An expandable slide and lock stent (780) comprises a tubular member that can be expanded from a collapsed state to an expanded state. The tubular member comprises a first reversing helical backbone (782a), a second reversing helical backbone (782b) and at least one rail member (784a) extending from the first helical backbone in a circumferential direction. The second backbone has at least one engagement element configured to receive a rail member to form the tubular member. In some embodiments, the reversing helical backbones can comprise a plurality of discrete segments having a variable profile and/or wave form.