Meniscal tears are among the most common knee injuries. Athletes, particularly those who play contact sports, are at risk for meniscal tears. However, anyone at any age can tear a meniscus. When people talk about torn cartilage in the knee, they are usually referring to a torn meniscus.
Two wedge-shaped pieces of cartilage act as "shock absorbers" between your thighbone and shinbone. These are called meniscus. They are tough and rubbery to help cushion the joint and keep it stable.
Symptoms of an Injured Meniscus
In sports, a meniscus tear usually happens suddenly. Severe pain and swelling may occur up to 24 hours afterward. Walking can become difficult. Additional pain may be felt when flexing or twisting the knee. A loose piece of cartilage can get stuck in the joint, causing the knee to temporarily lock, preventing full extension of the leg.
If you have a torn meniscus, you may:
A meniscus tear can occur when the knee is suddenly twisted while the foot is planted on the ground. A tear can also develop slowly as the meniscus loses resiliency. In this case, a portion may break off, leaving frayed edges.
Diagnosis of a Meniscus tear
A magnetic resonance imaging (MRI) scan is often used to diagnose meniscal injuries. The meniscus shows up as black on the MRI. Any tears appear as white lines. An MRI is 70 to 90% accurate in identifying whether the meniscus has been torn and how badly. However, meniscus tears do not always appear on MRIs.
Meniscus tears, indicated by MRI, are classified in three grades. Grades 1 and 2 are not considered serious. They may not even be apparent with an arthroscopic examination. Grade 3 is a true meniscus tear and an arthroscope is close to 100% accurate in diagnosing this tear.
Treatment of the tear will depend on the type of tear you have, its size, and location.
The outside one-third of the meniscus has a rich blood supply. A tear in this "red" zone may heal on its own, or can often be repaired with surgery. A longitudinal tear is an example of this kind of tear.
In contrast, the inner two-thirds of the meniscus lacks a blood supply. Without nutrients from blood, tears in this "white" zone cannot heal.
Along with the type of tear you have, your age, activity level, and any related injuries will factor into your treatment plan.
Meniscus surgery is a quick straight forward procedure that usually taken a few minutes. It can be done as a day care surgery i.e. you do not need to stay in the hospital overnight, but some patients may stay in the hospital for 24 hours due to insurance compliance. Patients are able to walk independently with/without a crutch within a few hours after meniscus trimming. Most of the patients are fully recovered in 2-3 weeks and resume all normal activities.
If you have had a meniscus repair procedure, you will need to use crutches for about a month to keep weight off of your knee.