Diagnosis Physical exam An exam by a qualified doctor can often lead to the diagnosis.  Tenderness directly over the meniscus is often a sign of the tear.  X-rays are used to make sure there is not a broken bone.   MRI MRI is used to prove the presence of a meniscus tear.  During an MRI, the patient lays on a table with his or her knee inside a large magnet that takes some sophisticated pictures of the inside of the knee.