A system (10) and associated method are provided for mechanically fixating a region of a skull to a portion of a spine. A plate (20) is provided to contact a region of the skull and be secured thereto. A spinal rod (22) is configured to extend from a location adjacent the plate (20) to a location adjacent at least one vertebra (30). A variable connection (24) is provided to secure the rod (22) to the plate (20). The variable connection (24) has a first mode wherein the relative position of the rod (22) to the plate (20) can be adjusted and a second mode wherein the relative position of the rod (22) to the plate (20) is locked at a particular value selected to maintain a desired curvature of the spine.