I tore the rotator cuff in my left shoulder years ago. Now I'm having problems with my right shoulder. It doesn't seem quite like the rotator cuff problem I had before. This seems stiffer and less painful. How can I tell the difference between old age and a rotator cuff tear?

Finding out what's wrong with a patient's shoulder can be a difficult task even for the best orthopedic surgeon. The shoulder joint is actually a group of four different joints with many layers of soft tissue.

Besides rotator cuff tears, arthritis, impingement, bone spurs, and tumors can cause a stiff shoulder. Your history (how and when the symptoms came on) can help the physician sort out one problem from another. For example with a rotator cuff problem the pain occurs with motions as the arm is raised or lowered. With capsular stiffness pain doesn't occur until the patient reaches the limit of joint motion called the end range.

There are various clinical tests a doctor can perform to help sort out the cause of a shoulder problem. Imaging studies such as X-rays, CT scans, and MRIs may be needed.

Sometimes the only way to know for sure is to perform an arthroscopic exam. The doctor inserts a long, thin needle into the joint. A tiny TV camera on the end of the tool allows the surgeon to view on a TV screen what's going on inside the joint. A less invasive test is the use of lidocaine (a local anesthetic) injected into the joint. Pain relief occurs when there's a rotator cuff problem but not with a stiff shoulder.