Kyphoplasty

The balloon expands the collapsed vertebra before it is filled, aiming to recover part of the lost height and reduce the wedging. It makes sense when the fracture is contributing to the deformity of the back, not only when it hurts.

When the fracture is recent and the wedging is significant. It only manages to expand the vertebra in recent fractures; in older ones it offers no advantage over vertebroplasty, and then there is no reason to complicate the procedure.

This is not a decision to leave sitting. Doing it early dramatically shortens the time spent in pain and with restricted mobility, and the balloon only expands the vertebra while the fracture is recent: waiting can rule out the very part of the technique that justifies it.

Probably not. Small collapses that do not deform the back can be treated with a brace and pain relief, or with cement if the goal is to shorten the time in pain. The balloon is justified by the wedging, and without wedging it adds nothing.