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Fig. 31.6. AP a and lateral b X-rays of a patient following posterior cervical wiring. The wires are encircled around the spinous processes of C6 and C7. This fixation configuration supplements the posterior extension function of the interspinous ligament, but has limited translational stability.

a b triple-wire technique, where struts of bone are wired to the spinous processes over the motion segments, improves translational stability [22]. Besides the biomechanical problems with posterior element wiring, the frequent need to undertake decompression at the time of fixation/fusion requires removal of the spinous processes and laminae, making them unavailable for such wiring techniques. Based upon the limitations of midline wiring, lateral mass fixation procedures emerged.

Facet wiring, although somewhat technically demanding, if it can be accomplished, is the most stable wiring technique available. It is not dependent upon the integrity of the laminae or the spinous processes. The technique involves making holes through the inferior aspect of the lateral mass and facet of the adjacent vertebrae and passing wires through these holes and up through the facet joint space [23].

Lateral mass plating techniques were developed approximately 25 years ago. The procedure involves placement of a screw through the lateral mass of the vertebrae. The entry point of the screw is in the anatomical center of the lateral mass. The screw direction is oriented superior and lateral in the lateral mass to avoid the nerve root and vertebral artery, respectively. With the plates secured to the posterior aspect of the lateral masses by the lateral mass screws, both extensor tension band and transla-tional stability across the motion segment are enhanced. The initial lateral mass-plating techniques involved semi-rigid devices, where the screw head was not rigidly fixed to the plate (Fig. 31.7). The newer-generation devices have connecting links which secure the screw heads to rods in a rigid manner. This increases the stability of the fixation.

Anterior fusion techniques involve the use of bone graft which is at least partially composed of cortical bone, to allow for structural stability of the fused segment in compression. The size of the graft is dependent upon the extent of disk and/or bone removal required for the decompression. An interbody graft is used following diskectomy and a more lengthy cortical cancellous strut graft is used for vertebral body replacement following vertebrectomies. The use of an anterior cervical plate is a frequent adjunct to the anterior bone graft. Much attention has been directed towards anterior fusion techniques with regard to factors influencing

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