When a tear forms in the meniscal cartilage from degeneration or an acute injury. Fluid from the knee joint then leaks out of the tear forming a meniscal cyst. So, it is not a true cyst but an outpouching of displaced knee fluid. Also, the cartilage tear can form a one-way valve preventing the fluid from going back into the knee. The fluid then collects as a cyst below the knee cap.
Often, meniscal cysts form in people with a past history of a knee injury, cartilage damage, or contact or twisting sports. Also, the presence of arthritis predisposes to the formation of a cyst on the side of the knee.
What are the symptoms of a Meniscal Cyst?
The common symptoms of a meniscal cyst include the following.
- Tenderness along the joint.
- Firm bump at the site of the cyst, more commonly over the outside.
- Occasionally, a painless bump.
- pain behind knee.
- Associated non-specific findings may include knee swelling, joint line tenderness over the affected meniscus, “locking” of the joint or ligament injury.
What Causes a Meniscal Cyst?
They are usually associated with a type of meniscal tear called a horizontal cleavage tear. However, This kind of tear may be caused by over-rotation of the knee. It can also be caused by a direct impact to the front or side of the knee. Disproportionate force on the knees, such as when you run on an uneven surface, can also cause this type of injury.
When the meniscus is torn, a small cyst can form adjacent to the tear. This cyst is thought to develop as part of the body’s healing response. Alone, a cyst is of little consequence and is present only secondary to the meniscus tear. However, the cyst itself can cause discomfort and may be noticeable over the joint line where the meniscus is torn.
However, Cysts may also be caused by degeneration of the meniscus. This is usually related to age or osteoarthritis.
What are the risk factors for a Meniscal cyst?
A Meniscal cyst caused by trauma is more common in active people under 40 years of age. Sports that require pivoting raise the risk. Examples are basketball, soccer, and football.
Other Risk factors for meniscal cysts include:
- Knee injury.
- Participation in contact sports like football, soccer, rugby, or tennis.
- Increasing age
- Ligament injuries, such as a torn anterior cruciate ligament.
How Can We Treat It?
As meniscal cysts arise from a degenerative torn meniscus, treatment reflects meniscal tear treatment. However, Common treatments include the following:
Anti-inflammatory medications, taken by mouth or injected directly into the knee, can be useful to reduce the pain and swelling symptoms associated with meniscal tears.
A short course of treatment provided by a physical therapist can help determine whether your knee will recover without surgery. Your physical therapist can help control pain and swelling in the knee area and work with you to restore full strength and mobility to your knee.
How can Surgery help in treating a Meniscal cyst?
Also, Your doctor may recommend surgery because:
- You still have pain after trying other treatments, such as rest and physical therapy.
- Your knee “locks up” instead of working normally.
- You may be able to reduce the risk of future joint problems
Arthroscopy to remove the meniscal tear is the procedure of choice. Often just removing the meniscal tear allows the cyst to decompress (shrink) and disappear without other treatment. Removing the cyst is not necessary. Simply removing the torn meniscus by arthroscopy is enough to stop it from coming back.
Also, Surgery may help you reduce the risk of other joint problems, such as osteoarthritis. There are no long-term studies to prove it, but many doctors believe that successful meniscus repair helps to evenly spread the stress placed on the knee joint.
Is a meniscal cyst dangerous?
A meniscal cyst is not dangerous. In some patients, a meniscal cyst will become very large. In those cases, the way to treat the cyst is to repair the meniscus tear.
How to Prevent a Meniscal cyst?
Exercise or other interventions such as bracing can prevent us from the meniscal cyst. Practices that can help keep your knees strong include:
- Regular exercise- to help strengthen the muscles that support your knees.
- Staying physically active-to prepare your body for the demands of a sport or strenuous activity.
- Avoid twisting or turning quickly while on the ground, to help prevent stress to the knee that can cause a meniscal tear.
However, If you already have knee problems, your physical therapist can help you develop a fitness program that takes your knees into account. Some exercises are better than others for those with a history of knee pain.