Why do I have severe pain in my thighs? Laura?

I had two back surg. a couple of years ago. I have severe pain in my thighs. It feels as though they are being broken over and over. Can anyone help me pinpoint what is going on? After the last surg. I have experienced chronic moderate to severe pain in lower back and thighs. The pain in my thighs are so intensive that I shreek out in pain. Somebody please help me find out what this is. I would appreciate it emencly! Thank-you, Respectfully, lange00000@yahoo.com