Boy- there is a lot to cover here. I’ll try to be as brief as I can.
You have a fear of spinal surgery that may be warranted after you have listened to various patients troubles but as in anything, spine surgery included, you must weigh the fear against the actual reality.
You have an instability of C1-2. The “head” of C2 has been sheared off (the dens) and your neck is unstable (os odontoidium). C1 now moves too much and has put the cord in jeopardy. However, you have a fear of a stroke with surgery to correct this instability.
Yes, the fusion surgery you mention is uncommon. I personally have performed only about 25 of these C1-2 fusions compared to the thousands of other fusions I have performed. The reason is that this condition is very uncommon. Stroke is possible (the vertebral artery is close by) but I have never seen that problem and even with discussions with all of my colleagues, I have never heard of that complication
You mention you don’t want your “quality of life” to suffer for fear of a stroke but I have to point out that by your report, you have already developed a spinal cord injury from your instability; “had an accident that rendered me unable to walk straight due to poor balance, dizziness…”.
BMP (bone morphogenic protein) is not the terrible evil that you think it is. I use it for many fusions and it is a very useful tool to allow fusion to occur. The posterior C1-2 or C1-3 surgery that you have had proposed is a perfect example of where this protein would be most useful. You have read one study that purports increased risk but there is a new study that refutes this and I personally have seen no increased risk.
Your understanding of fusion is incorrect. Most times, a solid fusion will eliminate pain and not cause it.
Prolotherapy is not the panacea that you purport. First, the indications have to be appropriate. Prolotherapy injects a toxic substance that is designed to injure local tissue leading to scar formation response. Many reported indications in my opinion are not appropriate. You generally do not want to destroy normal ligaments, tendons or muscles to “treat them”. Injecting these toxic substances into the upper neck is strictly contraindicated. What happens if this substance accidentally infiltrates into the spinal canal? Injury to the cord would be irreversible. Even infiltration around the greater occipital nerve would leave your head numb and possibly painful.
Stability of the C1-2 level cannot be gained by prolotherapy. This is NOT a ligament problem but a fracture of a bone that did not and will not heal. If you truly have what you reported here, you need a fusion of this level. If you re-injure the cord in this area, paralysis or death can be the result. I highly encourage you to face your fears of surgery and visit a spine surgeon soon.