What Causes Weakness In Hand After A Rotator Cuff Surgery?

I had rotator cuff surgery in June (6 months post op now) with a nerve block. I thought it was great. Not a whole lot of pain. Now, I am having a hard time regaining strength in my arm. I have good range and rotation, but no strength. I have an aching in my upper forearm (sometimes a shooting pain), numbness in my ring and pinky fingers after sleeping - and that is if I can find a comfortable sleeping position do to the arm aching. I had nerve tests done yesterday. She said my right (surgery) side showed a 5 on the ulnar nerve compared to the left at a 15. I feel right now, that I have exchanged one pain (shoulder) for another - and this one is more aggravating. What can I expect? Will this heal? Another surgery? Help. I am not back to work yet.