Patent ID: 7377923

Claim:
A variable angle spinal screw assembly adapted to be secured to a vertebrae for providing an adjustable securement of a fixation rod across at least two vertebrae, said assembly comprising: a pedicle screw having a substantially spherical head portion, a threaded shaft portion and a tool engagement surface defined by the head portion for use in driving the screw into a vertebrae; a body member for receiving said head portion of said screw therein and defining an opening in an inner end thereof for the extension of said shaft portion of the screw therethrough, a pair of opposed parallel slots therein for receiving a portion of a fixation rod therebetween, a curvilinear interior surface disposed about said opening for abutting and mating with said substantially spherical head portion of said screw so as to allow variable angular movement of said body member with respect to said pedicle screw while maintaining said interior surface of said body member in mating contact with said head portion of said screw; a locking cap releasably securable within said body member such that said cap bears against the portion of a fixation rod disposed between said slots to secure the rod within said assembly; and a keyed interface between said pedicle screw and said body member whereby said pedicle screw can be inserted into a vertebrae and said body member subsequently disposed about said substantially spherical head portion of said screw such that said head portion abuts and mates with said curvilinear interior surface of said body member to provide said variable angular movement of said body member with respect to said screw; wherein said keyed interface comprises a first threaded surface in said body member about said opening in said inner end thereof and a second threaded surface on said head portion of said screw, said first threaded surface being adapted to threadably engage said second threaded surface such that said screw can be inserted into a vertebrae and said body member threaded onto and over said head portion of said screw to position said curvilinear interior surface of said body member such that said interior surface can abut and mate with said body portion.