US Patent 8182518 Static and dynamic cervical plates and cervical plate constructs

A cervical bone plate includes a graft window that allows access to and/or visualization of a bone graft area of the cervical spine after attachment of the present cervical plate to the vertebrae. The window is preferably, but not necessarily, sized for maximum exposure of the graft area and/or the vertebral body without compromising plate strength, particularly with respect to federal standards for such devices. The window is centrally positioned on the plate and is sized to provide alignment of the plate onto the vertebrae at the base of the vertebra fastener or screw holes of the plate. In a dynamic form of this cervical bone plate, the graft window expands and contracts with respective expansion and contraction of the dynamic plate after attachment to the vertebrae (i.e. “dynamizes”). In another form, a three-component dynamic bone plate is configured such that a middle component accepts an identical end component at both ends of the middle component. The end component is a 180° interchangeable part. The middle component and the end component have cooperating configurations and complementarily configured grooves that allow sliding movement between the middle component and the end components. A two-pillar construction provides a central window.