3 2002 and entitled bio compatible polymeric materials and pct publication wo 02 00270 a1 dated jan 3 2002 and entitled bio compatible polymeric materials other materials such as bionate u00ae polycarbonate urethane available from the polymer technology group berkeley calif may also be appropriate because of the good oxidative stability biocompatibility mechanical strength and abrasion resistance other thermoplastic materials and other high molecular weight polymers can be used as mentioned above each spacer 102 can be connected with a pin 110 that adjustably connects the first plate 104 a with the second plate 104 b in one embodiment each plate 104 a b has three slots 106 spaced and sized such that the slots 106 span approximately the width of the gap between the associated adjacent spinous processes when a patient is standing up the length of the slots 106 should allow for necessary adjustment of the spacers 102 so that the anatomy of the adjacent spinous processes can be accommodated with the spinous processes immobilized between the spacers 102 in the system 100 shown in fig1 the middle of three slots 106 is sized larger than the slots 106 on either end of the plates however in other embodiments the slots 106 can be sized relative to one another based on the vertebral bodies that are intended to be immobilized as described above a pin 110 can be fitted into a slot 106 in each plate 104 a b the width of the slot 106 allows the pin 110 to be optimally positioned within the gap between spinous processes while still being fixable to the plates.