Who Benefits From Meniscus

What are the menisci?
They are two C-shaped structures that lie between the femur and tibia on the inside (“medial”) and outside (“lateral”) aspects of the knee. They predominantly consist of water and collagen fibers. Historically, the function of the menisci was unclear, and some even considered them to be vestigial remnants of embryonic tissue like the appendix. For this reason, complete excision of the meniscus (“total meniscectomy”) was not infrequently performed in the setting a symptomatic meniscus tear. Unfortunately, total meniscectomy in young patients has been shown to dramatically accelerate degenerative wear in the knee. These include:

o Load Tranmission – the menisci are responsible for transmitting between 50% to 70% of the loads across the knee joint.

o Shock Absorption
o Joint Lubrication and Nutrition

It is also known as a torn cartilage that can affect severely the mobility of one’s knee joint. This injury is usually experienced by athletes who play contact sports such as boxing, football, and basketball to name a few.

What is the anatomy of the menisci?
There are two menisci, a medial one on the “inside” of the knee and a lateral one on the “outside” of the knee. The medial meniscus is C-shaped, while the lateral meniscus is more semicircular in shape. Both rest on the tibial surface and are anchored to the bone at the front and back of the plateau (“meniscus roots”).

There are three levels of meniscus tear, each with its own symptoms as follows:

Each meniscus can be divided into portions based on (i) location within the knee, or (ii) blood supply. By location, the meniscus can be divided into a (i) posterior horn, (ii) body, and (iii) anterior horn. These terms are helpful to describe the location of meniscus tears. Tears in the posterior horn are the most common.

The blood supply of the meniscus comes from the periphery where it attaches to the lining of the knee joint (“capsule”). This classification becomes important when evaluating meniscus tears and considering their capacity for healing after a surgical repair.

What are meniscus tears in athletes?
They have affected athletes of virtually every sport.

In athletes, a meniscus tear usually is a traumatic origin. They result or abnormally high forces that fail the substance of the meniscus. While these are often the result of forceful twisting or pivoting movements, they can also occur with seemingly innocuous activities such as squatting or jogging. From baseball catchers to professional defensive lineman, virtually every sport and position player has been affected by this injury. Some names you will recognize include Osi Umeniyora, Johan Santana, Sedrick Ellis, and Shawne Merriman – all have battled meniscus tears in their athletic career.

1. Minor Tear

• You experience a little pain and swelling of your knee joint. This usually lasts about two to three weeks.

In older patients, a meniscus tear may not be of traumatic origin but rather part of degenerative changes in the knee. These tears are often accompanied by some arthritic changes in the knee and are referred to as “degenerative” tears.

2. Moderate Tear

How is a meniscus tear classified?
A Meniscus tear can be classified in various ways – by anatomic location, by proximity to blood supply, etc. Various tear patterns and configurations have been described. These include:

o Radial tears
o Flap or Parrot-beak tears
o Peripheral, longitudinal tears
o Bucket-handle tears
o Horizontal cleavage tears
o Complex, degenerative tears

These tears can then further classified by their proximity to meniscus blood supply, namely whether they are located in the “red-red,” “red-white,” or “white-white” zones.

• Pain gradually increases and you experience it either at the side or center of the knee joint. Swelling heightens and limits the mobility of your knee. Although you can still walk, you’ll have the feeling of your knee becoming stiff.
• Sharp excruciating pain when twisting the knee or squatting.

The functional importance of these classifications, however, is to ultimately determine whether a meniscus is REPAIRABLE. The repairability of a meniscus is dependent upon a number of factors. These include:

o Age
o Activity Level
o Tear Pattern
o Chronicity of the tear
o Associated Injuries (Anterior Cruciate Ligament Injury)
o Healing Potential

3. Severe Tear

• As the torn cartilage moves to the joint area, your knees may be wobbly and it can, at anytime, give way.
• You can hear clicks on your knees and you’ll experience locked knee.
• You may experience severe limitations in the mobility of your knee and the ability to walk.

You can find additional essays at this site on Knee Injury Diagnosis.