The meniscus is a commonly injured structure in the knee and can occur in any age group.
There are two menisci between the shinbone (tibia) and thighbone (femur) in the knee joint. The C-shaped medial meniscus is on the inside part of the knee, closest to your other knee. The U-shaped lateral meniscus is on the outer half of the knee joint. These two menisci act like shock absorbers in the knee. Forming a gasket between the shinbone and the thighbone, they help spread out forces transmitted across the joint. Did you know that walking puts up to two times your body weight on the joint and running puts about eight times your body weight on the knee? As the knee bends, the back part of the menisci takes most of the pressure. The menisci adds stability to the knee joint. They convert the surface of the shinbone into a shallow socket, which is more stable than its otherwise flat surface. Without the menisci, the round femur would slide on top of the flat surface of the tibia.
Meniscal injuries can occur at any age, but the causes are somewhat different for each age group.
In younger people, the meniscus is a fairly tough and rubbery structure. Tears in the meniscus in patients under 30 years old usually occur as a result of a fairly forceful twisting injury. In the younger age group, meniscal tears are more likely to be caused by a sport activity. The tissue that forms the menisci weakens with age, making the menisci prone to degeneration and tearing.
People of older ages often end up with a tear as result of a minor injury, such as from the up-and-down motion of squatting. Most often, there isn't one specific injury to the knee that leads to the degenerative type of meniscal tear. These tears of the menisci are commonly seen as a part of the overall condition of osteoarthritis of the knee in aging adults. Degenerative tears cause the menisci to fray and become torn in many directions.
The most common problem caused by a torn meniscus is pain. The pain is usually felt along the side of the knee, but may also be felt around the whole knee. The knee may swell, which will cause it to feel stiff and tight, but this is not unique to meniscal tears. If the tear is large, you may experience “locking” of the knee. This is when you try to move your knee, but are unable. This may happen with a large meniscal tear if part of the tear gets caught in the mechanism of the knee.
Depending on the extent of the injury, your doctor may suggest surgical intervention. Your course of treatment will most likely involve physical therapy, either before or after surgery, or possibly both. The goal of physical therapy initially will be to reduce inflammation, if present along with restoring range of motion. Your therapist will utilize various hands on techniques as well as exercise prescription to regain range of motion as well as to increase the strength around the knee, thigh and hip. Your treatments may also involve modalities such as electrical stimulation and ice. Additionally, your therapist will give you advice regarding activities to do and not to do, and will prescribe a home exercise program to continue once you are discharged from physical therapy.