Pain in hip and thigh/ from back fusion or neurological

Approx. 6 yrs. ago, I had spinal fusion, L4 & 5, with rods and screws.  The surgery was a success and no more pain across my lower back.  Now, I am having trouble walking without pain in my right hip and down the right leg. I had been told I needed a hip replacement for hip dysplasia (I walk with my right foot pointed outward); but hip specialist says I do not need replacement, he thinks problem is from the back surgery or neurological.  When born, I was breech, my heart stopped for a while, and I have always walked this way.  My symptoms:  I walk less than one block, then right hip and thigh begins to hurt and I have to be very careful or I trip and fall.  This tires me out quickly.  Could this be from the back fusion or should I see a neurologist?