@rita9876 I'm glad your neurosurgeon drew diagrams for you so you can visualize what he proposes. With any hardware that is screwed into the spine, bone quality to hold it in place is very important. Every screw exerts some pressure in a particular direction and there is a risk that screws can loosen, pull out or break. Pedicle screws need precise placement to minimize that risk. I'm not saying that to scare you, but I've watched video presentations by surgeons at conferences taking about this and explaining revision surgeries. With an osteotomy, the bone fusion there has strength. It is worth asking if the osteotomy fusion strength is a better choice, essentially is the fused bone stronger than bone in general? Is that something that should be considered for deformity correction with osteoporosis?

When do you finish your Evenity treatment and then are able to schedule surgery? What would you need to do going forward after deformity surgery to maintain good bone quality and preserve the surgical correction?

You may also want to look at this post earlier in this discussion for a list of questions to ask a spine surgeon. Those came from a list I compiled of possible questions before my surgery.
https://connect.mayoclinic.org/comment/775287/