What is the Thessaly test?
The Thessaly test is a series of knee and leg movements healthcare providers use to diagnose a torn meniscus. It’s an in-office physical exam, which means your provider can perform it without any special equipment or a separate appointment.
You will stand on one leg and twist side-to-side to identify any pain or other symptoms you feel during the movements.
The Thessaly test is usually part of a preliminary exam when you visit your provider with knee pain or after an injury. You’ll probably also need at least one of a few imaging tests to confirm a torn meniscus or any other injuries in your knee.
When would I need the Thessaly test?
Your provider will perform the Thessaly test if they think you have a torn meniscus. It’s one of the most common knee injuries — especially among athletes.
Your meniscus is a rubbery wedge of cartilage in your knee between your femur (thigh bone) and tibia (shin bone). It’s like a shock absorber that cushions your bones and knee joints. Any sudden and intense jerking motion on your knee can tear your meniscus. Sports injuries are the most common cause, but traumas like falls and car accidents can also tear your meniscus.
The most common symptoms of a torn meniscus include:
- Feeling or hearing a pop in your knee.
- Instability in your knee or feeling like it might give out.
- Being unable to fully bend or straighten your knee like you usually can.
You might need a Thessaly test when you visit your provider after injuring your knee. They’ll perform the test as part of your physical exam, especially if you’re having symptoms of a torn meniscus. The Thessaly test can help your provider know if you damaged your knee ligaments or other connective tissue during your injury.
People who have torn their meniscus have an increased risk of developing osteoarthritis of the knee.
Who performs the Thessaly test?
Your provider will perform the Thessaly test in their office. They don’t need any special equipment or facilities to conduct the test.
How does the Thessaly test work?
The Thessaly test is a series of movements to check your symptoms and range of motion (how far you can move your knee joint). The test is simple and includes the following steps:
- You’ll stand on one leg with your foot flat on the ground.
- Your provider will support you by your arms.
- You’ll twist the knee on your standing leg in (toward your body) and out (away from your body) three times in a row.
- Your provider might perform the test twice — once with your knee barely bent, and once with a deeper bend.
Your provider might have you do a Thessaly test on both legs, starting with your uninjured leg. This will help you understand the test’s motions and positions before doing it on your injured leg. It will also help them know your baseline range of motion.
The Thessaly test’s movements apply mild stress to your meniscus. They’re close to the kind of tension that’s applied to your knee while you use it throughout a typical day.
While you’re moving throughout the test, your provider will ask you if you’re feeling any pain or if your knee feels like it’s sticking or locking. They’ll also listen for a popping in your knee. This lets them check for where (or how severely) your meniscus might be torn.
Thessaly test vs McMurray test
Both the Thessaly test and the McMurray test are physical motions that can help your provider diagnose a torn meniscus in your knee. The difference is which specific movements you perform.
During a Thessaly test, you’ll stand on one leg with and turn side-to-side while your provider supports your arms.
If you need a McMurray test, you’ll lie on your back while your provider bends and moves your knee.
In both tests, your provider is feeling and listening for symptoms of a torn meniscus in your knee. Make sure you tell them if you feel any pain or discomfort.
How do I prepare for a Thessaly test?
You don’t need to do anything to prepare for a Thessaly test. Just visit your provider as soon as possible if you’ve injured your knee or you notice any new symptoms.
What should I expect during a Thessaly test?
Try to relax during the Thessaly test and do the movements as best as you can.
Because the Thessaly test is a series of physical motions, tell your provider everything you’re feeling — especially if any of the movements hurt or make you uncomfortable.
Any pain, discomfort or other symptoms you feel during a Thessaly test will help your provider know where your meniscus is torn, or what other kind of injury you might have.
What should I expect after a Thessaly test?
A Thessaly test is usually a first step in treating your knee. Your provider will probably recommend some imaging tests to diagnose an injury in your knee.
These tests will take pictures of the inside of your knee and confirm any damage inside your joint. The most common imaging tests include:
Your provider will tell you which imaging tests you’ll need and which injuries they’re looking for.
You might also need a knee arthroscopy to diagnose or repair damage inside your knee. Knee arthroscopy is a minimally invasive surgical procedure that lets your surgeon see inside your knee joint with a tiny camera. Most knee arthroscopies are outpatient procedures, meaning you can go home the same day.
Does the Thessaly test have any risks?
There are no risks to performing a Thessaly test.
You might feel a little pain or discomfort during the test, but even if your meniscus is torn, you shouldn’t feel intense pain.
Some studies have shown that even though the Thessaly test is more accurate at proving whether or not your meniscus is torn than other similar exams, it’s not perfect. However, it’s usually only the first step your provider will take to diagnose your injury. Imaging tests will give a more conclusive answer, which is why you’ll probably need at least one after your Thessaly test.
Results and Follow-Up
What type of results will I get and what do they mean?
The Thessaly test’s results aren’t as direct as some other tests you might have had before. Instead of giving an exact range or a specific number, a Thessaly test gives your provider a better understanding of what might be injured in your knee.
It’s more like a true or false question and less like a math problem that gives an exact answer. Your provider will classify your test as positive if they find anything that indicates that your meniscus is torn. A negative result means you didn’t experience pain, discomfort or other symptoms during the test.
A negative result doesn’t necessarily mean you won’t need other tests. Your meniscus might still be torn, or there might be other damage inside your knee.
When should I call my doctor?
Visit your provider if you’re experiencing symptoms like pain or swelling that get worse after a few days.
Go to the emergency room right away if you notice any of the following:
- Extreme pain.
- Swelling that’s getting worse.
- You can’t move your knee at all or can’t move it like you usually can.
A note from Cleveland Clinic
A Thessaly test can be a quick way for your provider to diagnose a meniscus tear in your knee. Even though it’s not conclusive and you’ll probably still need at least one imaging test afterward, it’s a good starting point to know what’s causing you pain or discomfort. Let your provider know anything you’re feeling during the test. Even small changes in your pain or a stuck sensation can be a clue to what’s damaged inside your knee.
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