Anterior spinal instrumentation and method for implantation and revision

Patent Number: 5683391, issued on 1997/11/04    
Applied on 1995/07/07
Inventor(s): Lawrence M Boyd
Assignee: Danek Medical, Inc.

Abstract: A system and method for anterior fixation of the spine utilizes a cylindrical implant engaged in the intradiscal space at the cephalad and caudal ends of the construct. The implants are cylindrical fusion devices (10) filled with bone material to promote bone ingrowth and fusion of the disc space. An attachment member (40) is connected to each of the fusion devices (10) and bone screws (30) having similar attachment members (33) are engaged in the vertebral bodies of the intermediate vertebrae. A spinal rod (50) is connected to each of the attachment members using an eyebolt assembly (53, 54, 55). In a further inventive method, a revision of the construct is achieved by removing the fusion devices. Each fusion device is engaged by an elongated guide member (62) over which a cylindrical trephine (70) is advanced. The trephine (70) has an inner diameter larger than the diameter of the fusion implant and includes cutting teeth (72) for extracting a core (84) of bone material around the fusion implant. The trephine (70) and guide member (62) are removed along with the bone core (84) containing the fusion implant (10). The trephine (70) is also used to extract a bone dowel from a solid bone mass to be inserted into the space left by the removed bone core (84).