ACL Reconstruction

What this procedure is

ACL reconstruction is a surgery used to replace a torn anterior cruciate ligament (ACL). The ACL is a strong band of tissue located in the middle of your knee. It connects your thigh bone to your shin bone and helps keep your knee stable when you move or turn.

Because a torn ACL usually cannot be sewn back together, a surgeon replaces the damaged ligament with a "graft." A graft is a piece of healthy tissue, often a tendon, taken from another part of your leg or from a donor. This new tissue acts as a scaffold for a new ligament to grow on.

Your clinician may use a small camera called an arthroscope to see inside the knee during the procedure. This often allows for smaller incisions (cuts) and a focus on protecting the surrounding healthy tissue while the graft is put in place.

What it treats or fixes

This procedure is used to treat a complete tear of the ACL. When this ligament is damaged, the knee often feels unstable or may "give out" during physical activity. This can make it difficult to walk, climb stairs, or play sports.

The main goals of the surgery include:

• Restoring stability: Helping the knee stay in place during movement.
• Improving function: Allowing you to return to the activities you enjoy.
• Protecting the knee: Reducing the risk of further injury to other parts of the knee, such as the cartilage.

While not everyone with an ACL tear needs surgery, your clinician may recommend it if you are active, have a high level of instability, or have injured other parts of your knee at the same time.

How common it is & where it's done

ACL reconstruction is a very common orthopedic procedure in the United States and Canada. It is performed frequently on athletes of all levels, as well as people who have injured their knee during everyday activities or work.

This surgery is typically performed as an "outpatient" procedure. This means that most patients are able to go home the same day of the surgery after a short period of recovery in the clinic. It is usually done in a hospital or a specialized outpatient surgery center.

Before the procedure, your clinician may discuss the type of anesthesia used to keep you comfortable. Because it is a routine surgery, medical teams are very familiar with the steps needed to help you prepare and recover safely.

Recovery: What to Expect

Recovery is a gradual process that focuses on getting your knee moving again. Your clinician may recommend starting physical therapy—special exercises to improve movement and strength—shortly after surgery.

In the first few weeks, the goal is to reduce swelling and regain the ability to straighten your leg. You might use crutches or a brace for a short time to protect the new graft (the piece of tissue used to replace your ACL).

Full recovery usually takes several months. Most people can return to sports or high-impact activities within 6 to 12 months, depending on how their strength progresses.

Risks & Possible Complications

Like any surgery, ACL reconstruction has some risks. These may include:

• Bleeding or infection
• Blood clots in the leg
• Knee pain or stiffness
• The graft not healing properly or tearing again

Your surgical team takes many steps to minimize these risks. You should contact your clinician if you notice signs like a high fever, a sudden increase in pain that does not improve with rest, or unusual redness and warmth around the incision.

Outcomes & Long-Term Results

The long-term goal of surgery is to provide a stable knee that allows you to return to your favorite activities. Most patients who follow their physical therapy plan see very positive results and can get back to their previous level of function.

Success often depends on your commitment to the rehabilitation program. Staying active and keeping the muscles around your knee strong can help protect the joint for years to come.

Emotional Support & Reassurance

It is normal to feel a bit nervous about surgery and the road to recovery. Remember that ACL reconstruction is a very common procedure, and your healthcare team is there to support you every step of the way.

Focusing on small, daily goals during physical therapy can help you stay positive. With patience and steady effort, most people find they can return to the lifestyle they enjoy.

Why doctors recommend it

The ACL (anterior cruciate ligament) is a tough band of tissue that helps hold your knee together and keep it stable. Your clinician may recommend surgery if your knee feels unstable or "gives out" during daily activities. This is often the case for people who want to return to sports that involve jumping, cutting, or pivoting.

For some, physical therapy alone might be enough to manage the injury. However, if the knee remains loose, it can cause more damage to other parts of the joint, such as the meniscus (the rubbery cushions between your bones). Surgery is often suggested to help protect the long-term health of your knee joint.

Urgent vs planned treatment

ACL reconstruction is rarely an emergency. In most cases, it is a planned procedure. Your surgical team may suggest waiting a few weeks after the injury to allow the initial swelling to go down and for you to regain your range of motion, which is how well you can bend and straighten your leg.

During this waiting period, your clinician may recommend "pre-hab." This is a type of physical therapy done before surgery to strengthen the muscles around the knee. Starting surgery with a stronger, more mobile knee often leads to a smoother recovery afterward.

Goals of treatment

The main goal of this surgery is to make your knee stable again. By replacing the torn ligament with a new graft, which is a piece of healthy tissue, the surgeon aims to stop the knee from shifting or buckling. This helps you feel more confident when walking, running, or playing sports.

Other goals of treatment include:

• Restoring function: Helping you get back to the activities you enjoy.
• Protecting the joint: Reducing the risk of future wear and tear that can lead to arthritis.
• Improving strength: Working with physical therapy to rebuild the muscles that support the knee.

Success is usually measured by your ability to return to your daily routine safely and without the feeling that your knee is unstable.

Who may benefit

ACL reconstruction is often a good choice for active individuals who want to return to sports that involve jumping, pivoting, or sudden changes in direction. This includes activities like soccer, basketball, or skiing. If your knee frequently feels unstable or "gives out" during your normal routine, surgery may help you regain confidence in your movement.

Your clinician may also recommend surgery if you have injured more than one part of your knee. For example, if you have a torn meniscus (the cushion-like cartilage in the joint) along with an ACL tear, a surgical approach might provide the best long-term results for your joint health.

When it may not be the right option

Surgery may not be necessary for everyone with an ACL injury. If you have a partial tear and your knee remains stable during daily tasks, your care team might suggest starting with physical therapy. This non-surgical path focuses on strengthening the muscles around the knee to support the joint.

For individuals who do not participate in high-impact sports or those who are older and less active, the risks of surgery might outweigh the benefits. Additionally, if you have significant arthritis in the knee, your clinician may discuss other ways to manage your symptoms rather than reconstructing the ligament.

Questions to ask your care team

Choosing the right treatment is a shared decision between you and your healthcare providers. Here are some questions you may want to bring to your next visit:

• Based on my activity level, what are the benefits of surgery versus non-surgical treatment?
• What type of graft—using your own tissue or donor tissue—is best for my situation?
• What does the timeline for physical therapy look like after the procedure?
• When can I safely return to work or my favorite physical activities?
• What are the most common risks I should be aware of?

In the procedure room

When you enter the procedure room, the surgical team will help you get settled comfortably on the operating table. The room is kept very clean and contains specialized equipment for the surgery.

The team will clean the skin around your knee with a special soap to help prevent infection. They will then place sterile drapes around your leg to keep the area clean throughout the process.

High-level steps

The surgeon usually performs this surgery using an arthroscope. This is a very small tube with a camera on the end that allows the doctor to see inside your knee on a video monitor without making large cuts.

• The surgeon makes a few small incisions (cuts) around the knee joint.
• The torn or damaged ACL is removed to make room for the new one.
• A graft—a piece of healthy tendon—is prepared. This graft will act as the new ligament. It may come from another part of your leg or from a donor.
• The surgeon drills small tunnels into the bone to position the graft correctly.
• The graft is secured into the bone using screws, staples, or other devices so it can heal in place.

Anesthesia and pain control

To keep you comfortable, your clinician may use general anesthesia, which means you will be in a deep sleep during the procedure. In other cases, they may use a regional block to numb only your leg.

As the medicine takes effect, you will not feel pain. After the surgery, you might notice a heavy or numb feeling in your leg as the anesthesia begins to wear off. This is a normal part of the process.

Monitoring and safety steps

Your safety is the top priority. During the entire surgery, a dedicated staff member will monitor your vital signs, including your heart rate, breathing, and blood pressure.

The surgical team also follows strict safety checks. They will confirm your identity and the specific details of your procedure multiple times to ensure everything is correct before they begin.

Immediately after the procedure

Once the surgery is finished, you will be moved to a recovery room. Nurses will stay with you as you wake up from the anesthesia. They will check your pulse and make sure you are comfortable.

Your knee will be wrapped in a sterile bandage, and you may be placed in a knee brace to keep the joint stable. You might feel some soreness or pressure in the knee, which is common. Your clinician may provide ice or pain medicine to help you feel better.

Typical procedure length

The surgery itself typically takes between 60 and 90 minutes. However, the exact time can vary depending on the specific needs of your knee and the type of graft used.

You should plan to be at the surgical center for several hours. This extra time allows for the necessary preparation before the surgery and a period of observation afterward to ensure you are ready to go home safely.

Common approaches (open vs minimally invasive)

ACL reconstruction is usually performed using a method called arthroscopic surgery. This is considered a minimally invasive approach. Instead of making one large, open cut to reach the knee joint, the surgeon makes a few small incisions.

A thin tool with a small camera, known as an arthroscope, is inserted through one of these cuts. This camera projects images onto a screen, allowing the surgeon to see the inside of the knee clearly without opening the joint completely. The surgeon then uses other small instruments to remove the damaged ligament and place the new tissue (graft).

Partial vs total

The approach your doctor chooses often depends on the severity of the injury. If the ACL is only partially torn and the knee remains stable, surgery may not be required. In these cases, nonsurgical options like physical therapy and bracing are often the first steps.

If the ligament is completely torn or the knee is giving way, a total reconstruction is typically performed. During this procedure, the torn ligament is removed entirely and replaced with a tendon graft to restore stability to the knee.

Revision or repeat procedures

While the goal of ACL reconstruction is a permanent fix, there are instances where the new ligament may not heal correctly or could tear again. If the first operation does not provide the expected stability, a second surgery may be necessary.

This follow-up procedure is called revision ACL reconstruction. It is performed to address issues from the initial surgery and help secure the knee joint again.

Tests and imaging that may be done

To plan your surgery, your doctor needs to see the inside of your knee clearly. They may order X-rays to look for any signs of bone injury. You may also need an MRI (magnetic resonance imaging) scan. This test shows the extent of the ACL tear and checks if other ligaments or cartilage in the knee are damaged.

Your care team also needs to make sure you are healthy enough for the procedure. Before surgery, you may need to have blood tests or an electrocardiogram (ECG) to check your general health and heart rhythm.

Medication adjustments

Tell your doctor about all the medicines you take. This includes prescription drugs, over-the-counter medicines, vitamins, and supplements.

Some medicines, such as aspirin or ibuprofen, can increase the risk of bleeding. Your surgeon may ask you to stop taking these specific drugs for a period of time before your surgery. Always follow your clinician's specific instructions before stopping or changing any medication.

Day-before and day-of instructions

Your surgical team will give you a list of steps to follow to ensure your safety during the procedure. Common instructions include:

• Fasting: You will likely be told when to stop eating and drinking before the surgery. It is important to follow these rules exactly to avoid complications with anesthesia.
• Transportation: You will not be able to drive yourself home after the procedure. You must arrange for a friend or family member to pick you up and drive you home.

General surgical risks

As with any surgical procedure, there are standard risks to consider. These generally include bleeding or infection at the site of the surgery. There is also a possibility of blood clots forming in the legs or lungs.

Your surgical team takes precautions to minimize these risks. Be sure to discuss your specific medical history with your doctor, as certain conditions may affect your risk level.

Procedure-specific complications

In addition to general risks, there are potential complications specific to ACL reconstruction. Some patients may experience continued knee pain or find that the surgery does not fully relieve their symptoms.

Other specific risks may include:

• Stiffness or weakness in the knee
• Loss of range of motion (difficulty bending or straightening the knee fully)
• Incorrect healing of the graft (the new tissue used to replace the ligament)

How complications are treated

Your healthcare provider will monitor your recovery to catch and address any issues early. Because risks can depend on your specific medical condition, your doctor will discuss any concerns with you prior to the procedure.

If you experience stiffness, weakness, or other healing issues, your care team will adjust your treatment plan to help manage these symptoms. Always let your clinician know if you notice changes in your recovery.

Pain control medicines

Managing discomfort is a key part of the recovery process after ACL reconstruction. Your clinician may suggest using different types of medicine to help you stay comfortable. This often includes NSAIDs (non-steroidal anti-inflammatory drugs) to help with both pain and swelling, or acetaminophen.

For the first few days after surgery, your clinician may also provide stronger prescription medicines. These are typically used for a short time to help you get through the initial healing phase. It is important to share your full medical history with your team to avoid potential drug interactions or allergic reactions.

Antibiotics

Preventing infection is a priority during any surgical procedure. Your clinician may give you antibiotics, which are medicines used to fight bacteria. These are often given through an IV (a small tube in the vein) shortly before the surgery starts to ensure they are in your system during the procedure.

Your clinician will tailor the use of these medicines based on your health history. If you have any known allergies to specific antibiotics, such as penicillin, make sure to inform your surgical team before your procedure date.

Blood thinners and clot prevention

Because you will be less mobile while your knee heals, there is a small risk of blood clots forming in the legs. To help prevent this, your clinician may recommend medicines known as anticoagulants, or blood thinners. These medicines help keep the blood from sticking together too easily.

Commonly, a simple regimen like low-dose aspirin is used, but your clinician will decide what is best for you. They will consider your overall health and any other medications you are currently taking to ensure the plan is safe and effective for your recovery.

Emergency warning signs

Although ACL reconstruction is generally safe, complications can happen. According to medical experts, blood clots are a known risk of this surgery. Bleeding is another potential complication to be aware of.

If you suspect you have a blood clot or are experiencing uncontrolled bleeding, seek medical care right away.

Call your surgeon or clinic if…

Your healthcare provider will monitor your recovery, but you should contact them if you notice signs of a problem. Infection is a risk following surgery, so reach out if you believe the surgical area is infected.

You should also call your clinician if you experience:

• Knee stiffness or unexpected weakness
• Loss of range of motion (difficulty moving the knee)
• Signs that the knee is not healing properly

Expected vs concerning symptoms

Expected symptoms: It is normal to have pain after the procedure. Your healthcare provider will likely give you pain medicines to help manage this. You may also need to use crutches and wear a knee brace while you recover. Physical therapy is a standard part of the healing process.

Concerning symptoms: While recovery takes time, improper healing or graft failure are possible risks. If your knee remains stiff, weak, or does not seem to be recovering as planned, discuss these concerns with your doctor.

Non-surgical treatments

For some people, surgery may not be the first step. Your clinician may suggest physical therapy to strengthen the muscles around your knee. This includes the quadriceps (the muscles on the front of your thigh) and the hamstrings (the muscles on the back of your thigh). Stronger muscles help support the joint and take pressure off the injured ligament.

You might also use a knee brace. A brace provides extra stability from the outside to keep the knee from shifting during movement. Along with therapy, your clinician may recommend changing your activities. This often means avoiding sports that involve quick turns, jumping, or pivoting while the knee heals.

Watchful waiting

Watchful waiting is a period where you and your care team monitor how your knee responds to non-surgical care. During this time, you focus on rehabilitation (rehab) to see if your knee can stay stable during your normal daily routine. This approach is often used for patients who have a less active lifestyle or a partial tear.

The goal is to see if you can reach your physical goals without an operation. If your knee feels strong and does not "give out" during your daily activities, you may be able to continue without surgery. Your clinician will check your progress regularly to ensure the joint remains healthy and functional.

When surgery becomes the best option

Surgery is often considered when non-surgical methods do not provide enough stability for your needs. If your knee continues to feel unstable or "buckles" during simple activities, your clinician may recommend reconstruction. This is important because repeated instability can lead to further damage, such as tears in the meniscus (the cushion-like cartilage in the knee).

Your lifestyle and goals also play a big role in this decision. Surgery is frequently the best option for:

• Athletes: Those who want to return to sports that require pivoting, jumping, or hard cutting.
• Combined injuries: If you have injured other ligaments or cartilage in the knee at the same time.
• Active individuals: Younger people who need a stable knee for many years of high-level activity.

Hospital services that commonly perform this surgery

ACL reconstruction is typically performed in specialized hospital departments or outpatient centers. Most often, you will visit an orthopedic department, which focuses on bones, joints, and ligaments. Many hospitals also have dedicated sports medicine centers that specialize in treating active individuals and athletes.

These facilities are equipped with advanced technology for arthroscopy. This is a surgical technique where a tiny camera and small tools are used to repair the knee through small incisions. Because this is often an outpatient procedure, these centers have recovery areas designed to help you get ready to go home safely on the same day.

Patient resources and support services

Recovery from ACL surgery involves more than just the operation. Most hospitals provide access to physical therapy (PT) services. Physical therapists are experts who guide you through specific exercises to help your knee regain its strength and range of motion, which is how far you can move your joint.

Your clinician may also suggest using these common support services:

• Sports medicine clinics: These provide specialized care for returning to sports or high-level activity.
• Educational materials: Many centers provide booklets or videos that explain what to expect before, during, and after surgery.
• Pain management teams: These specialists help ensure you are comfortable during your initial recovery.

Questions for choosing where to have surgery

Choosing the right place for your surgery can help you feel more confident. Your clinician may suggest looking for a facility that performs many of these procedures each year. You might consider asking the following questions when choosing a facility:

• How many ACL reconstructions does the surgical team perform each year?
• Is the surgery performed in a full hospital or an outpatient surgical center?
• Does the facility have an on-site physical therapy department to help with my recovery?
• What kind of support is available if I have questions or concerns after I go home?
• How does the team coordinate care between the surgeon and the physical therapist?

Conditions commonly treated by this procedure

ACL reconstruction is primarily used to treat a tear of the anterior cruciate ligament (ACL). The ACL is a strong band of tissue located in the center of the knee that helps keep the joint stable and prevents the shin bone from sliding out in front of the thigh bone. Your clinician may recommend this surgery if the ligament is completely torn or if a partial tear makes the knee feel unstable during daily activities or sports.

It is common for an ACL injury to happen alongside other damage inside the knee. This can include tears to the meniscus, which are the C-shaped pieces of cartilage that act as shock absorbers between your bones. Other ligaments, such as the medial collateral ligament (MCL), may also be injured at the same time. A surgical team may address these related conditions during the reconstruction to help the knee heal properly.

Related symptoms people search for

Symptoms of an ACL injury often appear suddenly. Many people report hearing or feeling a loud "pop" in the knee at the moment the injury occurs. This is usually followed by significant swelling that develops within a few hours and a feeling of deep pain within the joint. Because these signs can be associated with several types of knee injuries, a clinician should perform an evaluation to determine the cause.

Other symptoms that may lead a person to consider reconstruction include:

• Instability: A feeling that the knee is "giving out" or is untrustworthy, especially when trying to pivot, turn, or step to the side.
• Loss of range of motion: Difficulty fully straightening or bending the knee as you normally would.
• Discomfort while walking: Pain that makes it hard to put weight on the leg or a feeling of wobbliness when standing.
• Tenderness: Soreness along the joint line where the bones meet.

Evidence overview

ACL reconstruction is a widely performed surgery designed to restore stability to the knee after a tear in the anterior cruciate ligament. Medical professionals typically recommend this procedure for active individuals who wish to return to sports or jobs that require pivoting, turning, or heavy physical activity. The goal is to prevent the knee from giving way and to protect the joint from further damage.

To determine if surgery is the right path, clinicians use established diagnostic tools. This usually begins with a physical exam to test the looseness of the knee. Imaging tests, such as an MRI (magnetic resonance imaging), are used to confirm the tear and check for damage to other parts of the knee, such as cartilage. X-rays may also be taken to rule out bone fractures.

Safety notes and individualized care

While ACL reconstruction is a common procedure, all surgeries carry some risks. Your surgical team will take steps to minimize complications, but potential risks can include bleeding, infection, and blood clots. Some patients may experience continued knee stiffness, pain, or a limited range of motion after the operation. There is also a chance that the new ligament graft could fail or tear again.

Treatment plans are highly individualized based on age, activity level, and the severity of the injury. For example:

• Children: Because young athletes are still growing, surgeons take special care to avoid damaging growth plates during the procedure.
• Less active adults: Older patients or those who do not play agility sports might be advised to manage the injury without surgery, using physical therapy and bracing instead.
• Graft choice: The surgeon may use a tendon from your own body (autograft) or donor tissue (allograft), depending on your specific medical needs.

Recovery requires commitment to physical therapy. Following your clinician’s instructions regarding rest, ice, compression, and elevation (RICE) is essential for safe healing.

Sources used

The information provided in this section is based on patient education materials from major academic medical centers and reputable healthcare organizations specializing in orthopedics and sports medicine.