Synthes Synapse SD Drill Guide, Part Number SD389.477, Lot Number 6913900 || Indicated for Hooks, Plate/Rods, Rods and Screws when intended to promote fusion of the cervical spine fusion of the cervical spine and occipitocervical junction (occiput-T3), the plate/rod, rod, hook and screw (3.2 mm cortex) components of the Synthes Cervifix; Axon and Synapse Systems are indicated for the following: -Degenerative Disk Disease (DDD) (defined as neck pain of discogenic origin with degeneration of the disc as confirmed by patient history and radiographic studies); -Spondylolisthesis; -Spinal Stenosis; -Fracture/dislocation; -Atlantoaxial fracture with instability; -Occipitocervical dislocation; -Revision of previous cervical spine surgery; and -Tumo