Patent ID: 7758644

Claim:
A system for intravertebral reduction, comprising: a delivery instrument including a radially expandable element along an outside surface of a distal portion thereof; an expandable device including a cavity, the expandable device being removably mountable to the expandable element with the expandable element in the cavity and each of the expandable device and the expandable element in an unexpanded condition, the expandable device including an external surface and an internal surface, said external surface having a first portion and a second portion movable away from one another upon expansion of the expandable element, the first portion defining a first linear outer surface and a second linear outer surface, the second portion defining a third linear outer surface and a fourth linear outer surface, said internal surface facing said cavity, wherein the expandable device is deliverable to an intravertebral space in the unexpanded condition and thereafter expandable with expansion of the expandable element to compress cancellous bone in the intravertebral space, wherein the first linear outer surface and the second linear outer surface define a first step, and the third linear outer surface and the fourth linear outer surface define a second step, such that the expandable device has a stepped cross-section configuration and such that in an expanded condition the first linear outer surface and the third linear outer surface are separated by a first height and the second linear outer surface and the fourth linear outer surface are separated by a second height greater than the first height; and bone filler material positioned in the cavity between the first and second portions.