What is a Meniscus tear?

By Sydney CBD Osteopath Dr Marcus Ng

Diagram of the knee joint - mensicus, femur, tibia, fibular and some ligaments and tendons

So you have a meniscus tear, now what? In this blog, we will address some of the questions you may have regarding, what is a meniscus tear? What causes a meniscus tear? The signs and symptoms of a meniscus injury? The treatment and prognosis of meniscus tear.

While being diagnosed with a meniscus tear is never ideal, it is important to know that you are not your MRI! Two thirds of people over the age of 50 who demonstrate a meniscus tear are asymptotic (i.e. they do not report any issues physically despite such findings on their MRI report)¹.

Even if you have symptoms of a meniscus tear, surgery is not the only solution to improve your quality of life. Physical therapy has been found to be just as effective as surgery; it also has minimal recovery time and less financial burden².

What is the meniscus?

The Meniscus are cartilage which act as shock absorbers for the knee joint - injury can lead to clicking, popping, locking and pain

The menisci are two wedge-shaped pieces of cartilage that sit between your femur (thigh bone) and tibia (shin bone). The purpose of the meniscus is to act as a shock absorber at the knee and also allow the bones to glide smoothly over each other.

The menisci are two pads of crescent shaped fibrocartilages that have blood supply from the perimeter edge flowing into the center. The center is avascular (i.e. lack of blood vessels). It is because of this that by adult age, any injury to the central parts of the meniscus have a very poor healing rate compared to the outer edge. Thus the site of injury will also determine the prognosis (recovery time), type of surgery and/or rehabilitation.

What causes a meniscus tear?

Blood supply to the meniscus cartilage is poor - this leads to longer healing times from meniscus injury

The most common cause is an injury from a traumatic incident, typically when the foot is fixed to the ground and a forceful twisting motion of the knee occurs. Thereafter, the pain progressively worsen over time and there may be a sensation of or audible click or pop as the knee is moved through its range of motion.

For the older population, high prevalence of meniscus damage can be found in people with osteoarthritis. Moreover, as they age, the degeneration of the knee complex means they are more susceptible to meniscal tears even from simple everyday movements. Thus, prevention is the best way to minimize the chance of injury as you age.

Signs and Symptoms of meniscus tear:

You may experience one or multiple sign and symptoms listed below. Knowing how the injury occurred will paint a clearer picture if there is any meniscus involvement.

Pain, especially when twisting or rotating the knee.
Swelling or stiffness.
Joint line tenderness.
A popping sensation at the time of and after injury.
Locking sensation after the injury.
Unable to move the knee through its full range of motion, especially having difficulty in straightening the knee into full extension. This could also present with a “clicking” sensation. End range knee flexion can also painful.

If any of these signs and symptoms persists; please consult your osteopath and physiotherapist.

What you can do right now for a meniscus tear?

In the first three days following an injury, apply RICE (Rest, Ice, Compress and Elevation). Also seek advice from your pharmacist regarding the use of anti-inflammatory medication (e.g. Aspirin and Ibuprofen). This will aid in reducing pain and swelling in the knee. If you are still concerned about your symptoms consider further investigation from your osteopath or physiotherapist for a full physical examination.

After a thorough history taking to understand the mode of injury, your osteopath or physiotherapist will perform some orthopedic tests. These are designed to stress the meniscus to see if the symptoms can be reproduced.

To further confirm the diagnosis, a referral for MRI can be made. MRI is currently the benchmark for non-invasive diagnosis of meniscus injuries. An X-Ray typically isn’t recommended because it will not show the meniscus; it can only can show signs affecting the bones such as osteoarthritis.

In Australia, as of November 2018, Medicare rebate for MRI will only be covered if a patient is suspected of a meniscus tear between the age of 16-49 years old³. Unfortunately, for those who are 50 years or older MRI would not be covered under the current rebate scheme, which is a shame because meniscal tears are highly prevalent in this population.

Osteopath and Physiotherapy treatment for meniscus tear?

Recent studies have shown physical rehabilitation is just as effective as surgery for a meniscus tear.

“We performed a large multicentre randomised trial in nine Dutch hospitals, and we included 320 patients between 45 and 70 years old, and all of them obviously had a meniscal tear. And half of them received surgery which removed the torn part of the meniscus, and the other half received a standardised physical therapy program. And what we did is we followed them up for two years and we found that after the two years, that both groups improved equally in knee function.“²

The purpose of rehabilitation is to help regain the strength and flexibility to the structures around the knee and this also prevents possible future injuries. These exercises are aim at the quadriceps, hamstrings, calf and hip⁴. Some of which include.

End Range Knee Extension – place a rowed-up towel underneath the knee, push you knee straight down into the towel
Straight Leg Raise – keeping the knee straight, bring your leg up toward the ceiling at the hip.
Hip Extension – keeping the knee straight, bring your leg up toward the ceiling at the hip.
Hamstring curl – bending at the knee, bring your heel towards your bottom.
Bridge on Heels – pushing off your heels, lift you bottom off the table
Calf Raise – pushing off the ball of your feet, raise you heels off the ground
Shallow Knee Bend – feet shoulder-width apart, bend at the knee up to 30°

https://youtu.be/VGXTrTOZPnQ

Getting surgery will depend on type of tear, size of tear, which part of the meniscus is torn and how much damage is present. The current model aim to preserve as much of the meniscus as possible. Aiming to not remove but to protect, repair or reconstruct, in order to prevent early development of osteoarthritis by restoring the natural structure, function, and biomechanics of the meniscus⁵.

How long until meniscus tear gets better?

There are many factors that determine the recovery rate of a torn meniscus. In general recovery rate ranges from 1-3months.

These include:

Where is the tear located?
How extensive is the damage?
What symptoms are you experiencing?
What activities do you plan to do in future?
The type of intervention you choose for rehabilitation
How compliant you are with the rehabilitation

Since we have established the signs and symptoms may or may not correlate with the findings on an MRI. We recommend keeping the legs strong via regular exercise during and after rehabilitation. The strengthening and stability of muscles and ligaments in the lower limb will prevent possible injury or deterioration of the knees, and this includes the meniscus.