Your knee is a hinge joint formed by your thigh bone and your shin bone. These two bones come together and are stabilized by cartilage to help hold your knee in place. Between the two bones are two pads of cartilage that are known as the lateral and medial meniscus. They act as shock absorbers to help prevent the two bones from rubbing together and help your knee move smoothly. Over time this cartilage can begin to degenerate, causing pain and the inability to move your knee freely.
As you age and your cartilage becomes worn from supporting your weight, it can begin to weaken and become thinner. Conditions such as arthritis and other joint diseases can result in your meniscus wearing away, resulting in a weakening of the overall structure of your knee. This often causes a tear that can require treatment or surgery to repair. The most common cause of a sports-related meniscus tear is being hit on the outside of your knee, but you can damage a degenerated meniscus while performing everyday tasks, since the cartilage is weakened.
What Is Going On In My Knee?
A degenerative meniscus occurs as part of the normal aging process due to the breakdown of the collagen fibers that make up the cushion between your thigh and shin bone. This breakdown weakens the support provided to your knee, making it easy to tear your meniscus. Tears that result from a degeneration of the meniscus rather than trauma usually occur horizontally -- that is, they tear through the meniscus, producing a top and bottom portion. This horizontal tear can result in your knee "catching," or "locking," according to an article edited by Carol C. Teitz, M.D., on The University of Washington Department of Orthopaedics and Sports Medicine website.
Symptoms of Degenerative Meniscus
You can have a degenerative meniscus and not even know it until your cartilage finally tears. The degeneration can be the result of years of high-impact activity or normal wear and tear over time, but often this weakening causes your cartilage to rip apart. This tearing can result in pain, your knee being difficult to move, a feeling of weakness in your knee and/or an inability to move your knee as freely as before. Problems with your knee that cause any of these symptoms should immediately be examined by a doctor.
Treatment for A Degenerative Torn Meniscus
A torn meniscus can require surgery whether it is the result of a degenerative condition or a traumatic injury. Whether you require surgery depends on your age, activity level, and the type and level of tear that you've sustained. If your condition doesn't require surgery, it's most often treated with anti-inflammatory drugs coupled with rest, ice, compression and elevation, known as RICE. If your cartilage has degenerated to the point that these treatments are ineffective, you may be required to undergo a knee arthroscopy, where a surgeon will either repair or replace the cartilage.