Patent ID: 7591852
Filing Date: 2009-09-22
Classification: A61F

Abstract:
1. A cage assembly adapted to be implanted in a spinal column for treating degenerative or ruptured discs and replacing damaged vertebral bodies, said assembly comprising a rigid cage formed in an annular configuration of a biologically inert material, said cage having opposed upper and lower surfaces extending about perimeter portions thereof; an annular side wall extending between said surfaces; a plurality of raised ridges projecting outwardly from each one of said upper and lower surfaces for engaging the spinal column and securing the assembly therein and disposed at offset angles with respect to each other; wherein at least one of said surfaces of said cage defines a plurality of indexing members thereon and wherein said cage assembly includes at least one spacing element adapted to be secured to said one cage for the stacked attachment of said cage with a second cage, said indexing members cooperating with portions of said spacing element for axially aligning said spacing element with said one cage, said spacing element is configured to have flat upper and lower surfaces that do not include said raised ridges and is further configured to be spaced apart from respective upper and lower surfaces of said cage and said second cage when said cage assembly is implanted into the spinal column; a plurality of spaced apertures in said side wall for use in positioning said cage in the spinal column in a desired angular orientation; and a pair of axially aligned openings extending axially through said cage, said openings being adapted to be packed with bone graft material to expedite the fusion of the cage assembly in the spinal column.