I Had A Spinal Mastectomy Six Weeks Ago For Severe

I had a spinal mastectomy six weeks ago for severe spinal stenosis this was on my L4 vertebrae. The pain was in my right leg with numbness and loss of feeling in both feet and legs. Since my op I have been fine with only slight pain every so often in my right leg. The last three days I have had really bad pain right at the top of my leg and back and a couple of times when kneeling I got a striking pain up to the top of my leg. I also find out extremely painful when I put my foot down when walking. Could this be anything to do with my op?