ACL Tear Grades: Grade 1, 2 & 3 ACL Injury Classification, Treatment & Recovery in Bengaluru

If you have been told you have an ACL injury, one of the first questions you will have is how serious it is. Doctors often describe an anterior cruciate ligament (ACL) injury as Grade 1, Grade 2 or Grade 3, depending on how much of the ligament is damaged. Understanding these grades helps you make sense of your scan report, your treatment options and how long recovery may take.

At Sports Orthopedics Institute in HSR Layout, Bengaluru, we treat ACL injuries in footballers, badminton and basketball players, cricketers, kabaddi players, runners and weekend athletes. This guide explains each grade, how ACL injuries are diagnosed, and what the evidence says about treatment and recovery.

Key Takeaways

• ACL injuries are graded by how much of the ligament is torn: Grade 1 (stretched), Grade 2 (partial tear) and Grade 3 (complete rupture).
• Most ACL injuries that reach a specialist are complete tears. Isolated Grade 1 and partial tears are less common.
• The grade is only one part of the decision. Knee stability, age, activity level, sport and associated injuries matter as much as the grade.
• Grade 1 injuries are treated with rehabilitation. Grade 3 tears in active people are usually treated with ACL reconstruction, although rehabilitation is a reasonable option for some patients.
• Return to pivoting sport after reconstruction is usually at least 9 months, and should be based on strength and hop tests, not just the calendar.

Understanding the ACL

The anterior cruciate ligament is a strong band of tissue inside the knee, connecting the thighbone (femur) to the shinbone (tibia). On average it is roughly 32 mm long and about 10 mm wide. It does two main jobs:

• It stops the shinbone from sliding too far forward under the thighbone
• It controls rotation of the knee during pivoting and cutting

The ACL has two functional bundles. The anteromedial bundle is the main restraint against forward sliding, particularly when the knee is bent, while the posterolateral bundle is more important when the knee is nearly straight and for rotational control.

How ACL injuries happen

Roughly 70% of ACL injuries happen without contact from another player. Typical situations include:

• Pivoting with the foot planted, common in football, basketball and kabaddi
• Landing from a jump, common in volleyball, basketball and badminton
• Sudden deceleration or a sidestep, common in football and cricket fielding
• Hyperextension during a fall or awkward landing
• Direct contact, such as a tackle to the side of the knee

Female athletes have a higher risk of ACL injury than male athletes in the same sport.

How Are ACL Tears Graded?

ACL injuries are described using a three-grade system based on how many fibres are damaged:

Grade	Description	What it means
Grade 1	Mild sprain: fibres are stretched, with microscopic tearing	Ligament is intact and the knee is usually stable
Grade 2	Partial tear: some fibres are torn, others intact	Knee may be loose or unstable, especially with twisting
Grade 3	Complete rupture: all fibres are torn	Ligament no longer works; knee is usually unstable

A few important points:

• The grading is descriptive, and different clinicians and radiologists may use slightly different terms. Many surgeons simply say "partial" or "complete" tear.
• A "partial" tear is not always stable. Treatment depends on how the knee behaves, not only on the label.
• Partial tears can sometimes progress to complete tears, particularly if the knee keeps giving way.

Grade 1 ACL Tear (Mild Sprain)

In a Grade 1 injury the ligament is stretched and has microscopic tears, but remains in one piece and the knee is still stable.

Symptoms

• Mild to moderate pain
• Mild swelling, which may appear gradually over a day or two
• Tenderness around the knee
• Little loss of function, and you can usually walk
• Usually no audible pop
• Some stiffness, particularly in the morning

Examination and MRI

• Lachman test: only a slight increase in forward movement of the shinbone compared with the other knee, with a firm end-point
• Pivot shift test: usually negative
• MRI: increased signal within the ligament, but its fibres remain continuous

Treatment and recovery

Grade 1 injuries are treated without surgery. In the first days, the PEACE principles are often used:

• Protect the knee from painful activity
• Elevate the leg
• Avoid routine anti-inflammatory medication unless your doctor advises it
• Compress with a bandage or sleeve
• Educate yourself about the injury and recovery

Then the LOVE principles guide recovery: Load the knee gradually, keep an Optimistic outlook, promote blood flow (Vascularisation) with activity and Exercise.

A typical timeline is:

• Weeks 1–2: manage pain and swelling, regain range of motion
• Weeks 2–4: progressive strengthening
• Weeks 4–6: return to normal daily activities
• Weeks 6–8 and beyond: graded return to sport once the knee is strong, stable and pain-free

Most Grade 1 injuries do well with rehabilitation, but your timeline depends on how the knee responds.

Grade 2 ACL Tear (Partial Tear)

A Grade 2 injury means part of the ligament is torn while some fibres remain. It is less common than a complete tear and can be harder to diagnose.

Symptoms

• Moderate pain, worse with movement
• Swelling that develops within hours
• Difficulty putting full weight on the leg at first
• A feeling that the knee is loose or unstable
• Sometimes a pop at the time of injury
• Difficulty with stairs, twisting and pivoting

Examination and MRI

• Lachman test: increased forward movement with a softer end-point
• Anterior drawer test: may be positive
• Pivot shift test: may be positive if the knee is unstable
• MRI: shows some fibres disrupted and others intact. MRI is less accurate for partial tears than for complete ones, and arthroscopy sometimes gives the final answer.

Treatment: surgery or not?

There is no single correct answer for Grade 2 tears. The key question is whether the knee is stable and what you need it to do.

Rehabilitation first is reasonable for people who:

• Have a stable knee on examination
• Have lower-demand activities or are older
• Do not play pivoting or cutting sports
• Have no significant associated injuries

A structured programme usually lasts about 8 to 12 weeks, covering protection and early movement, then strengthening and balance training, then preparation to return to activity.

Surgery may be considered for people who:

• Continue to have the knee giving way despite rehabilitation
• Play football, basketball, badminton, kabaddi or other pivoting sports at a high level
• Have an associated meniscus or cartilage injury that needs treatment
• Are young and have high activity demands

Options include ACL reconstruction and, in selected cases, techniques that preserve the remaining fibres or add support to the ligament. These are less established than standard reconstruction, so ask your surgeon about the evidence.

Grade 3 ACL Tear (Complete Rupture)

In a Grade 3 injury, the ligament is torn completely and no longer controls the knee.

Symptoms

• Severe pain at the time of injury
• An audible or felt pop in many patients
• Inability to continue playing
• Rapid swelling, often within a few hours, because of bleeding into the joint
• Difficulty bearing weight at first
• A feeling of the knee giving way, especially with twisting

Later symptoms can include repeated giving way, trouble with stairs and pivoting, and persistent swelling or thigh muscle weakness.

Examination and MRI

• Lachman test: a marked increase in forward movement with a soft or absent end-point
• Anterior drawer test: positive
• Pivot shift test: positive, showing rotational instability
• MRI: shows complete discontinuity of the ligament. Bone bruising is common on the outer thigh bone and the back of the shin bone's outer surface.
• Associated injuries: more than half of acute complete tears have a meniscus tear, cartilage injury or another ligament injury

Treatment

ACL reconstruction is generally recommended for people who:

• Are young and active, or play pivoting sports
• Have recurrent giving way
• Have an associated injury, such as a meniscus tear, that needs surgery
• Have a job that requires a stable knee

The torn ligament is replaced with a graft, commonly taken from the hamstring tendons, the patellar tendon or the quadriceps tendon. Donor tissue (allograft) is used in specific situations, such as revision surgery. The operation is done arthroscopically, and many patients go home the same day or after one night.

Rehabilitation without surgery is a legitimate option for some patients. In a well-known randomised trial (the KANON study), young active adults who started with structured rehabilitation, with surgery only if needed, had similar outcomes at 2 and 5 years to those who had early reconstruction. However, about half of those in the rehabilitation group went on to have surgery later. Non-surgical treatment suits people with lower demands who are willing to avoid pivoting sports, and those with a knee that feels stable.

Recovery Timeline After ACL Reconstruction

Recovery is long, and rushing it is the main cause of re-injury. Your protocol will be set by your surgeon and physiotherapist.

Phase	Typical timing	Focus
1	Weeks 0–2	Control swelling, regain extension, activate the quadriceps, walk as advised
2	Weeks 2–8	Normal walking, full range of motion, progressive strengthening
3	Months 2–4	Advanced strengthening, balance, and start of running as cleared
4	Months 4–6	Agility, jumping and landing drills, sport-specific training
5	Months 6–9+	Return-to-sport testing and graded return; pivoting sport usually not before about 9 months

• Daily life: Most people walk the same day or the next and return to desk work within a few weeks.
• Return to sport: Studies show that returning to sport earlier than about 9 months, and without meeting strength and hop-test targets, significantly increases the risk of re-injury. We assess quadriceps and hamstring strength and hop tests (aiming for at least about 90% of the other leg) rather than relying on time alone.
• Mind and confidence: Fear of re-injury is common and affects whether athletes return to their previous level. Confidence-building drills are part of good rehab.

Outcomes and long-term considerations

• Most people regain a stable knee, but not everyone returns to their previous sport. Pooled studies show that around 80% return to some form of sport, about two-thirds return to their pre-injury level, and fewer return to competitive level.
• Graft re-rupture occurs in roughly 5 to 10% of patients overall, and is higher in young athletes who return to cutting and pivoting sports.
• An ACL injury increases the risk of knee osteoarthritis in the long term, whether or not you have surgery, especially if there is also a meniscus injury. Strengthening, weight management and following your rehab programme help protect the knee.

How Is an ACL Tear Diagnosed?

Clinical examination

• Lachman test: the knee is bent about 20–30 degrees and the shinbone is drawn forward. It is the most reliable test for ACL injury, with good sensitivity (about 85%) and specificity (about 94%) in pooled studies.
• Anterior drawer test: the knee is bent to 90 degrees. It is less reliable in the first days after injury because of pain and muscle spasm, and better in longstanding injuries.
• Pivot shift test: assesses rotational instability. It is very specific (about 98%) but not very sensitive (about 24%) in an awake patient, because pain and guarding make it hard to perform. It can be more informative under anaesthesia.
• Effusion, range of motion and joint-line tenderness: help identify swelling and associated injuries, such as meniscus tears

Examination can be difficult right after the injury because of pain and swelling, and it is often more reliable after the first few days.

Imaging

• MRI: the main test to confirm the tear, assess its extent, and check for meniscus, cartilage and other ligament injury. It is highly accurate for complete tears and less accurate for partial tears. A good MRI needs expert interpretation alongside the clinical examination.
• X-ray: does not show the ACL, but excludes fractures and checks the bones
• Arthroscopy: gives a direct view of the ligament and settles uncertain cases, usually as part of treatment

Sport-Specific Considerations

Sport	Considerations
Football	Frequent cutting, pivoting and tackles make an unstable knee risky. Complete tears in competitive players are usually treated with reconstruction.
Cricket	Fast bowlers and fielders put heavy rotational and deceleration loads on the knee. Return typically takes 9 months or more after reconstruction.
Badminton and tennis	Lunges, jumps and quick changes of direction on hard courts strain the ACL. Surgery is usually advised for competitive players with a complete tear.
Kabaddi	Raids and tackles combine contact with sudden twisting, so a reliable knee is essential.
Basketball and volleyball	Repeated jumping and landing make a stable knee important, and landing technique is a key part of rehab.

The decision is always individual and depends on your level of sport, your goals and how stable the knee is.

Preventing ACL Injuries and Re-Injury

For uninjured athletes

• Neuromuscular training programmes, such as FIFA 11+ and similar warm-up programmes, help reduce injuries
• Practise landing and cutting technique, with good knee and hip bend
• Strengthen the quadriceps, hamstrings, glutes and core
• Build balance and agility
• Increase training load gradually, and avoid playing when fatigued

After an ACL injury or reconstruction

• Complete every phase of rehabilitation, and pass return-to-sport tests
• Continue strength and neuromuscular training long term
• Keep a healthy body weight to reduce load on the knee
• Do not return to pivoting sport too early
• Address confidence and fear of re-injury

Having had an ACL injury significantly raises the risk of a second ACL injury, in either knee, so prevention matters.

When Should You See a Knee Specialist?

• A pop during a twisting injury followed by swelling
• A knee that gives way or feels unstable
• Difficulty fully straightening or bending the knee
• Persistent pain or swelling after a knee injury
• A knee that locks or catches, which suggests an associated meniscus tear

Early assessment lets us diagnose the injury properly, protect the knee from further damage and plan treatment. Delays and repeated giving way can lead to meniscus and cartilage injuries.

ACL Treatment in Bengaluru: Why Choose Sports Orthopedics Institute?

Sports Orthopedics Institute is in HSR Layout, Sector 3, Bengaluru, and is led by Dr. Naveen Kumar L.V (MBBS, MS Orth, FRCS Orth, MCh Hip & Knee UK, FIFA Sports Medicine certified), a sports orthopaedic surgeon with over 27 years of clinical experience.

• Careful clinical assessment and MRI review to determine the grade and stability of your knee
• Treatment matched to your injury, sport and goals, from rehabilitation to arthroscopic reconstruction
• Treatment of associated injuries, such as meniscus tears, at the same time
• In-house rehabilitation with experienced physiotherapists and criteria-based return to sport
• Clear communication and an individualised plan for every patient
• Easy access from Koramangala, Electronic City, Sarjapur and surrounding areas

Learn more on our procedures and surgery page.

Frequently Asked Questions

What is the difference between Grade 1, 2 and 3 ACL tears?

Grade 1 is a mild sprain in which the ligament is stretched but intact. Grade 2 is a partial tear in which some fibres are torn. Grade 3 is a complete rupture. Symptoms and stability generally worsen with each grade, but treatment depends on how stable your knee is and what you need it to do, not only on the grade.

Can a Grade 2 (partial) ACL tear heal without surgery?

Many partial tears can be managed with a structured rehabilitation programme, particularly when the knee is stable and you do not play pivoting sports. A torn ligament does not heal back completely, but a stable knee with strong muscles can function well. If the knee keeps giving way, surgery may be advised.

Can a partial ACL tear become a complete tear?

Yes, it can, especially if the knee keeps giving way or you return to pivoting sport too soon. Regular follow-up and proper rehabilitation help your surgeon monitor this.

Do I need surgery for a Grade 3 ACL tear?

Not always, but it is usually recommended for young, active people and those who play pivoting sports or have recurrent giving way or an associated meniscus tear. Some lower-demand patients do well with rehabilitation. Your surgeon will discuss both options.

How accurate is MRI for ACL tears?

MRI is highly accurate for complete ACL tears and is the usual test to confirm them. It is less accurate for partial tears, so your surgeon will also rely on your examination and sometimes on arthroscopy.

How long does it take to recover from ACL surgery?

Most people are walking within a day or so and back at a desk within a few weeks. Rehabilitation takes many months, and return to pivoting sport is usually not before about 9 months, once strength and hop tests are satisfactory.

Can I play sport with an ACL tear?

Low-impact activities such as cycling and swimming are usually fine once swelling settles. Pivoting and cutting sports are risky with an unstable knee, because repeated giving way can damage the meniscus and cartilage. Ask your surgeon before returning to sport.

Will I get arthritis after an ACL tear?

The risk of knee osteoarthritis is higher after an ACL injury, whether or not you have surgery, especially with a meniscus injury. Maintaining strength, a healthy weight and following your rehab help protect the knee.

How can I prevent re-injury after ACL surgery?

Complete your full rehabilitation, pass strength and hop tests before returning to sport, continue neuromuscular and strength training, and do not rush back. Younger athletes in cutting sports are at the highest risk.

Where can I get ACL treatment in Bengaluru?

Sports Orthopedics Institute, HSR Layout, Sector 3, Bengaluru, offers assessment, treatment planning and rehabilitation for ACL injuries. Book online at sportsorthopedics.in or call +91 6364538660.

Ready to Get Your Knee Assessed?

Whatever the grade of your ACL injury, an accurate diagnosis is the first step towards the right treatment and a safe return to the sport you love. Don't wait for the knee to give way again.

Book an appointment with Dr. Naveen Kumar L.V at Sports Orthopedics Institute, HSR Layout, Bengaluru. Call +91 6364538660 or +91 9008520831, or book online at sportsorthopedics.in.

Related reading

• Horizontal vs Vertical Meniscus Tear
• Jumper's Knee (Patellar Tendinitis) Treatment in Bengaluru
• Achilles Tear Treatment in Bengaluru

References

• Benjaminse A, Gokeler A, van der Schans CP. Clinical diagnosis of an anterior cruciate ligament rupture: a meta-analysis. Journal of Orthopaedic & Sports Physical Therapy. 2006;36(5):267–288.
• Frobell RB, Roos EM, Roos HP, et al. A randomized trial of treatment for acute anterior cruciate ligament tears. New England Journal of Medicine. 2010;363:331–342.
• Ardern CL, Taylor NF, Feller JA, Webster KE. Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis. British Journal of Sports Medicine. 2014;48(21):1543–1552.
• Grindem H, Snyder-Mackler L, Moksnes H, Engebretsen L, Risberg MA. Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study. British Journal of Sports Medicine. 2016;50(13):804–808.
• Lohmander LS, Englund PM, Dahl LL, Roos EM. The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis. American Journal of Sports Medicine. 2007;35(10):1756–1769.
• Evans J, Nielson JL. Anterior Cruciate Ligament Knee Injury. StatPearls. Treasure Island (FL): StatPearls Publishing.

This article is for general information and is not a substitute for professional medical advice. Please consult a qualified orthopedic surgeon about your own condition.