Severe pain in right thigh. Cannot bear weight on right leg. Pain occurs if I sit in wrong position with any weight on back of thigh. Lost balance in night when I got up. Previous right hip replacement Nov 4 2014. Previous back and knee pain due to MVA last spring (2014)which hasn't abated. Feels as if there is a problem with metal rod in leg not with back radiating pain. What would be symptoms if problem is with metal rod as opposed to pain radiating from back?