– General Aspects of Spinal Implants:
Spinal implants have been manufactured from titanium alloys and polyetheretherketone (PEEK). Cobalt-chromium (CoCr) alloys have also been utilized in one type of spinal implants (disc replacements).
– Spinal implants are used to stabilize the unstable spine caused by trauma or by slipped vertebrae (spondylolisthesis) originating from degenerative intervertebral disks. Surgical stabilization can be achieved from either the anterior or posterior approach. From the anterior approach, adjacent vertebral bodies are connected and fixed by a plate or rods with screws which are inserted into the vertebral bodies. To stabilize the spine from the posterior, rods connected with pedicle screws are used. A new navigation system has become clinically accepted, as it is able to assist a surgeon to identify the screw insertion sites and to find a direction in which screws should be inserted