Suggest Treatment For Severe Pain In The Left Shoulder Post A Rotator Cuff Surgery

Doc, I was in an accident approximately 3 months ago. There was an MRI/CT of my left shoulder showing a slight muscle tear, and a partial tear of my rotator cuff. I was in intense pain for the first week. Now, although the pain is less, I cannot achieve total manipulation of my left arm without severe pain in the L. shoulder radiating down the left arm. I m 59 years of age with no major heath problems, and was just wondering if I may need shoulder surgery to repair this e=injury. Also it has a major affect on my ability to sleep. Thanks