A persuader instrument for advancing a fixation rod into a vertebral implant includes a housing and at least one arm. The at least one arm can include detents for detachable connection to the vertebral implant. The persuader instrument can also include a shaft coupled to an anchor. The anchor can include a fixation rod engagement surface. The shaft can be axially displaceable through the housing to axially displace the anchor and a rod engaged by the anchor. The persuader instrument can further include an auto-locking ratchet assembly in releasable engagement with the shaft. The auto-locking ratchet assembly can control axial displacement of the shaft through the longitudinal passage of the housing.