Hello, I am 13 months post-op TLIF with instrumentation and disc spacer at L4-5. Had spondylolisthesis with severe stenosis and herniated L4-5 disc. About 3 months post op, last July I noticed a twinge of pain behind my left knee while I was walking. It was so bad I had to stop my walk. Ever since, it comes and goes randomly, whether I am on my feet or at rest. I experience the same pain on top of foot between 2nd and 3rd toe. I also experience pain on top of foot just in front of the ankle and sometimes the side of ankles. I think it is nerve pain as I have not had any injuries, no illness either. I have been to many doctors trying to determine the source of this pain. I went to the vein clinic and was scanned for blockages or varicose veins....negative. I had a complete workup by a Rheumatologist....negative. I went to a podiatrist....nothing of note. Endocrinologist...negative. Yesterday I had a nerve conduction study...negative!! No entrapment or nerve damage. But the doctor told me the pain I am experiencing corresponds to the Peroneal nerve which branches off the Sciatic nerve, affects the knee and upper foot down to toes. He said that it originates from the L4 L5 level. This makes me think this is somehow related to the TLIF and wondered if any one here in the community has had similar symptoms following fusion? I have noticed the behind the knee pain a lot when I am seated in my car. When in my vehicle, my knees are slightly higher than my hips. The pain is not debilitating, but it was a little disconcerting going to several types of medical specialists and not one being able to tell me what it could be.