Fig. 1.
Example distraction of L5–S1 disk space resulting from in situ expansion of an interbody cage. Top left: L5–S1 disk space prior to surgery. Top right: Implantation of the expandable polyaryl-ether-ether-ketone (PEEK) spacer prior to expansion. Bottom left: In situ expansion of the PEEK spacer. Bottom right: The end of the operation.