MRI (magnetic resonance imaging) is a very good tool for identifying many problems. However, in the case of small tendon tears in the shoulder, MRIs can be wrong. In fact, studies show that more than half of rotator cuff tears in the shoulder come out negative on MRI when in fact there is a problem. This is called a "false negative."

MRIs are still widely used because they do not require surgery or injecting anything into the body. In other words, the test is noninvasive. But if the MRI is normal, there may still be a problem that needs to be identified.

The next step is often arthroscopic surgery. In this procedure, the doctor inserts a small camera into the joint. This allows the doctor to see inside the joint and carefully examine all of the surrounding structures. Even the tiniest tears of tendon, ligament, or cartilage can be seen with this device. Repairs are usually made at the same time.