I had a spinal fusion at L5 to S1 20 yrs. ago with bolts and steffe plating. Since them I have had PT, injections, used NSAID's and found some relief but pain into my right leg is getting worse and the tingling and numbness comes and goes. Now I have a knocking in my low back when I walk which radiates up my spine. I can hear clumk, clumk, clumk when I move and it burns when I sit. Is this an SI problem. I have had numerous MRI's and Milograms but the hardware from my fusion distorts the pictues so makes it hard to see what is happening. The doctor thinks stenosis and the disc above the fusion is gone.