An overview of meniscus tears: Symptoms, causes, and treatment options
An overview of the knee and meniscus
The knee structure and function
The knee joint is formed by the thigh bone (femur) at the top, the shinbone (tibia) at the bottom and your kneecap (patella) in the front. It’s a hinge joint that bends and straightens your leg and helps balance out the forces from your feet.
Slippery cartilage covers the surfaces of the knee joints – keeping the bones cushioned and gliding smoothly over each other, preventing friction and wear and tear.
What is a meniscus and why is it important?
A meniscus is a c-shaped, wedged disc of rubbery cartilage attached to the flat surface of the shinbone. There are two menisci in each knee, one on the inner side (medial meniscus) and one on the outer side (lateral meniscus).
Menisci act as little shock absorbers and help with weight distribution in the knee. They also improve knee stability and proprioception (body position sense).
What are the main muscles around the knee?
The quadriceps muscles (front of thigh) straighten the knee, and the hamstring muscles (back of thigh) bend the knee. They also protect it from being forced into unsafe positions during movement.
What do the ligaments in the knee do?
Knee ligaments help stabilize the joint. The medial and lateral collateral ligaments (MCL and LCL) on the inner and outer sides of the knee joint keep it from moving too far out to the sides.
The anterior and posterior cruciate ligaments (ACL and PCL) in the core of the knee joint stop it from over-bending and over-straightening.
Symptoms of meniscal tears
Symptoms of a torn meniscus can range from mild to severe and may come on quickly or take a few days to develop.
What does it feel like when you tear a meniscus?
Sometimes, a meniscal tear is felt as a sharp twinge of pain inside the knee, which then subsides and disappears, and you only start noticing pain again a few days later.
Other times, the pain is felt immediately and the symptoms continue to build up over a shorter period of time. Common symptoms are:
- Pain along the knee joint line
- Puffiness or swelling around the knee
- Stiffness or difficulty moving the knee
- Clicking, catching, locking or giving way sensations in the knee
Depending on the severity of your injury you may feel none, all or a combination of those symptoms.
Causes of meniscal tears
Meniscal injury can be caused by trauma (acute tears) or wear and tear (degenerative tears).
Acute meniscal tears are sudden traumatic injuries.
They usually happen with twisting or pivoting on a fixed foot, knocks to the knee, or when the knee is overstretched.
Sports like football and rugby increase your risk, while running is considered a low risk for acute tears.
How does wear and tear cause your meniscus to tear?
Research shows that meniscus tears in people over 30 years of age usually occur due to wear and tear. As you age, normal degenerative changes happen in your connective tissue, bones and muscles. They become a bit softer and less pliable over time and can’t take the same amount of force (load) as it used to.
The highest risk factors for degenerative meniscal tears are:
- increased age (> 60 years),
- male gender (up to 3 times more in men than women)
- work-related kneeling (>1 hour a day)
- repetitive squatting and stairs climbing (> 30 flights a day)
How do ligaments affect the menisci?
The medial meniscus is torn more often than the lateral meniscus because its attachment to the MCL holds it in place, making it less adaptable to forces, and more likely to get injured.
Meniscal tears from sports often happen together with other knee injuries, like ligament tears. This complicates rehab and can increase your recovery time.
For instance, waiting longer than 12 months to repair your ACL increases your risk of tearing your medial meniscus – leading to more knee problems later on.
How are meniscus tears diagnosed?
In most cases an experienced doctor or physiotherapist will be able to diagnose your injury by listening to how you injured it, what your symptoms are and assessing your knee’s movement through specific tests.
Do you need an MRI if you have a meniscal tear?
It’s not always necessary for you to have a scan to diagnose a meniscal tear. It’s only needed if a doctor feels that they cannot make an accurate diagnosis through performing the manual tests.
MRI helps doctors identify the location and type of tear and helps them decide on surgical options (if necessary). It can also help to rule out other injuries like ligament tears.
MRI alone is not reliable for diagnosing and directing treatment choices for meniscus tears. Up to half of people over 40 years of age have a meniscal tear with no symptoms, and it doesn’t bother them at all.
Is it worth having meniscus surgery?
In most meniscal tears, surgery isn’t the best option. Although surgery may have similar treatment outcomes to exercise-based rehabilitation programs, exercise is less invasive and less costly. Having surgery doesn’t take away the need for physical rehab – you will still need rehab to get back to your pre-injury activities after surgery.
The menisci are very important parts of the knee joints and they keep them healthy for longer. Removing a meniscus can cause osteoarthritis (OA) of the knee.
OA is the painful breakdown of cartilage and bone in the knee joints. It worsens over time and increases your risk of knee replacement surgery. Surgeons will rather save the meniscus, than remove it, in an effort to spare patients from OA.
Does surgery always improove symptoms?
If surgery is indicated, the location of your tear is an important deciding factor.
Can a meniscus tear heal?
A meniscus tear heals as long as there’s a good blood supply in the area. In the c-shaped ring of the meniscus, the blood supply zones are:
- The outer red zone (RZ): good blood supply, good chance of healing
- Middle zone (MZ): minimal blood supply, limited chance of healing
- The inner white zone (WZ): no blood supply, no chance of healing
Your meniscus tear doesn’t have to heal to regain full function
We know this sounds strange, but remember the study that we quoted earlier? That study showed that up to half of people over the age of 40 walk and run around with meniscus tears in their knees that don’t cause them any pain or swelling.
Can you regain full function despite the tear is still prsent?
What is the best treatment for a meniscus tear?
Progressive exercise-based rehabilitation programs are effective in healing most meniscal tears. A good rehab program will reduce pain in the knee joint, promote healing, improve knee and body function, and prevent future injury of the meniscus.
The Exakt health app contains a science backed program that guides you from acute meniscus injury back to running. It’s intuitive, so it uses the feedback you provide after each training session, to progress you through each of the 6 stages of the recovery plan.
Aims of first 3 stages:
- Settle the injury and control inflammation with modalities like PRICE
- Improve strength and control in your core, legs, and knees
- Get you gradually back to gentle pain-free activities
Aims of final 3 stages:
- Build your strength and endurance to higher levels
- Gradually get you back to running
- Prepare you for faster speeds and higher intensity workouts and runs
The ultimate aim of the program is getting you back to running stronger and fitter than before your injury, by gradually building up your strength and ability to take more load.
Conservative treatment vs. surgery
How long does it take to heal a meniscus tear?
Most straight-forward meniscus tears recover in about 4 -24 weeks with conservative treatment. The healing time depends on your unique injury history and symptoms, and the type of program you follow.
How can you prevent meniscal tears?
Running applies a force into your legs of up to 3-5 times your bodyweight. The menisci have the vital job of buffering that force, sharing it across the knee joints and out into the rest of the body.
To prevent meniscus tears, it’s important to keep excess forces to a minimum. Ways to do that include:
- Regular strength training keeps your knees strong and supported
- Balance exercises help you adapt better to awkward movements
- Losing weight decreases forces through joints
- A balance of high and low impact activities reduces overall impact
- Leaving enough rest between workouts promotes healing
- Supportive and well-fitting shoes keeps your body aligned from feet up
- Keeping joints flexible balances the body and improves movement
- A good warm-up and cool-down routine prepare and recover your body well
- Avoiding sudden increases in training allows your body to adapt to new loads
Now that you have a good overview of meniscus injuries, you may find it useful to get a deeper understanding of how the rehab process works and what type of exercises to do.