I Had A Successful Anterior Spinal Fusion Back In 2010,

Question : I had a successful anterior spinal fusion back in 2010, two-level L4-S1, after years of devastating sciatica down my left leg. I have minimal hardware and each level only has two Medtronic titanium “thimbles” in parallel and artificial bone graft. The only lingering effect (not related to activity) was a somewhat permanent mild numbness on the left side of my big toe on the left foot. Before the surgery, I used to run, both short (track) and longer (not more than 4-5 miles at a time) workouts. After the surgery, any time I would run over half a mile, I would start to feel a little pain in the front of my left leg (my thought was that I was stressing the adjacent disk at L3-L4 with repetitive pounding) but I could continue to do the shorter stuff without any negative effects. As a result, I really don’t try to run any distances anymore but I do enjoy faster stuff on the track. Last week, though, I was sprinting a little harder than normal for a good HIIT workout. Everything felt fine during and immediately after. I took a shower about a half hour later, though, and then when I put my shoes on, both feet had a numbness to them on the sole near the toes, including near the big toe and second toe (the internet is telling me this is the medial plantar nerve). This was on both feet, but far more noticeable on the left foot (the side that my original sciatic problem was on). The thing is, I’m fused on the level that would seem to be related to this foot numbness, and it’s been fine for almost ten years. There were no other effects from that track workout last week other than this numbness in my feet (also, I’ve run harder and faster than that at other times without incident). Unfortunately, this numbness hasn’t subsided in a week. What could have happened? I can live with this as it is, though it’s pretty weird. I’m 47 and in decent shape. Thanks.