsmedicine, 31(4): 27-32,
40.
Grudziak JS, Musahl V (2007). Anterior cruciate
ligament tear section of The youth athlete. In PJ McMahon, ed., Current Diagnosis and Treatment in Sports Medicine, pp.
213-220. New York: McGraw-Hill.
Miller SL, et al. (2002). Graft selection in anterior
ligament reconstruction. Orthopedic Clinics of North America, 33(4): 675-683.
Trees AH, et al. (2006). Exercise for treating
isolated anterior cruciate ligament injuries in adults. Cochrane Database of Systematic Reviews (3). Oxford: Update
Software.
This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.
Shea MA, et al. (2003). Knee pain, swelling, and
instability. Physician and Sportsmedicine, 31(9):
31-33.
Seroyer S, West R (2007). Anterior cruciate ligament
section of Injuries specific to the female athlete. In PJ McMahon, ed.,
Current Diagnosis and Treatment in Sports Medicine, pp.
259-260. New York: McGraw-Hill.
D'Amato MJ, Rach BR Jr (2003). Anterior cruciate
ligament reconstruction in the adult section of Anterior cruciate ligament
injuries. In JC DeLee, D Drez Jr, eds., Orthopaedic Sports Medicine, 2nd ed., vol. 2, pp. 2012-2067. Philadelphia:
Saunders.
Shea KG, et al. (2003). Anterior cruciate ligament
injury in paediatric and adolescent patients. A review of basic science and
clinical research. Sports Medicine, 33(6):
455-471.
Silbey MB, Fu FH (2001). Anterior cruciate ligament.
In FH Fu, DA Stone, eds., Sports Injuries: Mechanisms, Prevention, Treatment, 2nd ed., pp. 1115-1121. Philadelphia:
Lippincott Williams and Wilkins.
Fu FH, et al. (2000). Current trends in anterior cruciate ligament reconstruction. American Journal of Sports Medicine, 28(1): 123-130.
Noyes FJ, Barber-Westin SD (2001). Revision anterior cruciate ligament reconstruction: Report of 11-year experience and results in 114 consecutive patients. AAOS Instructional Course Lectures, 50: 451-461.
