thank you for you're very detailed and painful to read message...Im horrified and angry for you....and, perhaps myself as I, too have had posterior cervical spinal surgery, (c2-c6 or 7), 2019 due to spinal compression. The morning after surgery I could not hold a fork to eat by breakfast plus I had this strange uncomfortable feeling that felt like rushing water/fire down my arms and out my fingers. "Mylopathy", my surgeon said. So, I have been contending with the resulting whole body numbness but most especially my arms and hands.
Within the last few years I've noticed a minor twinge of pain in back of my neck so I saw another neurosurgeon to have an X-ray when he found that I had a loose screw from, what I call, my "cage". He did not want to proceed but did not indicate it could become that serious an issue. I feel the screw has moved as what used to be minor pain is now quite sudden and sharp pain in my left shoulder when I move my head to the right. I have hesitated to see a neurosurgeon again as I would not want another such surgery. Your posting has encouraged to see a neurosurgeon and I'll post about the outcome afterwards.