@kleerekoper I am not a user nor am I knowledgeable about the National Heath Service in the UK. But to the extent you can, keep asking more specialists. Something is clearly wrong and you need someone to evaluate it who will do more than just examine the imaging and sees nothing wrong.

Here in the US there is a fairly new and very active medical practice called sports medicine. Many of the practitioners are not surgeons. If the imaging looks good, maybe your best bet would be to find a specialist in this area who is NOT a surgeon and see what she says. To my layman's eye it certainly looks like something involving nerves, muscles or bones.