US Patent 8002809 Dynamic cervical plate

A dynamic cervical plate has a ratchet and pawl mechanism that allows the cervical plate to post operatively shorten the length of the plate and maintain compression between adjacent vertebrae. The plate has an elongated shaft with grooves on one surface and a groove along each longitudinal edge. A lateral bar is attached on one end of the shaft. The bar has screw holes for connecting with the head of a spinal screw. Another lateral bar is slidably engaged in the longitudinal grooves along the shaft and has a spring clip acting as a pawl with the grooves on the shaft. The sliding bar has screw holes on each side of the shaft. The clip is configured to span the screw holes to prevent screws from backing out of the holes.