I had PMR 3 years ago. treated with prednisone and resolved it. In the last six months I have felt that sharp pain at about my middle thigh down through my knee even into my calf. Particularly on the right side and some on the left. I finally went to see an orthopedic Dr. Mainly because I tried some leftover prednisone for 5 days and no change. He ordered an MRI of the thigh, xrays of the knee and both hips. I have severe Osteoarthritis with bone spurs of the right hip and moderate of the left. I am scheduled for hip replacement. I am almost 74. Steroids can mask many things. Not sure any of this fits you but as they say a pain in the ass may not be coming from the ass. Hopefully you can figure it out. good luck.