Distraction plate system

A plate system for distracting and fixating vertebral bodies comprising

• a) a biocompatible plate comprising a top surface, a bottom surface configured to confront a vertebral body and at least two generally circular holes, each hole comprising a length extending from the top surface to the bottom surface, a diameter, a circumference, and a plurality of teeth spaced evenly about the circumference;
• b) at least two biocompatible distraction screws, each biocompatible distraction screw comprising an expandable head, the expandable head generally circular in shape and comprising a circumference, a diameter and a plurality of teeth spaced evenly about the circumference and configured to engage the teeth of a generally circular hole of the biocompatible plate, a shank comprising threads located on an exterior surface of the shank, a length extending from the head to the shank, and a generally circular bore comprising a top end located in the head, a bottom end located in the shank, and threads spaced about the bore;
• and
• c) at least two biocompatible fixating screws, each biocompatible fixating screw comprising a head and a shank comprising threads located on an exterior surface of the shank, each shank of each biocompatible fixating screw configured to be received in a generally circular bore and mate with the threads of the generally circular bore,
• wherein the expandable heads have a radially collapsed state in which the circumferences of the expandable heads are less than the circumferences of the generally circular holes and the diameters of the expandable heads are less than the diameters of the generally circular holes,
• wherein the expandable heads have a radially expanded state in which the circumferences of the expandable heads are substantially equal to the circumferences of the generally circular holes and the diameters of the expandable heads are substantially equal to the diameters of the generally circular holes, and
• further wherein insertion of the fixating screws into the distraction screws causes the distraction screw heads to move from the radially collapsed state to the radially expanded state.