What is a Meniscus?

It's a soft pad of cartilage in your knee between the thigh and leg bones. It acts as a shock absorber. There are two menisci in each knee - medial meniscus (the inner one) and lateral meniscus (the outer one).

Normal functions of meniscus :

• It acts as a cushion between 2 hard surfaces.
• It stabilizes the joint.
• It reduces friction & protects the surrounding bone from wear and tear.
• It increases the surface area of contact between the 2 bones & allows even weight transfer across the joint.

What causes meniscus to tear?

Traumatic:

• Forced twisting/rotation of knee
• A sudden pivot or turn
• Deep squatting
• Heavy lifting
• Sports that require sudden turns & stops

Degenerative :

The meniscus weakens with age. Due to ongoing arthritis/obesity, such poor quality meniscus tissue is likely to get torn on seemingly normal activities of daily living.

What are the symptoms of Meniscus tear?

• Pain.
• Stiffness and swelling.
• Catching or locking of your knee.
• Inability to move your knee through its full range of motion.
• Clicks felt while moving the knee.

How are meniscus tears diagnosed?

Your doctor will recommend for a MRI scan to see meniscus injuries.

What are the types of meniscal tear?

Intra-substance/Incomplete Tear: These tears may be a common finding in many MRI reports, usually asymptomatic. Many often, they may present as early signs of age related degeneration in the knee. Most do not require surgery.

Longitudinal tear: It is another common pattern which extends across the length of the meniscus and requires surgical repair if deemed long enough/unstable. Small tears may require simple trimming.

Radial Tear: They are the most common type of meniscus tear. They are called so because of their shape/pattern and usually extend across the inner white zone of the meniscus. Hence they are difficult to heal and often require some surgical treatment.

Horizontal Tear: As the name suggest it cuts across the expanse of the meniscus horizontally. Tears may be stitched together if they are in Zone 1 or 2.

Flap Tear: This is an unusual pattern ,where the flap causes catching / locking sensation in the knee. The interfering flap tissue may be removed without removing much of the meniscus.

Complex Tear: A complex tear has a combination of tear patterns. It often involves radial, oblique and horizontal tear patterns. In young patients, all efforts are made to repair even the complex tears, although with increasing patient age they are usually trimmed off.

Bucket-Handle Tear: It is a large, full thickness vertical tear which causes a strip of meniscal tissue to get displaced within the joint and hinder free movement of the knee. It causes locking of the knee. It most often requires surgical repair.

What is the treatment of meniscus tear?

The treatment will depend on a number of factors like grade of tear, age, symptoms and activity level.

More importantly, stress will be given to the type, size, and location of the injury.

The outer third of the meniscus has a good blood supply. A tear in this "red-red" or the next “red-white”zone may heal on its own (if its small, stable), or may require surgery in the form of repair (large tear, symptomatic locking).But the overall healing chances are reasonably good.

In contrast, the inner two-thirds of the meniscus has a poor blood supply. The lack of healing nutrients from this limited blood supply results in poor healing of tears in this “white” zone. Since the pieces cannot grow back together, symptomatic tears from this zone that have failed to heal by non-surgical management are usually trimmed surgically (meniscectomy) – i.e. Removal of just the piece of meniscus which has not healed.

Special mention - Root tear of the meniscus :

It is usually a degenerative type of tear pattern seen in middle aged individuals. In this type, the meniscus gets uprooted from its attachment from the leg bone(tibia), most commonly in the back of the knee.

It is severely discomforting to the patients causing :

• Painful weight-bearing
• Restricted and painful knee bending
• Inability to squat/sit cross-legged

Treatment :

A meniscal root tear is akin to having no meniscus at all. It can not heal on its own. Hence, most often, it requires surgical treatment in the form of debridement or repair. Repair option is best suited for relatively young individuals with minimal pre-existing arthritis.