If you have unexplained knee pain, swelling or instability, you may be wondering if you have a meniscus tear. We’ll guide you through the common symptoms of a meniscus tear, what a meniscus tear MRI can show, and how it is carried out.

We’ll also describe the different types of meniscus tears that can happen and what treatment your clinician will likely recommend if they find out you have a tear in the meniscus.

What is the meniscus?

The meniscus is a C-shaped piece of cartilage in your knee joint that acts like a cushion between your thighbone (femur) and your shinbone (tibia). You have two menisci in each knee - the lateral meniscus on the outer and the medial meniscus on the inner side.

These menisci are really important for proper knee function and joint health. They act like shock absorbers, taking on much of the pressure and force that goes through your knees when you walk, run or jump. They help to stabilise the joint and enable it to move smoothly.

What is a meniscus tear?

A torn meniscus is a common injury to the knee cartilage, especially if you’re very active or athletic. Meniscus tears can happen with sudden twisting or rotating of the knee joint, overuse from repetitive activities, or degenerative changes that come along with ageing.

There are six different types of meniscus tears, and each one gets its name from the pattern of damage experts can see on the meniscus itself:

Radial meniscus tear: Develops along the curve of the meniscus.
Intrasubstance meniscus tear: Develops within the meniscus without extending to the edges.
Horizontal meniscus tear: Runs horizontally across the meniscus.
Complex meniscus tear: Involves multiple tears, such as radial and horizontal tears.
Bucket handle meniscus tear: A portion of the meniscus displaces into the joint, making it look like a bucket handle.
Flap meniscus tear: A flap of the meniscus tissue detaches partially or entirely from the main body.

While younger people are more likely to experience acute meniscus tears through exercise or injury, older people are more likely to have a variety of tears and fragmentation due to the meniscus weakening with age.

What are the main symptoms of a meniscus tear?

If you’ve damaged the meniscal tissue in your knee, you may experience:

Pain, especially when touching your knee
Swelling
Difficulty achieving a full range of motion (such as when bending, straightening or twisting) in the knee when walking, moving or exercising
An uncomfortable feeling of knee locking or catching within the joint
Feeling like your knee is weak or going to give way when you move, stand or put weight on it

Diagnosing meniscus tears

To diagnose a meniscus tear, you’re likely to have a combination of the following tests:

Physical Examination - Your doctor will feel around your knee while it's at rest and during gentle movement.
McMurray Test - They may rotate and extend your knee and check for clicking or knee locking, tell-tale signs of a meniscus tear, while you’re lying down.
Thessaly Test - Your doctor may also perform the same tests while you're standing on one leg, holding onto a bar for balance.
Apley Compression Test - Your doctor may also rotate your leg while applying pressure on your ankle while you’re lying face down with your leg bent.
Initial Imaging (X-Ray) - An X-ray is sometimes used to provide an initial view of the knee bones, looking for fractures (specifically, subchondral insufficiency fractures, small weaknesses in the bones beneath the cartilage) and other abnormalities.
MRI Scan - A knee MRI is used to take a detailed look at the structures within the knee, including the anterior root and posterior root (the fibrous pieces of tissue that connect the meniscus to the tibial plateau, or top of the shin bone, and the other articular surfaces, or tops of the bones, to allow for smooth movement).
Differential Diagnosis Review - Your MRI results are used to diagnose a different condition if a meniscus tear is ruled out.
Specialist Referral (Orthopaedics) - If you require meniscal surgery, you’ll be referred to a specialist orthopaedic surgeon.

When should I get a meniscus tear MRI?

It may be a good idea to have an MRI for a meniscus tear if you experience certain symptoms in the knee, including:

Pain.
Swelling.
Tenderness.
Stiffness.
A sensation of the knee ‘catching’ or ‘locking’, which may feel a bit crunchy or clicky.
A feeling of instability or ‘giving way’ in the knee.
Difficulty bending, straightening or moving the knee.

If you tore your meniscus in an injury, you may also have felt a ‘pop’ in the knee.

Some small meniscus tears can heal on their own but many cannot, so it’s essential to get the correct diagnosis and treatment to help relieve your symptoms and prevent further damage.

Types of MRI for a meniscus tear

Various MRI scans are used to diagnose meniscal injuries. Which one you have will depend on your symptoms, medical history and current health.

Standard Knee MRI - You may be moved into different positions to scan your knee from the side to produce sagittal images, and from the front and back of the knee, during a standard knee MRI.
High-Field MRI - A faster MRI that produces superior images of very small tears and abnormalities.
Open MRI - Similar to a standard MRI, performed on a newer-style open MRI machine and ideal for claustrophobic patients.
MR Arthrography - An MRI scan that uses a contrast dye to better highlight cartilage and ligaments, often used to plan and guide surgery.
Proton Density MRI Sequences - A specialised MRI that further differentiates between fatty tissue, fluids and types of cartilage.
T2-Weighted MRI Sequences - Similar to a standard MRI, with a different signal intensity to highlight the joint fluid.
Fat-Suppressed MRI Sequences - A specialised MRI that removes the signal from the fatty tissue in the knee to further expose the cartilage and ligaments on the MRI images.

How an MRI scan detects a meniscus tear

An MRI scanner uses radio waves and a strong magnetic field to create detailed images of the bones and soft tissues within a joint, such as the knee. During an MRI scan, hydrogen atoms in the body are temporarily disrupted and then realigned. As this happens, the hydrogen atoms generate energy that MRI computers detect and convert into an image.

A trained medical professional, called a radiographer, interprets these images and can detect abnormalities such as a meniscus tear, leaking synovial fluid (the liquid that lubricates and cushions the knee) and displaced meniscus fragments.

What will happen at the scan?

The MRI machine uses powerful magnetic fields and radio waves to create detailed cross-sectional images of your knee joint and surrounding soft tissues, including the menisci. It’s noninvasive and doesn’t involve radiation exposure. You'll need to remain perfectly still during the imaging process, which usually takes 20 to 40 minutes.

Before the MRI scan, your technician will ask you to remove any metal objects, jewellery, or clothing with metal zippers or fastenings. These can interfere with the magnetic field used in the MRI machine.

You'll lie flat on your back on the MRI table, with your knee positioned in a specialised device or coil that helps produce clear images of the knee joint.

In some cases, your technician may inject a contrast agent into a vein in your arm, which can help to enhance the visibility of the inside of the knee. This isn’t usually required, but we’ll let you know in advance of your scan if it is.

What does a meniscus tear look like on an MRI?

Normal knee MRI: A normal knee shows the meniscus as a smooth, crescent-shaped structure with no breaks or tears. It is dark grey or black, and the outer edge is sharp and clear.
Abnormal knee MRI: An abnormal knee MRI will identify any issues with the meniscus. On MRI pictures of meniscus tears, a torn meniscus will look disrupted or abnormal. You may see bright, white vertical or horizontal lines through the menicus, or multiple irregular lines if you have a complex meniscal tear. Radial tears may extend from the centre towards the edge of the meniscus.

There may also be a build-up of fluid within or around the meniscus, which appears bright white or light grey.

What are my next steps if my MRI scan shows a meniscus tear?

If your MRI identifies a meniscus tear, several treatments are available, depending on the type and size of the tear, your age, your overall health, and how severe the tear is (grade 1, 2 or 3). Your clinician may refer you to an acute knee clinic for further tests and treatment.

Grade 1 or 2 meniscus tears usually require painkillers and physiotherapy. Grade 3 meniscus tear MRI results usually require physiotherapy, painkillers and a surgical procedure.

Medicines

Your clinician may recommend over-the-counter painkillers, such as paracetamol or ibuprofen, to help relieve your knee pain. Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID) that can help reduce inflammation and swelling.

If you are experiencing severe knee pain, your doctor may prescribe stronger painkillers.

Physiotherapy

Your clinician will recommend physiotherapy to help strengthen the knee joint and improve the mobility of your knee. You’ll have a specific set of exercises to do every day, sometimes multiple times a day.

It’s important to do these exercises as recommended alongside any other treatment, such as surgery, as they can help with the rehabilitation process.

You can also swim, cycle, walk or try other low-impact exercises that help to improve knee stability without causing pain.

Surgery

Your clinician may recommend surgery if you have a complex or severe meniscal tear, or if physiotherapy has not resolved the problem.

A surgeon will carry out an operation called a knee arthroscopy, which is a type of keyhole surgery. During the surgery, they may trim or repair the torn meniscus or remove the damaged section of the meniscus.

In some cases, such as older people with complex tears, the meniscus may be removed completely. You’ll also need physiotherapy for at least six weeks after the surgery.

Causes of meniscus tears

In younger people, a meniscus tear is generally caused by injury to the knee during sports, particularly those that involve twisting, pivoting and sudden start-stop motions, such as football, netball, basketball and tennis. They can also be caused by repeatedly lifting heavy objects.

Meniscus injuries in older people are often caused by age-related wear and tear of the knee.

Prognosis and treatment

Treatment for a meniscus tear will depend on the severity of the tear and your overall health and fitness. You may need painkillers, physiotherapy, meniscal surgery or a combination of two or more treatments.

Surgery usually involves either a meniscal repair when the torn pieces of cartilage are sewn back together, or a partial meniscectomy, when the damaged cartilage is trimmed away. Such knee surgery is usually carried out as keyhole surgery, performed through small incisions in the knee while you're under a general anaesthetic.

With a proper diagnosis and timely treatment, you can return to full function and mobility of the knee joint.

How long does a meniscus tear take to heal?

Recovering from a meniscus tear can take time and patience. How long it takes to heal depends on several key factors.

Minor, stable tears may only need rest, ice, compression, and elevation (RICE), physical therapy exercises and medication for pain and swelling. The knee may improve in four to eight weeks, but it can take up to three months or longer depending on your age and physical health.

If the tear is more serious and requires surgery, you may need crutches and physiotherapy for around four to six weeks. Getting back to normal activities could take up to six months as you regain strength and flexibility.

If you're older or you have a degenerative condition, part or all of the damaged meniscus may need to be removed. Recovery can take up to four weeks, but you’ll need to adapt to the loss of the meniscus. This can take several months as your knee joint gets used to not having that shock absorber in place.

Dealing with a meniscus tear can be painful and frustrating, but an MRI can help to diagnose the injury quicker so you can get the right treatment - whether that’s rehabilitation through physiotherapy, or surgery. You can skip the NHS waiting lists and book a knee MRI with Scan.com at a time and place that’s convenient to you, so you can start to regain your mobility and strength.

Find an MRI scan for a meniscus tear

Get a meniscal injury diagnosed quickly with a private MRI scan of the knee. With over 250 scanning centres to choose from, and no need for a GP referral, Scan.com will help you get a diagnosis sooner so that you can start treatment and get back to health as soon as possible.

FAQs

Is an MRI safe?

Yes, an MRI scan is a safe procedure for most people. You may not be suitable for an MRI scan if you have metal inside your body (including implants, shards, shrapnel and bullets). Speak to your medical team if you’re concerned.

How accurate is an MRI for diagnosing a meniscus tear?

MRI scans are extremely useful for diagnosing a torn meniscus, including medial and lateral meniscus tears, as well as other knee injuries and conditions, such as ACL tears, tears of the medial collateral ligament or the fibular collateral ligament and degenerative arthritis.

How long does a knee MRI take for a meniscus tear?

An MRI scan for a meniscus tear takes between 20 and 40 minutes.

Is a meniscus tear MRI scan painful?

No, you won’t feel anything during an MRI scan of the knee.

Sources:

Bhan, K. (2020). Meniscal Tears: Current Understanding, Diagnosis, and Management. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7359983/

Kim, SH, et al. (2021). Diagnostic Accuracy of Magnetic Resonance Imaging in the Detection of Type and Location of Meniscus Tears: Comparison with Arthroscopic Findings. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914628/

Medial and Lateral Meniscus Tears. (N.D.) https://www.cedars-sinai.org/health-library/diseases-and-conditions/m/medial-and-lateral-meniscus-tears.html

Meniscus tear. (2023). https://www.bupa.co.uk/health-information/knee-pain/meniscal-tear

Torn meniscus. (2022). https://www.mayoclinic.org/diseases-conditions/torn-meniscus/diagnosis-treatment/drc-20354823