A modular system for fixation of a spinous process includes at least one pair of blocks shaped so as to engage a particular segment of the spinous process and arranged on opposing sides of the spinous process. Each block has a surface facing the portion of the spinous process to be engaged, the surface having an array of sharp spikes to penetrate the spinous process when so engaged. Two rods arranged parallel to the spinous process are provided to connect the at least one pair of blocks and therefore stabilize multiple segments of the spinous process. Each block includes an aperture within a central portion of the block and shaped so as to slidably receive one of the rods. Set screws are provided so as to securely position the block along the length of the rod.
