I had L4-S1 fusion and know exactly the feeling you refer to depending which side I lean which inner thigh went numb also radiating to the testicles, I’ve been told it’s not the lumbar causing it. I can rub my hand across he incision and the pain starts. Same way with Anal pain, I’m being treated by a pelvic therapist which I thought was for women not men who works internally she has been working on the nerves in their and getting the tailbone lined back up it helps and you can sure tell when the tailbones misaligned. I’m starting to be able to sleep on my back but wake up with toes numb and sometimes hands. I’m waiting until April to see the surgeon hoping he listens this time and finds out what’s wrong my pain is getting worse