The meniscus is a type of cartilage cushion in the knee that protects the true joint cartilage from injury as the thigh bone moves over the top of the leg bone. There are actually two menisci in your knee, one is on the inner (medial) side of your knee and the other is on the outer (lateral) side of your knee. The meniscus is C-shaped and has a wedged profile that allows it to conform to the shape of the thigh bone. The most common mechanism of a meniscus tear is when the knee joint is bent and then twisted. The meniscus can often be injured at the same time as one of the major ligaments in the knee.
Symptoms of a meniscus tear include:
- Pain along the joint line of the knee.
- Swelling that starts a few hours after the injury.
- Mechanical symptoms include joint locking or the inability to completely straighten the knee.
- Popping or clicking within the knee.
A physical exam of the knee will often diagnosis a meniscus tear. An X-ray should be done to make sure that there is no bone fracture. An MRI should then be done to confirm the physical exam findings and make sure that there are no associated injuries.
Treatment of a meniscus tear, in a young person, requires surgery. If the tear can be repaired, then it should be fixed. If the tear is not fixable, then the torn portion may be removed back to stable edges to prevent propagation of the tear and any further injury to the overlying cartilage. If a repair is performed, then physical therapy will be necessary for three months before returning to sports.