Patent ID: 7585324

Claim:
A cervical intervertebral stabilizer for a cervical region of a spine, comprising: a first surface operable to engage an endplate of a first vertebral bone of a spine; a second surface spaced apart from the first surface and operable to engage an endplate of an adjacent second vertebral bone of the spine; and a spring element including a substantially solid exterior wall forming a hollow passage between the first and second surfaces, the solid exterior wall including at least one helical slit therethrough forming a plurality of annular circumferential, overlapping helical coils, the spring element being disposed between the first and second surfaces and operable to provide reactive force in response to compression loads from the first and second vertebral bones, wherein at least some diameters of respective turns of the helical coils differ such that those of the turns having larger diameters are disposed towards the first and second surfaces and those of the turns having smaller diameters are centrally located between the turns having larger diameters, and diameters of the hollow passage between the first and second surfaces vary such that larger diameters are disposed towards the first and second surfaces and smaller diameters are centrally located.