Patent ID: 8518118

Claim:
A spinal prosthesis configured for insertion between two adjacent vertebrae, a first vertebra and a second vertebra, comprising: an implant strip including a lateral dimension extending from a first lateral side portion to a second lateral side portion, and wherein the implant strip includes a longitudinal dimension extending down a length of the implant strip; wherein the first lateral side portion of the implant strip is configured to engage the first vertebra and wherein the second lateral side portion of the implant strip is configured to engage the second vertebra; wherein a first longitudinal portion of the implant strip forms a first inner coil, and wherein a second longitudinal portion of the implant strip forms a second outer coil, wherein the second outer coil is spaced radially outward of the first inner coil; wherein the first lateral side portion and the second lateral side portion comprise a first portion; wherein a second portion is disposed between the first lateral side portion and the second lateral side portion, and separates the first lateral side portion from the second lateral side portion; wherein the first lateral side portion has a first outer longitudinal edge and a first inner longitudinal edge and wherein the second lateral side portion has a second outer longitudinal edge and a second inner longitudinal edge; wherein the first portion comprises a first material and the second portion comprises a second material, wherein the first material is different from the second material; wherein the first inner longitudinal edge comprises at least one of a perforated edge, a toothed edge, and a roughed edge; wherein the second portion encases the at least one of the perforated edge, the toothed edge, and the roughed edge; and wherein the second portion deflects before the first portion under an axial load applied to the implant strip.