ACL Injuries 101: Symptoms, Treatment and Recovery
Updated: 5 days ago
An ACL injury can happen in a split second.
You plant your foot and change direction. You land awkwardly from a jump. Or your knee twists during a fall or collision. Some people hear or feel a pop right away, followed by swelling, pain, or a sense that the knee isn’t stable.
The anterior cruciate ligament, or ACL, is one of the main ligaments that helps keep your knee stable. ACL injuries range from a sprain or partial tear to a complete tear.
Treatment isn’t based on the MRI alone. Your knee stability, activity level, other injuries, age, sport or occupation, and personal goals all help determine whether rehabilitation or ACL reconstruction may be appropriate.
At Arthritis & Sports Orthopaedics, our knee specialists provide nonsurgical and surgical treatment for ACL injuries in Sterling and South Riding, Virginia.
Key Takeaways
The ACL is one of the main ligaments that helps stabilize the knee.
ACL injuries often happen during cutting, pivoting, sudden stopping, or awkward landings.
A pop, rapid swelling, pain, and knee instability are common symptoms.
Not every ACL tear requires surgery.
Physical therapy plays an important role in both nonsurgical treatment and recovery after ACL reconstruction.
Surgery may be considered when the knee remains unstable or when someone wants to return to activities that place greater demands on knee stability.
Returning to sports should be based on strength, stability, movement quality, confidence, and sport-specific testing—not the calendar alone.
What Is the ACL?
The ACL is a strong band of tissue inside the knee that connects the thighbone to the shinbone.
It helps control forward and rotational movement of the knee and provides stability during activities such as running, cutting, pivoting, and changing direction.
An ACL injury can range in severity.
A mild injury may stretch the ligament without completely tearing it. Other injuries involve a partial tear or a complete tear.
The severity of the tear is important, but it’s only part of the picture. How stable the knee feels and what you want to return to doing also matter.
How Do ACL Injuries Happen?
Many ACL injuries happen without anyone hitting the knee.
A sudden stop, quick change in direction, pivot, or awkward landing can place enough force on the ligament to injure it.
ACL injuries are common in sports that involve frequent changes of direction, including:
Soccer
Basketball
Football
Lacrosse
Skiing
Volleyball
But you don’t have to be a competitive athlete to tear your ACL. The ligament can also be injured during recreational activities, falls, or other accidents.
Sometimes the ACL isn’t the only structure damaged.
The same twisting or pivoting force can also injure the meniscus, cartilage, or another ligament inside the knee.
If you’re trying to understand which structure may have been injured, read our guide to ACL tear vs. meniscus tear symptoms, treatment, and recovery.
Who Is at Risk for an ACL Injury?
Anyone can tear an ACL, but the risk is higher during sports and activities that involve frequent:
Cutting
Pivoting
Jumping
Sudden stopping
Changes in direction
Female athletes have higher ACL injury rates than male athletes in several comparable sports.
There isn’t one single reason for that difference. Researchers have looked at a combination of factors involving anatomy, biomechanics, muscle control, landing mechanics, and other influences.
Training can make a difference.
Neuromuscular programs that focus on strength, balance, landing technique, body control, and cutting mechanics may help reduce the risk of ACL injuries in athletes.
What Does an ACL Tear Feel Like?
ACL symptoms can vary, but many people know something significant happened right away.
Some hear or feel a pop when the injury occurs.
Common symptoms may include:
Knee pain
Swelling that develops fairly quickly
Loss of knee motion
Difficulty putting weight on the leg at first
A feeling that the knee is unstable
Buckling or giving way
As the first wave of pain and swelling improves, instability may become more noticeable.
You might be able to walk comfortably in a straight line but feel that the knee can’t be trusted when you turn, pivot, or change direction.
That feeling of instability is one of the important factors your orthopedic specialist will consider during an evaluation.
How Is an ACL Injury Diagnosed?
Diagnosing an ACL injury starts with understanding what happened.
Your orthopedic specialist may ask:
What were you doing when the injury occurred?
Did you hear or feel a pop?
How quickly did your knee swell?
Were you able to continue the activity?
Does the knee feel unstable?
Has it buckled or given way?
Can you fully bend and straighten your knee?
The next step is a physical examination.
Your provider may check:
Swelling
Range of motion
Areas of tenderness
Knee stability
Strength
How the knee responds to specific movements
Orthopedic specialists can also use specific examination techniques to test the stability of the ACL.
No single finding tells the whole story. Your symptoms, examination, and imaging—when needed—are considered together.
Do You Need an MRI for an ACL Tear?
Not every knee injury automatically needs an MRI.
Your injury history and physical examination often provide important information first.
An MRI may be recommended to get a detailed look at the ACL and other soft tissues inside the knee. It can also help identify injuries to the meniscus, cartilage, or other ligaments that may have happened at the same time.
What Do Knee X-Rays Show?
An X-ray can’t directly show a torn ACL.
It may still be useful for checking for:
Fractures
Arthritis
Bone abnormalities
Other changes within the joint
Your provider will decide which imaging is appropriate based on your injury.
Does Every ACL Tear Need Surgery?
No.
An ACL tear does not automatically mean you need an operation.
Some people can function well with rehabilitation, particularly if the knee becomes stable enough for the activities they want to do.
Nonsurgical treatment may include:
Strengthening
Improving knee motion
Swelling management
Balance and stability training
Activity changes when appropriate
Bracing in selected situations
The right treatment depends heavily on the individual.
For example, someone who mainly walks, cycles, swims, or exercises in a straight line may place very different demands on the ACL than an athlete trying to return to soccer, basketball, football, or another cutting sport.
When Is ACL Surgery Considered?
ACL reconstruction may be considered when the knee continues to feel unstable or when a patient wants to return to activities that require cutting, pivoting, and rapid changes in direction.
Other injuries inside the knee can also affect the decision.
Your orthopedic surgeon may consider:
Whether the ACL is partially or completely torn
How unstable the knee feels
Meniscus or cartilage injuries
Your age
Your activity level
Your sport
Your occupation
Previous knee injuries
Your personal goals
There isn’t one treatment plan that works for everyone.
Dr. Matthew Griffith, orthopedic sports medicine surgeon, states: “An ACL tear isn’t treated based on the MRI alone. We look at how stable the knee is, whether other structures were injured, and what the patient wants to get back to doing before deciding whether surgery makes sense.”
What Happens During ACL Reconstruction?
When surgery is appropriate, ACL reconstruction is commonly used to restore stability to the knee.
During reconstruction, the damaged ACL is replaced with a graft.
Depending on the patient and surgeon’s recommendation, the graft may come from tissue such as the:
Patellar tendon
Hamstring tendon
Quadriceps tendon
Other graft options may be considered in certain situations.
There isn’t one graft that is automatically best for every person.
Your surgeon will consider factors such as your age, activity level, sport, anatomy, and the advantages and disadvantages of each option.
If the meniscus, cartilage, or another ligament was injured at the same time, those problems may also need to be addressed.
Learn more about our approach to sports medicine.
How Long Is Recovery After ACL Reconstruction?
ACL reconstruction is only the beginning of the recovery process.
Rehabilitation takes many months and progresses gradually.
Early recovery usually focuses on:
Controlling swelling
Restoring knee motion
Regaining muscle control
Walking safely
As the knee improves, physical therapy progresses toward more demanding activities.
That may include:
Strength training
Balance
Running
Jumping
Cutting
Agility
Sport-specific movements
When Can You Return to Sports After ACL Surgery?
There isn’t one date that applies to everyone.
Returning to sports shouldn’t be based only on how many months have passed since surgery.
Your surgeon and physical therapist may consider:
Knee stability
Strength
Range of motion
Swelling
Movement quality
Balance and control
Sport-specific testing
Confidence in the knee
The sport matters, too.
Returning to straight-line jogging is very different from returning to soccer, basketball, football, lacrosse, or another activity that requires frequent cutting and pivoting.
Recovery may also take longer or involve different restrictions when another injury—such as a meniscus repair—is treated at the same time.
Can ACL Injuries Be Prevented?
No training program can prevent every ACL injury.
Certain types of training, however, may lower the risk.
Neuromuscular injury-prevention programs often focus on:
Proper landing technique
Strength
Balance
Agility
Cutting and pivoting mechanics
Body control
Coordination
These programs can be especially helpful when they’re built into regular sports training instead of being used only after an injury occurs.
Coaches, athletic trainers, physical therapists, and sports medicine professionals can all play a role in teaching safer movement patterns.
ACL Treatment in Sterling and South Riding, VA
Arthritis & Sports Orthopaedics provides sports medicine and knee care for ACL injuries throughout Loudoun County and Northern Virginia.
ACL and Knee Care in Sterling, VA
Matthew H. Griffith, MD is a board-certified orthopedic surgeon with fellowship training in sports medicine and shoulder surgery.
Dr. Griffith treats athletic and traumatic knee injuries, including ACL and other ligament injuries, meniscus tears, and conditions that may require knee arthroscopy.
He sees patients at our Sterling, Virginia office.
ACL and Knee Care in South Riding, VA
David S. Goodwin, MD is a board-certified orthopedic surgeon with fellowship training in sports medicine.
Dr. Goodwin provides nonsurgical and surgical treatment for knee and sports injuries, including ligament, meniscus, and cartilage conditions.
He sees patients at our South Riding, Virginia office.
Treatment is tailored to the injury, knee stability, activity level, and goals of each patient.
Get the Right Diagnosis for Your Knee Injury
A pop, swelling, or instability can tell you that something is wrong, but those symptoms don’t tell you exactly what was injured.
An orthopedic evaluation can help determine whether the ACL or another structure inside the knee has been damaged and which treatment options make the most sense for you.
If your knee is swollen, unstable, repeatedly giving way, or keeping you from the activities you enjoy, request an appointment with an Arthritis & Sports Orthopaedics knee specialist in Sterling or South Riding, VA.
Frequently Asked Questions About ACL Injuries
Can You Walk With a Torn ACL?
Yes. Many people can walk with a torn ACL, particularly after the initial pain and swelling begin to improve. Being able to walk doesn’t mean the ACL is intact. Instability may become much more noticeable when you turn, pivot, cut, or perform activities that place greater demands on the knee.
Does Every ACL Tear Need Surgery?
No. Some ACL injuries can be treated without surgery, especially when the knee becomes stable enough for the patient’s usual activities. ACL reconstruction may be considered when instability continues, other parts of the knee are injured, or the patient wants to return to sports or activities that require frequent cutting and pivoting.
Can an ACL Tear Heal Without Surgery?
Some people with ACL injuries can function well without surgery through rehabilitation and activity modification. Whether nonsurgical treatment is appropriate depends on the severity of the injury, knee stability, other damage inside the knee, activity demands, and personal goals. Your orthopedic specialist can help determine which approach makes sense for you.
Do You Need an MRI for an ACL Tear?
Not always. An orthopedic provider can often learn a great deal from the way the injury happened and from the physical examination. An MRI may be used to confirm the ACL injury, assess the tear, or look for associated damage to the meniscus, cartilage, or other ligaments.
How Long Does It Take to Recover From ACL Reconstruction?
Recovery after ACL reconstruction usually takes many months, but the timeline varies from person to person. Returning to sports should be based on more than time alone. Strength, knee stability, movement quality, range of motion, confidence, and sport-specific testing can all play a role in determining when it’s safe to return.
