ACL Injury: Should I Have Knee Surgery?

Get the facts

Your options

Have ACL surgery followed by a physical rehabilitation (rehab) program.
Try rest, exercise, and physical rehab.

This topic is not meant for children or teenagers. Their bones have not stopped growing, so there are other things to think about. This topic is also not for people who have had ACL surgery or are having revision surgery.

Key points to remember

Surgery may be done for most healthy adults of any age who want to keep up activities that require a strong, stable knee.
Surgery with physical rehabilitation (rehab) is your best chance to have a stable knee and an active lifestyle without more pain, injury, or loss of strength and movement in your knee. But this also depends on how badly your ACL was damaged. You might think about surgery if:
- Your ACL is completely torn or partially torn and unstable.
- You are very active in sports or have a job that requires knee strength and stability (such as construction work).
- You have long-lasting (chronic) ACL deficiency that affects your quality of life.
- You have hurt other parts of your knee, such as the cartilage, meniscus, other knee ligaments, or tendons, or you have broken bones within the knee joint.
- You are willing to complete a long rehab program.
If you're willing to do several months of rehab first, you might want to try it before having surgery.
If you wait too long to fix a torn ACL and you start to get chronic ACL deficiency, the surgeon may not be able to fix all of your joint damage. You may still have pain and swelling. It's important to have surgery before your unstable knee causes other joint problems.
If you are thinking about surgery for ACL injuries, you may want to talk to more than one orthopedic surgeon about your knee injury. You may get different ideas from other doctors about how surgery could be done. Choose the surgeon with whom you feel the most comfortable and who has a good reputation in your community.

FAQs

What are the anterior cruciate ligament (ACL) and an ACL injury?

The anterior cruciate ligament (ACL) is one of four knee ligaments that connect the upper leg bone (femur) with the large lower leg bone (tibia). The ACL keeps your knee stable by:

Keeping your knee from sliding or twisting abnormally when the leg is straight or slightly bent.
Preventing your knee from being stretched or straightened beyond its normal limits.
Supporting the knee ligaments that keep your knee from bending sideways.

An ACL injury is a tear in one of the knee ligaments. It can be:

A small or medium tear of the ligament (partial tear).
A complete tear of the ligament (rupture).
A separation of the ligament from the upper or lower leg bone (avulsion).
A separation of the ligament and part of the bone from the rest of the bone (avulsion fracture).

When any of these things happen, the lower leg bone may slide forward on the upper bone. This may feel like your knee is giving out. An ACL tear may also hurt other bones or joints inside the knee.

What are the risks of an ACL injury?

The risks of an ACL injury depend on:

How bad the injury was.
Whether other parts of your knee also were injured.
Whether you stop or limit activities that require a stable knee.
Whether you complete a rehab program.

If nothing is done, the ACL injury may turn into chronic ACL deficiency. Your knee may become more and more unstable and may give out more often. The abnormal sliding within the knee also can hurt cartilage. It can trap and damage the menisci in the knee and can also lead to early osteoarthritis.

If you can live with a loose knee and avoid doing things that make your knee unstable, you may not get osteoarthritis.
If you keep doing things that make your knee give way and become painful and swollen, you risk future joint problems and disability.

If you wait too long to fix a torn ACL and you start to get chronic ACL deficiency, the surgeon may not be able to fix all of your joint damage. You may still have pain and swelling even after surgery. It's important to have surgery before your unstable knee leads to other joint problems.

How successful is ACL surgery?

After an ACL injury and surgery, most people regain enough strength and range of motion to return to their usual activities. A few people will still have knee pain and instability.

What are the risks of surgery and rehabilitation?

ACL surgery has few risks. Risks and problems that can occur during rehab and recovery include:

Loss of motion in the knee joint.
Grating (or grinding) of the kneecap.
Pain and swelling during daily activities or sports.

Compare your options

Compare


What is usually involved?
What are the benefits?
What are the risks and side effects?

Have ACL surgery Have ACL surgery

You will have spinal or general anesthesia.
Depending on the type of ACL surgery you have, you may go home the same day or spend a few days in the hospital.
You will do physical rehabilitation for several months to a year. Your rehab will continue until your knee is stable and strong.
It takes most people at least 6 months to return to activity after surgery.^{footnote 1}

Surgery with rehabilitation offers the best chance for making your knee stable again.
Most people will regain enough strength and range of motion to return to their usual activities.

A few people will still have knee pain and instability.
All surgery has risks, including bleeding, infection, and nerve damage. Your age and your health also affect your risk.
Other risks of surgery or problems that occur after surgery include:
- Loss of motion to the knee joint.
- Grating (grinding) of the kneecap.
- Pain and swelling during daily activities or sports.

Try rest, exercise, and rehabilitation Try rest, exercise, and rehabilitation

You rest and reduce activity. Your doctor may suggest that you use crutches or a splint.
You use ice for swelling. You wrap your knee with an elastic bandage and keep it propped up on a pillow when you sit or lie down.
You take anti-inflammatory medicines for pain.
You do physical rehabilitation until your knee is stable.

Rest and rehab may be enough to heal your injury or at least make it stable enough so that you can do some activities.
If you decide to have surgery later, you will be in better condition for it because of your rehab program.
You avoid the risks of surgery.

You won't be able to keep doing activities that caused your injury.
You may not regain full use of your knee.
If you wait too long to fix a torn ACL and you start to get chronic ACL deficiency, the surgeon may not be able to fix all of your joint damage.

Personal stories about having surgery for an ACL injury

These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.

My knee is only a little unstable after my ACL injury. My doctor said the decision to have surgery is really up to me. I am going to do some intensive rehab for a few weeks and see how my knee progresses. If I can avoid surgery, I'd like to do that.

Don, age 42

I'm not a competitive athlete, but I am very active and I enjoy running, hiking, and bicycling. My doctor said that my ACL tear wasn't too bad, but I am definitely going to have surgery. I think surgery is my best chance of being able to continue to do all the things I did before I hurt my knee.

Susan, age 38

I'm not a very active person, and so it isn't too important to me that my knee be stable. It only has a small amount of instability right now, so I am not going to have surgery. I feel like the risks of the surgery are more than the risks of not having it, at least for someone like me.

Carmen, age 53

I need a stable knee to do my job well, and I'd also like to avoid getting osteoarthritis early if I can. I'm going to have the reconstruction surgery, even though I know the rehab is long. It's the best chance I have of getting a strong, stable knee.

Peter, age 45

What matters most to you?

Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.

Reasons to choose ACL surgery

Reasons to choose rest, exercise, and physical rehabilitation

I need a healthy knee for work.

My work does not depend on my having a healthy knee.

More important

Equally important

More important

I'm active and involved in sports, so I need a healthy knee.

I'm not that active or involved in sports.

More important

Equally important

More important

I accept the risks of surgery.

I don't want to have surgery for any reason.

More important

Equally important

More important

I can commit to a long rehabilitation program after surgery.

I don't know if I can commit to a long rehab program after surgery.

More important

Equally important

More important

My other important reasons:

More important

Equally important

More important

Where are you leaning now?

Now that you've thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.

ACL surgery

Rest, exercise, and physical rehab

Leaning toward

Undecided

Leaning toward

What else do you need to make your decision?

Check the facts

1, Do rest, exercise, and rehabilitation offer you the best chance for a stable knee?

YesSorry, that's not right. Surgery with physical rehabilitation offers the best chance to have a stable knee and an active lifestyle.
NoYou are right. Surgery with physical rehabilitation offers the best chance to have a stable knee and an active lifestyle.
I'm not sureIt may help to go back and read "Get the Facts." Surgery with physical rehabilitation offers the best chance to have a stable knee and an active lifestyle.

2, If you're not sure about surgery, is it okay to try physical rehab first?

YesYou are right. If you're willing to do several months of rehab first, you might want to try it before surgery.
NoSorry, that's not right. If you're willing to do several months of rehab first, you might want to try it before surgery.
I'm not sureIt may help to go back and read "Get the Facts." If you're willing to do several months of rehab first, you might want to try it before surgery.

3, Can you cause other problems by waiting too long to have surgery?

YesYou are right. If you wait too long to fix a torn ACL and you start to get chronic ACL deficiency, the surgeon may not be able to fix all of your joint damage.
NoSorry, that's not right. If you wait too long to fix a torn ACL and you start to get chronic ACL deficiency, the surgeon may not be able to fix all of your joint damage.
I'm not sureIt may help to go back and read "Get the Facts." If you wait too long to fix a torn ACL and you start to get chronic ACL deficiency, the surgeon may not be able to fix all of your joint damage.

Decide what's next

1,Do you understand the options available to you?

Yes
No

2,Are you clear about which benefits and side effects matter most to you?

Yes
No

3,Do you have enough support and advice from others to make a choice?

Yes
No

Certainty

1.
How sure do you feel right now about your decision?

Not sure at all

Somewhat sure

Very sure

2, Check what you need to do before you make this decision.

3.
Use the following space to list questions, concerns, and next steps.

Your Summary

Here's a record of your answers. You can use it to talk with your doctor or loved ones about your decision.

Author	Healthwise Staff
Primary Medical Reviewer	William H. Blahd Jr. MD, FACEP - Emergency Medicine
Primary Medical Reviewer	Brian D. O'Brien MD - Internal Medicine
Primary Medical Reviewer	E. Gregory Thompson MD - Internal Medicine
Primary Medical Reviewer	Adam Husney MD - Family Medicine
Primary Medical Reviewer	Kathleen Romito MD - Family Medicine
Primary Medical Reviewer	Freddie H. Fu MD - Orthopedic Surgery

	Have ACL surgery	Try rest, exercise, and rehabilitation
What is usually involved?	You will have spinal or general anesthesia. Depending on the type of ACL surgery you have, you may go home the same day or spend a few days in the hospital. You will do physical rehabilitation for several months to a year. Your rehab will continue until your knee is stable and strong. It takes most people at least 6 months to return to activity after surgery.¹	You rest and reduce activity. Your doctor may suggest that you use crutches or a splint. You use ice for swelling. You wrap your knee with an elastic bandage and keep it propped up on a pillow when you sit or lie down. You take anti-inflammatory medicines for pain. You do physical rehabilitation until your knee is stable.
What are the benefits?	Surgery with rehabilitation offers the best chance for making your knee stable again. Most people will regain enough strength and range of motion to return to their usual activities.	Rest and rehab may be enough to heal your injury or at least make it stable enough so that you can do some activities. If you decide to have surgery later, you will be in better condition for it because of your rehab program. You avoid the risks of surgery.
What are the risks and side effects?	A few people will still have knee pain and instability. All surgery has risks, including bleeding, infection, and nerve damage. Your age and your health also affect your risk. Other risks of surgery or problems that occur after surgery include: Loss of motion to the knee joint. Grating (grinding) of the kneecap. Pain and swelling during daily activities or sports.	You won't be able to keep doing activities that caused your injury. You may not regain full use of your knee. If you wait too long to fix a torn ACL and you start to get chronic ACL deficiency, the surgeon may not be able to fix all of your joint damage.

By	Healthwise Staff
Primary Medical Reviewer	William H. Blahd Jr. MD, FACEP - Emergency Medicine
Primary Medical Reviewer	Brian D. O'Brien MD - Internal Medicine
Primary Medical Reviewer	E. Gregory Thompson MD - Internal Medicine
Primary Medical Reviewer	Adam Husney MD - Family Medicine
Primary Medical Reviewer	Kathleen Romito MD - Family Medicine
Primary Medical Reviewer	Freddie H. Fu MD - Orthopedic Surgery

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ACL Injury: Should I Have Knee Surgery?