Thank you for your thoughts and comments, windyshores. I had wondered about the low CTX myself but felt i didn't have much choice but to carry on with the Alendronate for at least a year to prevent any Prolia rebound. I have only read about long-term use of Prolia possibly causing MVFs or ATFs but not normal spinal compression fractures so I don't know if Prolia (or Alendronate) itself could be the cause. It is also probably unlikely to be caused by Prolia rebound as the indication there would be very high CTX.

My immediate decision now is whether i should stop my Alendronate now (after having completed 1 year since the skipped Prolia shot) to allow CTX to rise to assist in healing? Unfortunately, my PCP has little knowledge about osteoporosis treatment - he started me on Prolia without any calcium or D3 tests or taking any baseline numbers and he didn't know about the Prolia rebound danger.