The knee is a hinge-type joint. The thigh bone (femur) attaches to the shin bone (tibia) with the oval kneecap in the front. The joint may be thought of has having three compartments; the inner, outer and front compartments. There also normally is a thin, smooth covering of cartilage over the bones in the joint that allows normal, smooth and painless motion. There are two larger cartilages in the knee, which help to stabilize and cushion the knee joint; each is called a meniscus the one on the inside compartment is the medial meniscus, and the one on the outside compartment is the lateral meniscus.
Abnormal use or abnormal twisting pressure on the joint may tear a meniscus. If there is osteoarthritis in the knee, a meniscus becomes thinner than normal, and is torn more easily. Because muscles and ligaments support and protect the knee, injuries or weakness in these may increase the chance of a meniscal tear.
The knee may click, lock or feel unstable if there is a tear in a meniscus. The knee may swell up at first after an injury. Usually the pain is worse with twisting motions or squatting down. The pain may be sharp, and sometimes the knee aches after resting.
Along with a history about knee symptoms, an examination often suggests a torn meniscus is the diagnosis when pain is felt as the knee is moved and rotated. The normal knee range of motion may be painful, or sometimes limited. X-rays are helpful in showing osteoarthritis, but will not show a tear in a meniscus.
The treatment of a torn meniscus depends upon the severity of the pain and knee stability. Efforts to rebuild joint cartilage are still in the early research stages. Initial treatment to reduce pain often consists of weight loss (if necessary) and exercises to strengthen the knee muscles. Water exercise classes may be especially helpful. For more severe pain, medications may be recommended. These may include over the counter medications such as Tylenol (generic = acetaminophen) Aleve (generic = naproxen), Motrin (generic = ibuprofen) or aspirin. Various prescription medications which belong to a group of medications called ‘non-steroidal anti-inflammatory medications (or ‘NSAIDs’ for short) are commonly recommended. Some of the more commonly prescribed of these include medications such as Celebrex, Motrin, Naprosyn, Mobic, Voltaren, Relafen and Lodine. (a complete list is available at the reference below).
More severe pain may be treated with injections of a cortisone-like medication into the joint, but this will not repair the damaged meniscus. Small tears may be treated with physical therapy. Sometimes braces are helpful in providing stability and protecting the knee. If these measures fail, or if the meniscus is severely torn or out of place in the knee joint, arthroscopic surgery may be recommended. This is normally done using a device called an arthroscope (a flexible surgical instrument with a fiberoptic camera) that is inserted through small incisions into the knee joint by an orthopedic surgeon and the damaged meniscus is repaired or removed.