US Patent 7608096 Posterior pedicle screw and plate system and methods

An apparatus is provided for correcting spinal abnormalities, and particularly for providing compression and/or distraction of vertebrae without additional tools or instrumentation. A plate member is provided with a plurality of slots, one of which has a sloped internal edge or surface. The plate is anchored to one vertebra by a first anchor, and a second anchor is then placed through the slot with the sloped internal edge or surface and tightened. Such tightening causes the plate to move with respect to the tightened anchor, and thus to transmit compression or distraction to the vertebrae. The apparatus is particularly useful in minimally-invasive surgeries but can also be used in more traditional open surgeries.