A meniscus is a disk-shaped piece of cartilage that acts as a shock absorber inside a joint. Each knee has one lateral meniscus under the outer knob of the thighbone and one medial meniscus under the inner knob of the thighbone. Each meniscus acts as a natural cushion between the thighbone (femur) and shinbone (tibia). The two cushions prevent excess wear and tear inside the knee joint by keeping the ends of the two bones from rubbing together. Each meniscus also absorbs much of the shock of jumps and landings and helps to distribute joint fluid evenly to lubricate and nourish the knee.
In the United States, a torn meniscus is the most common reason for knee surgery.
The symptoms of a torn meniscus can include:
Your doctor will inspect both your knees to compare your injured knee with your uninjured one. He or she will check your injured knee for signs of swelling, tenderness and fluid inside the knee joint. If your knee is not locked, the doctor will bend your injured knee and check for clicks, snaps and "catches" within the joint. Your doctor also will evaluate your knee's range of motion and will maneuver your knee to see whether your meniscus is sensitive to pressure. For example, in the "McMurray test," the doctor bends the leg at the knee, and then rotates it inward or outward while straightening it. If you feel pain during this test or if there is a "click" sound as your leg rotates, there is a good chance that your meniscus is torn.
If the results of your exam suggest you have a torn meniscus, you may need more tests, including:
If you have arthroscopic surgery to treat your torn meniscus and your job involves sedentary work (mostly sitting), you may be able to return to work one to two weeks after surgery, with full recovery in about four to eight weeks. If you are an athlete or your job requires a lot of physical activity, it may take three to four months after surgery before you feel like you have as much function in your knee as you require.
Although it's hard to prevent accidental knee injuries, you may be able to reduce your risks by:
There are several options for treating a torn meniscus:
If you need surgery to correct a torn meniscus, it usually can be done using arthroscopy (camera-guided surgery) as a same-day procedure. After the procedure, you will begin physical therapy to help strengthen your knee muscles, reduce pain and swelling, and return the knee's full range of motion.
Call your doctor to schedule an evaluation whenever an injured knee:
In most cases, the outlook is very good. If your torn meniscus has been repaired surgically or partially removed, you probably will be able to resume your normal athletic activities once you've finished physical therapy.
According to long-term studies, most people who have had a meniscus repaired feel very satisfied with the results of their surgery, even 10 or 11 years after the procedure. However, some people with meniscus injuries eventually develop arthritis in the injured knee. Typically, arthritis develops many years after the injury. The highest risk is among those who've had a part or all of the meniscus removed, because significant injuries requiring this surgery often damage the joint but also because these surgeries take away some or all of the cushioning effect of the meniscus.
National Institute of Arthritis and Musculoskeletal and Skin Diseases
1 AMS Circle
Bethesda, MD 20892-3675
National Rehabilitation Information Center (NARIC)
4200 Forbes Blvd.
Lanham, MD 20706
American Orthopedic Society for Sports Medicine
6300 North River Rd.
Rosemont, IL 60018
National Athletic Trainers' Association
2952 Stemmons Freeway
Dallas, TX 75247-6196
Phone: (214) 637-6282
Fax: (214) 637-2206
American Physical Therapy Association
1111 North Fairfax St.
Alexandria, VA 22314-1488
Phone: (703) 684-2782
Toll-Free: (800) 999-2782
Fax: (703) 684-7343