Diagnosis

A torn meniscus often can be identified during a physical exam. Your doctor might move your knee and leg into different positions, watch you walk and ask you to squat to help pinpoint the cause of your signs and symptoms.

Imaging tests

• X-rays. Because a torn meniscus is made of cartilage, it won't show up on X-rays. But X-rays can help rule out other problems with the knee that cause similar symptoms.
• MRI. This uses radio waves and a strong magnetic field to produce detailed images of both hard and soft tissues within your knee. It's the best imaging study to detect a torn meniscus.

Arthroscopy

In some cases, your doctor might use an instrument known as an arthroscope to examine the inside of your knee. The arthroscope is inserted through a tiny incision near your knee.

The device contains a light and a small camera, which transmits an enlarged image of the inside of your knee onto a monitor. If necessary, surgical instruments can be inserted through the arthroscope or through additional small incisions in your knee to trim or repair the tear.