The Research Of The Applied Anatomy Of The Second Sacral Screw

Objctive: To provide anatomical basis for the placement of the second sacral screw.And tried to place the screw on the second sacral vertebra in three ways that had been reported,then to evalute the adventage and dangers of these three ways.Methods:â‘ The structure and contour of the the second sacral vertebra were observed on 30 dried adult sacrum specim- ens.â‘¡The nerves and vessels in front of the second sacral vertebra were observed on 15 adult cadaveric specimens .â‘¢Tried to place the screw on the the second sacral vertebra in the follow three ways 1.the medial way suggested by Miecovic 2.the way that placed the screw on the medial zone of the vertebra 3.the way that placed the screw on the lateral zone of the vertebra then to detected the length of the second sacral screw passing through the second sacral and to evaluate the advantages and disadvantages ,also the risks that damage the vessals and nerves of of the three ways.Results: there was enough volume of the second sacral speciemen for the screw placement.there were plentiful vessals andnerves in front of the second sacral vertebra.and ther is a safe zone for the exit of the screw in ront of the second sacral vertebra. As the three ways that has been reported placing the second sacral screw ,the way that screw placed on the the medial zone of the vertebra is better than the other two methords for the consideration of stability and security.