Your knee is composed of three bones: the thighbone (femur), the shinbone (tibia), and the kneecap (patella), as well as the soft tissue that connects them. Between your femur and your tibia are two C-shaped discs of cartilage that act as shock absorbers for the bones and help keep your knee stable. These are your menisci (plural of meniscus), and they can be torn, particularly if the knee twists suddenly while it is bent.
Viewed from the front or back, the meniscus is wedge shaped. This shape helps keep the rounded surface of your femur from sliding off the flat top of your tibia. The outer edges of this wedge receive a good supply of blood, and tears in this part of the meniscus heal well on their own. The inner part of the meniscus, however, has no direct blood supply. Tears in this area can require surgery to correct.
A torn meniscus is a common sports injury, particularly in contact sports like football and hockey. Meniscus tears can range from minor to severe, depending on the extent of the damage, and they can make it difficult for the knee to function properly.
What Are the Symptoms of a Meniscus Tear?
The symptoms of a torn meniscus will vary depending on the severity of the tear. Someone who gets a minor tear may only have slight pain and swelling that goes away after 2 or 3 weeks.
Moderate to severe tears also might cause these symptoms:
- a "pop" in the knee when the tear occurs
- pain in the center or side of the knee, especially when twisting the knee or squatting. This will usually go away after a couple of weeks but can come and go for much longer if the tear is not treated.
- swelling and stiffness in the knee that gets worse over the first 2 or 3 days after the injury occurs
- limited range of motion
- the knee feeling as if it is locking or popping when bending; it might not straighten
- the knee feeling like it is giving way without warning
