Crossbar spinal prosthesis having a modular design and systems for treating spinal pathologies

An adaptable spinal facet joint prosthesis system, comprising:

• a pedicle fixation element having a distal end configured to engage bone;
• a laminar fixation element having a distal end configured to engage bone;
• a crossbar having a first end and a second end;
• a facet joint bearing surface having a location adaptable with respect to at least one of the pedicle fixation element and the laminar fixation element, wherein the facet joint bearing surface is disposed at the first and second ends of the crossbar, and wherein at least one of the pedicle fixation element and the laminar fixation element includes a bearing surface configured to receive the facet joint bearing surface
• wherein a portion of the pedicle fixation element and the laminar fixation element limits the movement of the crossbar, and
• a dual clamp housing having a first opening for receiving a first cephalad prosthesis and a second opening for receiving the crossbar, wherein a crossbar lock includes a single fastener that is received in the first opening and urges the dual clamp housing to clamp down on the first cephalad prosthesis and on the crossbar.