A person wearing workout clothes sitting down outside holding their knee.

Pain and Swelling in Your Knee? It Could Be a Torn Meniscus

Lateral Meniscus Tear: Symptoms and Treatments

Each knee has two pieces of cartilage that serve as stabilizers and shock-absorbers between your thigh bone (femur) and shin bone (tibia). These C-shaped pieces of cartilage are called the menisci. The cartilage on the inner side of the knee is called the medial meniscus, and the one located on the outside of the knee is named the lateral meniscus. For some people, a lateral meniscus tear can occur.

The meniscus can be damaged and torn. A lateral meniscus tear can vary widely in severity. Most injuries on the meniscus are caused by pressure or sudden rotation of the knee while the foot is planted on the ground. A meniscus tear can also develop slowly as the cartilage loses its flexibility.

A torn lateral meniscus is an injury to the semi-circular cartilage on the outer side of the knee joint. It causes pain, swelling and stiffness on the affected knee. You may also have difficulty fully extending your knee or experience a block to knee motion.


Symptoms of a lateral meniscus tear will differ depending on whether it developed suddenly (acute) due to direct impact, twisting, or trauma, or if the injury happened gradually (chronic) through wear and tear.

Acute Lateral Meniscus Tear

Acute lateral meniscus tears occur suddenly, and symptoms are experienced right after the time of injury. Symptoms may include the following:

  • Sudden pain on the outer aspect of the knee at the time of injury. Walking and weight-bearing activities may exacerbate the pain on the affected knee.
  • There will be tenderness on the outside surface of the knee when pressing it, especially on the joint line.
  • Swelling will be apparent on the knee right after the injury or may happen within 24 to 48 hours after the incident.

Chronic Lateral Meniscus Tear

Chronic lateral meniscus injuries develop gradually. You will not be able to identify when the injury occurred because it happened slowly, due to wear and tear of the cartilage. Chronic meniscus tears may be difficult to diagnose because the pain will be vague and difficult to localize. Symptoms of a chronic lateral meniscus tear may include:

  • Swelling, pain and tenderness on the joint line on the outer side of your knee. These may worsen in activities that involve twisting or rotating your knee, or less commonly during squatting or bending the knee.
  • Sensation of locking of the knee in place when you try to move it.
  • Feeling of the affected knee giving way.
  • A popping, snapping, or clicking sound might be heard when bending the affected knee.

Treatment Options for Lateral Meniscus Tear

Treatment for meniscus injuries usually start conservatively, meaning no surgery is needed unless the extent of damage on the cartilage is severe, or if the injury limits your ability to walk and be mobile.

Conservative treatment may be one or more of the following:

  • Cold therapy. If your knee is swelling, you should apply the RICE (rest, ice, compression, elevation) therapy. Cold compresses can be applied on the affected area for 10 to 15 minutes every two hours initially and the frequency may be reduced as the symptoms improve.
  • Knee supports and braces. Knee supports may help protect the joint while the knee is healing.
  • Rehabilitation exercises. These exercises are usually given by a physiotherapist to help you with the proper muscle strengthening, mobility exercises and guidance on the proper return to activity and sport to let the cartilage have the best recovery prior to the application of stress.
  • Supplementation. Glucosamine supplements may help with the cartilage-healing process.
    Non-conservative treatment will involve surgery. This usually is the last option after other measures have been attempted.

What Causes a Meniscus Tear?

An acute torn meniscus may be caused by direct impact or any activity that causes you to have sudden twisting or rotating movements on the knee. These movements are usually encountered in sports, such as basketball or football, which involve aggressive pivoting or sudden stops and turns. Although less common, kneeling, deep squatting and heavy lifting with bad technique can sometimes cause a torn meniscus.

Chronic lateral meniscus tears usually are caused by degenerative changes on the cartilage which decreases the resiliency of the menisci. Osteoarthritis and excess weight bearing, such as in obesity, may also be factors contributing to the wear and tear of the cartilage, which may lead to the loss of integrity of the menisci.

The Diagnosis Process

Diagnosing a lateral meniscus tear will involve a complete knee assessment by a doctor. Specific maneuvers will be done on the knee to determine the cause of the injury. Some examples of these maneuvers are the Apley’s and McMurrays’s tests.

An ultrasound or an MRI may be needed to confirm the diagnosis and determine the extent of damage on the structures. This may also guide the doctor on the treatment plan that you may need.

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