Methods, systems, and mixtures deliver a bone cement to a void in a bone, and provide an expandable filler for expanding the volume of the bone cement. The void in the bone is accessed and a bone cement material is introduced into the void in the bone. An expandable filler is introduced into the void in the bone. The introduction of the filler can take place simultaneously with the introduction of the bone cement or before or after the bone cement. The expandable filler can be expanded and the bone cement can be allowed to set.