Modular spinal prosthesis having one of both of adaptable and configurable components are provided. The modular spinal prosthesis described herein provide an artificial articular configuration to replace damaged, worn or otherwise removed spinal facet elements. The prosthesis can include a crossbar having first and second ends. A first caudal prosthesis can be attached to the first end of the crossbar, while a second caudal prosthesis can be attached to the second end of the crossbar. A first crossbar mount can be positioned on the crossbar near the first caudal prosthesis, while a second crossbar mount can be positioned on the crossbar near the second caudal prosthesis. A first cephalad prosthesis can extend from the first crossbar mount, while a second cephalad prosthesis can extend from the second crossbar mount.