Who can I sue for my work accident almost three years ago?

I have a tendon tear at 70% then I got another MRI with tint last January and it says the same plus more damage on my left shoulder, I got the surgery like a month and half ago, and the doctor who did the surgery put on her report that I didn't have a tendon tear, at all, but she did found something different and she "fixed" with surgery, now I lost movement range and I have big scars on my shoulder where she says she didn't found a tendon tear, can I sue them.? And if I can who will be the person I'm going to sue? Please help.