Patent ID: 7621950

Claim:
An expandable spacer, comprising: an axial tube having a surface provided along an initial contour, a proximal end, a distal end and a length, wherein, said surface defines a plurality of axially displaced slits, said plurality of slits defining at least two axially displaced extensions, such that when said tube is axially compressed, said extensions extend out of said initial contour and define a geometry of an expanded spacer; wherein when the tube is axially compressed, the at least two extensions have respective peaks farthest radially from the tube, the peaks of the extensions being separated from each other along the tube axis by portions of said surface situated radially inwards of said peaks in the axially compressed configuration; wherein said spacer is adapted for support of two vertebral plates on either side of the spacer, and wherein at least one of the extensions is designed to carry greater stress and has an increased strength over another extension, wherein a trans-axial cross-section diameter of said expanded geometry varies along an axis of said expanded geometry; and wherein said cross-section is rectangular and wherein said cross-section diameter increases along said expanded geometry axis.