Patent ID: 7833271

Claim:
A human intervertebral fusion spacer, comprising: a body comprising a block of bioabsorbable material selected to promote bone growth and having a compressive strength at least as great as the compressive strength of an intact vertebra, the body defining a central opening fully open at and extending from a cranial aspect of the body towards a caudal aspect of the body and fully surrounded on lateral, anterior and posterior sides by the body, wherein the body is shaped to conform to a general shape of outer surfaces of a vertebra; and an insert comprising a single solid block of bioabsorbable material having a shape and length complementary to the shape and length of the opening in the body, wherein the body has a mechanical crush resistance that is greater than the mechanical crush resistance of the insert, wherein the insert has a plurality of man-made passageways extending from a top surface of the insert to a bottom surface of the insert, wherein the insert has at least one man-made passage that extends through a side surface of the insert and intersects with one or more of the plurality of man-made passageways, wherein the plurality of man-made passageways and the at least one man-made passage are sized to promote bone growth that fuses adjacent vertebrae together when the insert is positioned in the opening of the body and the insert and the body are placed between the adjacent vertebrae and are sized to allow bone growth promoting material to be inserted in the passageways, wherein the body is shaped so that a portion of the opening open to the cranial aspect of the body is sufficiently large to receive the insert and a portion the opening more proximate to the caudal aspect of the body is smaller than a cross-section of the insert to inhibit the insert from passing out the opening through the caudal aspect of the body, wherein the plurality of man-made passageways and the at least one man-made passage are drilled through-holes containing a bone growth promoting material therein.