Patent ID: 8435302

Claim:
An apparatus for distracting a disc space having an annulus, the apparatus comprising a spinal implant having: a pre-determined size sufficient to balance frictional fit in the disc space and elongation of the annulus; a top surface, a bottom surface, opposing lateral sides, and opposing anterior and posterior portions defining a substantially hollow center and a single vertical aperture defining a perimeter, the single vertical aperture (a) extending from the top surface to the bottom surface, (b) having a size and shape predetermined to maximize the surface area of the top surface and the bottom surface available proximate the anterior and posterior portions while maximizing both radiographic visualization and access to the substantially hollow center, and (c) defining a transverse rim of varying thickness; a roughened surface topography, without teeth, on at least a portion of the top surface, the bottom surface, or both the top and bottom surfaces surrounding the entire perimeter of the single vertical aperture and adapted to grip bone and inhibit migration of the implant; at least one sharp edge between the top and bottom surfaces and the anterior portion or the posterior portion to resist pullout; generally rounded and blunt intersections defined along the entire lengths between the top and bottom surfaces and the lateral sides, and either the top and bottom surfaces and the posterior portion or the top and bottom surfaces and the anterior portion, which do not comprise the at least one sharp edge; and at least one of the opposing anterior and posterior portions presenting a substantially flat impact face including an opening with an instrument retention feature.