Because of the rebound, with a drop in bone density and increase in fracture risk when you stop. That's what he said. Of course you can go on Reclast afterward but similar risk with long term effect on bone turnover.

Not everyone experiences avascularity in response to bisphosphonates. Everyone who takes Prolia will experience a flood of osteoclasts after stopping the drug. Because of the way Prolia works. Everyone who stops Prolia should take an antiresorptive. Doctors, at stride in their careers when Prolia was first hailed, have seen the damage that can ensue because they trusted the literature and prescribed the drug. These are the many who will not prescribe Prolia.
My comment is a little out of turn, I apologize.