An anterior cervical plate system is provided. The plate is configured to receive bone screws for attachment to and immobilization of adjacent vertebrae of the spine. The system includes a lock configured to prevent the bone screws from backing out of the plate. The lock includes at least one blocking surface that is movable between a blocked configuration preventing the bone screw from backing out and an unblocked configuration allowing passage of the bone screw. The lock achieves a blocked position in a rotation of less than 90 degrees while maintaining or increasing a low-profile.
