Can you tear your ACL without knowing? (2023)

Home » Can you tear your ACL without knowing? (2023)

Can you tear your ACL without knowing?

It is possible to tear your ACL without knowing, as pain is not always present after a tear occurs. However, generally, your knee will feel unstable or give way/buckle after an ACL injury and show some signs of swelling.

The anterior cruciate ligament (ACL) is a key stabilizing ligament located in the knee. It helps to prevent the knee from hyperextending and provides stability when pivoting or changing direction.

The anterior cruciate ligament’s main action is to prevent the shin bone from moving too far forward from the thigh bone (femur).

A torn ACL can occur due to a sudden twisting motion, direct impact to the knee, or landing awkwardly from a jump.

image of a normal acl and a torn acl
A visual of a normal ACL and an ACL full tear

So yes, you may have a minor tear in the ACL or an ACL sprain, and feel completely fine.

If you’ve just had an injury and suspect this, seek out a knee function test with a physical therapist or sports medicine doctor. They will assess your knee integrity and stability, and tell you if you should be walking on it.

They will want to perform tests on your meniscus, ACL, PCL, and collateral ligaments.

therapist performing a knee test.
A doctor checks for ligament and meniscus knee injury.

The ACL Scenario

If you suffer a sudden, severe injury to your knee, you may have a complete ACL rupture. This can happen if the force of the direct blow is strong enough to overcome the ligament tension.

In some cases, people may only realize they have torn their ACL when they experience pain and swelling in the joint several hours after the initial injury occurred, but most likely the pain is sudden, severe, and makes it hard to even walk.

image of a woman alpine ski racing
Skiing is a common cause of ACL injury

A key characteristic of an ACL tear is a “popping” sound. Early diagnosis and treatment can help reduce the risk of further damage to the knee joint.

You don’t want to jump right back on the basketball court after an injury like this!

ACL injuries can often be mistaken for other types of knee injuries, such as meniscus tears or patellar subluxation.

Meniscus Tear Symptoms

  • A popping or clicking sound when the knee is bent and straightened
  • Sudden, sharp pain in the knee
  • Pain that increases with activity
  • Swelling, or possibly no swelling in the knee
  • Difficulty moving the knee

Patellar Subluxation Symptoms

  • A popping or snapping sensation in the knee
  • Sudden, sharp pain in the knee
  • Pain that increases with activity
  • Swelling and stiffness in the knee
  • Instability in the knee joint
image showing a normal vs. a displaced patella
a normal vs. displaced patella

Anterior Cruciate Ligament Surgery

If you have suffered a complete tear of your ACL, surgery will be necessary to have an orthopedic surgeon repair the damage.

The most common type of ACL surgery is known as anterior cruciate ligament reconstruction.

This procedure involves taking a piece of tissue from another part of your body, such as the patellar tendon or the hamstring tendon, and using it to create a new ACL.

The new ACL will be attached to your knee using screws and other fixation devices.

image showing screws used in ACL repair
screws are often used in ACL surgical repair

Recovery from ACL surgery can take several months. During this time, it is important to follow your doctor’s instructions for physical therapy and knee exercises. You may also need to use crutches or a knee brace to help keep your knee stable as it heals.

Partial ACL tears

If you have suffered a partial tear of your ACL, surgery may or may not be necessary. In some cases, the knee joint can be stabilized using ice, anti-inflammatory medications and rest, a knee brace, and TENS therapy.

However, if the knee joint is still unstable, surgery may be necessary to repair the damage.

The type of surgery will depend on the extent of the damage.

Many people, especially non-athletes, do just fine with an appropriate leg strength training program and no surgical intervention.

Can my ACL tear lead to Arthritis?

People who experience an ACL injury have a higher risk of developing osteoarthritis in the knee [].

So be aware, even though surgery may be recommended, it is no guarantee that you won’t develop OA in the future.

In conclusion, it is possible to tear your ACL without knowing, but it would be a very minor tear to have no symptoms. It is also possible to take precautions to avoid ACL injuries in the first place!

If you think you may have suffered an ACL injury, it’s important to see a doctor so that they can confirm the diagnosis and recommend treatment.

MRI is the best technique to image this. Early diagnosis and treatment can help reduce the risk of further damage to the knee joint. Read here for a guide to MRI costs.

Home » Can you tear your ACL without knowing? (2023)

Author Bio

Dr Jason Whealing headshot

Dr. Jason Whealing is a Chiropractor with extensive experience across the UK and Australia. He is passionate about family care and injury management. The cases Jason works with daily include back pain, neck pain, jaw pain, sciatica, knee pain, shoulder pain, headaches and migraine.

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