by EBSCO Medical Review Board


ACL surgery is done to reconstruct the ACL in the knee after it is torn.

Anterior Cruciate Ligament Injury
ACL injury
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Reasons for Procedure

This surgery is done in people who have not been helped by other methods, such as physical therapy and bracing. It is also done when a person has loss of function and problems doing activities.

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

  • Excess bleeding
  • Problems from anesthesia, such as wheezing or sore throat
  • Infection
  • Blood clots
  • Surgery does not ease symptoms
  • The knee becomes unstable
  • Numbness or stiffness in the knee

Things that may raise the risk of problems are:

  • Smoking
  • Drinking
  • Chronic diseases, such as diabetes or obesity

What to Expect

Prior to Procedure

The surgical team may meet with you to talk about:

  • Anesthesia options
  • Any allergies you may have
  • Current medicines, herbs, and supplements that you take and whether you need to stop taking them before surgery
  • Fasting before surgery, such as avoiding food or drink after midnight the night before
  • Whether you need a ride to and from surgery
  • Tests that will need to be done before surgery, such as an x-ray or an MRI scan


The doctor may give:

Description of the Procedure

A tendon in the knee or hamstring will be used to reconstruct the torn ligament. Sometimes a donor graft is used. The tendon will be formed to the correct size.

A few small incisions will be made on the top of the knee. Tools will be placed through the incisions. The torn ACL will be removed. Any other damage to the knee may also be repaired. Holes will be drilled through bones in the thigh and shin. The new graft will be placed through these holes. Needles may be threaded through the holes to hold the new tendon in place. Other devices, such as screws, washers, or staples are also used to hold the graft in place. The incisions will be closed with stitches.

Once the graft is securely in place, the knee’s range of motion will be tested. Other tests will be done as well. The skin will be closed with stitches. Bandages will be used.

How Long Will It Take?

About 2 hours

Will It Hurt?

Pain and swelling are common in the first 1 to 2 weeks. Medicine and home care can help manage it.

Average Hospital Stay

You may be able to go home the same day. If you have problems, you may need to stay longer.

Post-procedure Care

At the Hospital

After the procedure, the staff may:

  • Give you pain medicines
  • Protect the knee with a brace or splint
  • Teach you how to walk with crutches

During your stay, staff will take steps to lower your chance of infection, such as:

  • Washing their hands
  • Wearing gloves or masks
  • Keeping your incisions covered

You can also lower your chance of infection by:

  • Washing your hands often and reminding visitors and staff to do the same
  • Reminding staff to wear gloves or masks
  • Not letting others touch your incisions
At Home

It will take a few weeks for the incisions to heal. Physical activity will need to be limited during recovery. You will need to ask for help with daily activities and delay your return to work. Full recovery can take up to a year.

Call Your Doctor

Call your doctor if you are not getting better or you have:

  • Signs of infection, such as fever and chills
  • Redness, swelling, more pain, a lot of bleeding, or any leaking from incisions
  • Swelling, pain, or heat in your calves
  • Pain that you can't control with medicine
  • Nausea or vomiting
  • Cough, shortness of breath, or chest pain
  • Numbness in the knee
  • New or worsening symptoms

If you think you have an emergency, call for medical help right away.


American Orthopaedic Society for Sports Medicine 

Ortho Info—American Academy of Orthopaedic Surgeons 


Canadian Orthopaedic Association 

Canadian Orthopaedic Foundation 


American Academy of Orthopaedic Surgeons (AAOS). Evidence-based clinical practice guideline for management of anterior cruciate ligament injuries. AAOS 2014 Sep 5 PDF.

Anterior cruciate ligament (ACL) injury. EBSCO DynaMed website. Available at: . Updated June 26, 2017. Accessed July 17, 2020.

Anterior cruciate ligament injuries. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at: Updated March 2014. Accessed July 17, 2020.

Knee ligament repair. Johns Hopkins Medicine website. Available at.,P07675/. Accessed July 17, 2020.

Revision Information