Ceramic fusion implants and compositions

Abstract

Bone graft substitute compositions are provided for promoting new bone growth and arthrodesis. The compositions include a carrier for controlled delivery of osteoinductive factors. In one embodiment, the carriers include a biphasic calcium phosphate ceramic having between about 2-40% hydroxyapatite and about 98-60% tricalcium phosphate by volume, and a calcium/phosphorous ratio of between about 1.50 to about 1.60. The invention also includes osteoinductive compositions including the carriers and an effective amount of a bone morphogenetic protein dispersed within the ceramic. The composition has a weight ratio of protein to ceramic of no more than about 1:200. In a specific embodiment, the weight ratio of protein to ceramic is between about 1:200 and about 1:2000. Spinal implants (10) are also provided which include a body (11) having a wall (12) sized for engagement within a space (S) between adjacent vertebrae (V) to maintain the space (S) and a confining matrix (13) for confining new bone growth to the body (11). The matrix (13) includes a biphasic calcium phosphate ceramic which degrades at a rate to provide calcium and phosphate for the new bone growth without reduced density of bone adjacent the space and an effective amount of a substantially pure osteogenic factor bound to the ceramic.

Dependencies are inferred from the claim text.