An Orthopedic Problem - Left Shoulder. I Went To A

An orthopedic problem - left shoulder. I went to a specialist today and he misdiagnosed my problem. Gave me an injection in the back part of my left arm. Then I told him the pain was on the top of my shoulder and said that was my rotator cuff. The injection really hurt. But some of the pain subsided. Still have pain down my upper arm when I try to pivot it out. Can't lift my arm above my head, can't take a shirt off. Besides the rotator cuff what else could be the problem. Have no heart or GI problems.