This just started happening to me a few weeks ago. It is always on the right outter top of leg and up into the buttocks. I do have several spinal problems and I have figured it was related. I have herniation at l34, failed fusion l4-5, spony, sciatica and OA. I wish I could help you more, but I will keep reading in hopes to learn something myself. If I learn anything, I'll keep you posted.
Lorie