Prostheses, systems, and methods are provided for replacement of natural facet joints between adjacent vertebrae with vertebral prostheses. A portion of the vertebral prosthesis includes anti-rotation and/or anti-pullout elements to prevent or reduce prosthesis fastener rotation or pull out as a result of torques applied to the prosthesis. Various tools and methods aid the process of surgically adding the vertebral prosthesis to a patient's vertebra.
