I have a large tear in my rotator cuff. So far I seem to be able to move my shoulder okay. Surgery has been recommended. Do I really need it?
Some rotator cuff tears can be treated conservatively with rehab. But these are usually not in athletes who are using the arm repetitively and with increased loads.

If you are not an overhead-throwing athlete, then surgery may not be needed. It is possible to strengthen the other muscles of the shoulder. The goal is to keep the overall balance in all motions. If the pull of the muscles is stronger in one direction or at a certain angle, then motion may be limited and/or painful. Keeping the overall balance in motion assures there will be normal, pain free movement.

Normal shoulder function depends on an intact rotator cuff, rotator cuff muscle force, and the force or strength of the deltoid muscle. When the deltoid contracts, the arm moves away from the body in a motion called abduction.

If there's a tear in the rotator cuff, an imbalance occurs. If the deltoid contracts without the counterbalancing contraction of the rotator cuff, the upper arm glides upward into the shoulder socket. This is called superior translation. The result of this abnormal motion can be a painful impingement syndrome.

Studies show that the uneven forces around the shoulder after a rotator cuff tear can actually lead to further damage to the rotator cuff. Early surgery to repair the tear can keep this from happening. The decision whether or not to do surgery depends on your age, level of activity, and type and size of tear.