Patent ID: 8821548

Claim:
An apparatus, comprising: a first end unit having a first saddle configured to receive a first spinous process from adjacent spinous processes and a threaded outer surface; a second end unit having a second saddle configured to receive a second spinous process from the adjacent spinous processes and an unthreaded outer surface; an interbody unit disposed between the first end unit and the second end unit, the interbody unit defining a distance between the first saddle and the second saddle and having a first longitudinal axis; each saddle having a concave shape that has a lowest point and an opening, the openings facing in opposite directions and generally along a second axis defined by and extending through the lowest points of the two saddles; the first longitudinal axis being substantially coaxial with the second axis; the interbody unit comprising an inner surface defining a bore comprising a threaded portion and an unthreaded portion, the threaded outer surface engaging threads of the threaded portion and the unthreaded outer surface engaging the unthreaded portion; the first saddle having only two upwardly extending fork members and the second saddle having only two downwardly extending fork members, wherein each of the fork members has a substantially dull tip; wherein when the apparatus is disposed between the first and second spinous processes, each saddle extends through a sagittal plane defined by the first and second spinous processes; wherein the first and second end units are separate and distinct from one another.