ACL Tear & Injury: Symptoms & Recovery

By: Dr. Vijaykumar D
Consultant - Sports Surgery and Ankle Foot
Posted on March 4, 2025

Anything that puts enough force on your knee to bend or twist it farther than its natural limit can tear your ACL.

The ACL is one of your knee ligaments. It connects your thigh bone (femur) to your shin bone (tibia). You have one ACL in each knee. It forms an “X” shape inside your knee with your posterior cruciate ligament (PCL). The ACL is closer to the front of your knee. The PCL is closer to the back of your knee.

Your ACL is like a strap that connects your bones and prevents your knee from bending or rotating too much. Anything that puts enough force on your knee to bend or twist it farther than its natural limit can injure or tear your ACL.

ACL tears are a common injury, especially among athletes. Visit a healthcare provider if your knee hurts, particularly if the pain started after an injury or physical activity.

What is an ACL tear?

An ACL tear is an injury to your knee’s anterior cruciate ligament (ACL).

The ACL is the most commonly injured knee ligament. Sports injuries usually cause ACL tears. If you tear your ACL, you’ll probably need surgery to reconstruct it. Most people who tear their ACL make a full recovery and resume playing sports with no long-term consequences. The recovery time for a torn ACL is usually six to nine months.

Different Grades of ACL Tears

ACL injuries are classified into three grades based on severity:

Grade 1 (Mild Sprain)

The ACL is stretched but not torn.
Knee stability is mostly intact.
ACL sprain recovery time is typically 2–6 weeks with physiotherapy.

Grade 2 (Partial Tear)

The ligament is partially torn, affecting knee stability.
Moderate swelling and difficulty walking.
Recovery may take several months with proper rehabilitation.

Grade 3 (Complete Tear or Rupture)

The ligament is completely torn, causing severe instability.
Surgery is often required for full recovery.
ACL rupture treatment includes surgery and a rehabilitation program lasting 6–12 months.

How common are ACL injuries?

ACL injuries and tears are very common. The ACL is the most commonly injured knee ligament. Experts estimate that between 100,000 and 200,000 people in the U.S. tear an ACL each year.

What does an ACL tear feel like?

Most people know the moment they tear their ACL. Sports injuries and other traumas that tear your ACL are usually obvious enough that you can say exactly when it happened.

People who experience an ACL tear usually feel or hear a pop in their knee. Their knee might give out (feel unstable and weak). ACL tears can be very painful, with knee swelling, but some people only feel small discomfort and instability. Visit an orthopaedic doctor if you injured your knee, especially if you hear or feel a popping.

Symptoms of an ACL Tear

The severity of symptoms depends on the extent of the injury. Some of the most common ACL sprain symptoms include:

1. Popping Sound at the Time of Injury

Many people report hearing or feeling a loud “pop” when the ligament tears. This is often the first sign of an ACL injury.

2. ACL Pain Location

Pain is usually felt deep inside the knee, particularly at the centre or along the joint line. It may intensify when trying to bear weight.

3. Swelling and Inflammation

Swelling develops rapidly within a few hours due to internal bleeding in the knee. It may cause stiffness, limiting movement.

4. Knee Instability

An injured ACL compromises knee stability, making it difficult to stand, walk, or pivot. Many individuals feel like their knees might “give out.” Difficulty in climbing stairs, specifically Climbing downstairs

5. Reduced Range of Motion

Bending or fully straightening the knee becomes painful and difficult due to swelling and joint stiffness.

If left untreated, an ACL tear can lead to chronic knee instability and increase the risk of further injuries, such as cartilage damage requiring cartilage repair.

What Causes an ACL Tear?

ACL injuries typically occur due to excessive strain on the ligament. ACL tears happen when your knee moves or twists more than it naturally can. The most common causes include:

1. Sudden Direction Changes

Quick turns, pivots, or side-step movements can overstretch the ACL, leading to tears.

2. Improper Landing from Jumps

Landing awkwardly after a jump increases stress on the knee, putting the ligament at risk.

3. Direct Impact or Trauma

A sudden blow to the knee, such as in contact sports or car/bike accidents, can rupture the ACL.

4. Overstretching or Hyperextension

Extending the knee beyond its normal range can strain and tear the ligament.

5. Weak Muscles or Poor Conditioning

Weak quadriceps and hamstrings fail to support the knee, increasing susceptibility to ligament injuries.

ACL tear risk factors

Anyone can experience an ACL tear. They’re much more common among athletes, especially those who play sports that involve suddenly stopping, twisting or changing directions. Some sports that cause frequent ACL tears include:

Soccer.
Football.
Basketball.
Gymnastics.

What are the complications of an ACL tear?

The injuries that cause ACL tears can damage other parts of your knee, too.

You might damage or tear your other knee ligaments during an ACL tear, including your:

Medial collateral ligament (MCL).
Lateral collateral ligament (LCL).
Posterior cruciate ligament (PCL).

Other injuries that can occur at the same time as an ACL tear include:

Bone fractures.
Meniscus tears.
Muscle strains.

Diagnosis and Tests

How are ACL tears diagnosed?

A doctor will diagnose an ACL tear by performing a physical exam and some tests. They’ll ask you about your symptoms and look at your knee. Tell your doctor what you were doing right before you hurt your knee and when you first noticed symptoms.

Your doctor might perform some movements or motions with your knee and leg. These tests might feel uncomfortable. Tell your doctor if any position or motion hurts or worsens your symptoms.

You’ll probably need a few imaging tests, including:

X-rays.
A computed tomography (CT) scan.
Magnetic resonance imaging (MRI) – Investigation of choice to diagnose ACL tear and to plan for surgery

Treatment Options for an ACL Tear

Treatment depends on the severity of the tear and the patient’s lifestyle.

1. Conservative Treatment (Non-Surgical Approach)

For mild ACL injuries or partial tears, healing ACL without surgery is possible through:

Rest & Ice Therapy: Reduces pain and swelling.
Compression & Elevation: Supports healing and prevents further damage.
Bracing: A knee brace stabilises the joint and prevents excessive movement.
Physical Therapy: Strengthening surrounding muscles improves knee stability.

This approach works well for non-athletes or individuals with a sedentary lifestyle.

2. ACL Knee Surgery (Reconstruction Surgery)

For complete ACL ruptures, surgery is often required, especially for active individuals or athletes.

Arthroscopic ACL Reconstruction: The damaged ligament is replaced with a graft from the patient’s hamstring, patellar tendon or peroneus longus tendon.
Minimally Invasive Surgery: Reduces recovery time and post-operative pain.

Post-surgical rehabilitation is crucial for regaining full knee function.

Recovery & Rehabilitation

Recovery time varies depending on the severity of the injury and treatment method.

Post-Surgery Recovery Timeline

First 2 Weeks: Focus on reducing swelling and regaining knee mobility.
Weeks 3–6: Start light exercises and strengthen surrounding muscles.
Months 3–6: Intensive physiotherapy and sport-specific training.
6+ Months: Return to sports or full physical activity with caution.

ACL Rehabilitation

A structured physiotherapy program includes strengthening and mobility exercises. These exercises prevent stiffness and ensure the knee regains full function.

Conclusion

An ACL tear can significantly impact your life, but with proper treatment and rehab, full recovery is possible. Whether choosing physical therapy or ACL surgery, following a structured recovery plan is crucial for restoring knee function. If you’re dealing with an ACL injury, seeking timely care from an Orthopedic Doctor in Bangalore at a trusted Orthopedic Hospital in Bangalore can help you get back to daily activities and sports safely

A note from SPARSH Hospital Sports Injury Team Lead by Dr Vijay Kumar D

ACL tears are one of the most common knee injuries athletes experience. It can be extremely frustrating to miss months of practice, games or training sessions, but don’t rush your recovery. If you need surgery for Reconstruction of your ACL, you should be able to return to the field or court as soon as your knee has healed.

Don’t force yourself to use your knee if it’s hurt. Extra stress can make a lower grade ACL tear worse. Visit us as soon as you injure your knee or feel pain to get best treatment available at SPARSH Hospital, Bangalore.

Care at SPARSH Hospital

An ACL tear hurts and can keep you from being active. The Orthopaedic Sports injury Team at SPARSH Hospital, led by Dr Vijay D, will provide you with world-class treatment, including reconstruction of your torn ACL and post-operative physiotherapy, and help you get back on your feet.

Frequently Asked Questions

Prevention

How can I prevent a torn ACL?

There might not be any way to prevent an ACL tear, especially if you’re an athlete. Sports injuries and accidents you can’t plan for usually cause ACL tears.
During sports or other physical activities:

Wear the proper protective equipment.
Don’t “play through the pain” if your knee hurts during or after physical activity.
Give your body time to rest and recover after intense activity.
Stretch and warm up before playing sports or working out.
Cool down and stretch after physical activity.

Off-season knee and lower body strengthening programs can help prepare your knee joints for the stress a sports season puts on them.

Follow these general safety tips to reduce your risk of an injury:

Avoid planting your foot and pivoting over your knee. This is a common way athletes injure their ACL and meniscus.
Make sure your home and workspace are free from clutter that could trip you or others.
Always use the proper tools or equipment at home to reach things. Never stand on chairs, tables, or countertops.
Use your cane or walker if you have difficulty walking or have an increased risk of falls.

Prognosis

Can an ACL tear heal on its own?

A torn ACL can’t heal on its own, but it’s possible to live with it (especially if you have a low-grade tear). But if you’re an athlete/young adult or want to return to physical activity, you’ll need surgery to reconstruct your ACL. Most people choose to have an ACL tear surgically repaired.

Can you walk if your ACL is torn?

Some people can walk with a torn ACL. But don’t force yourself to move or use your knee if it hurts. Visit an Orthopaedics Surgeon when you feel pain or have other knee injury symptoms. Putting more stress on your injured ACL can make a small tear worse.

Is an ACL tear a serious injury?

Yes, an ACL tear affects knee stability and can lead to long-term complications if untreated. Severe cases require surgery for full recovery.

Can I live a normal life with a torn ACL?

With rehabilitation, many people resume normal activities, but high-impact sports may be challenging without surgical repair.

Is an ACL tear a life-changing injury?

For athletes and active individuals, it can be a significant setback, but with proper treatment, most people recover well and regain knee function.

How long does it take to recover from a torn ACL?

It usually takes six to nine months to recover from a torn ACL after surgery and post-operative physiotherapy. Competitive athletes may need a little longer than this to heal fully before they’re cleared to return to their sport.

Will an ACL tear happen again?

There’s a small chance you’ll tear the same ACL again in the future, even if you have surgery to repair it. Fewer than 10% of people who have a torn ACL tear that same ACL again. Talk to your surgeon about what to expect.

Is an ACL tear “career-ending” for an athlete?

Most ACL tears aren’t career-ending. Just make sure you don’t rush your recovery. Most people who experience a torn ACL can return to their sport with no long-term consequences. Rehabilitation after your surgery is the best way to restore your knee’s strength and flexibility. You’ll need to rehab your knee over time before you can return to your sport.

Ask your treating orthopaedics surgeon if it’s safe for you to play the same sport again and when you can resume practice or training.

When should I see an Orthopaedics Surgeon?

If you experience persistent knee pain, swelling, or instability, it is advisable to seek expert care. Visit an orthopaedic surgeon as soon as possible after you injure your knee. Talk to your doctor if you notice new symptoms or if the pain is getting worse.

You can consult some of the best orthopaedic doctors in Bangalore at SPARSH, which is renowned as one of the best orthopaedic hospitals in Bangalore, for specialised treatment.