What can cause leg pain in both legs, sometimes it like a fever like pain , i had back surgery in 1999 two steel rods and five screws when they hurt low?

a few common causes: You could have nerve irritation from scar tissue, a new disc herniation or narrowing around 1 or more nerves. There are also other possible causes like the sacroiliac joints or irritated muscles. In my office you would get x-rays and MRI to get a better look at the spine and nerves. Therapy or injections could help.

Many possibilities: They could be several possible anwsers, they all deserve proper investigation.You could have a recurrent disc herniation, epidural fibrosis or arachnoiditis or even peripheral neuropathy.You should see the surgeon who performed your surgery for a proper diagnostic workup.