Modular pedicle screw assembly

A modular pedicle screw assembly for use in spine surgery, comprising:

• a shank having an insertion end configured for insertion into a vertebra, a connector end, and bone-engaging threads formed therebetween, the connector end having a conical outer surface and an inner driver receptacle configured to receive a driver tool for rotation of the shank;
• a spherical collet securable to the connector end, the collet having a plurality of compression slits permitting compression of the collet for locking engagement with the connector end, the collet further having an open upper portion and an open lower portion to permit passage of the driver tool to the driver receptacle;
• a split ring positioned over the collet, the split ring having a chamfered lower inner edge;
• a cap having a lower surface conforming to a shape of the collet, said cap positioned within the split ring;
• a saddle coupled to the collet, the saddle having a U-shaped channel defining a lower section configured to receive a rod member and a threaded upper section configured to receive a set screw;
• wherein said shank is anchored to said saddle for receipt of a rod member, whereby tightening of the set screw compresses the cap and the split ring to lock the rod member and saddle in a fixed position relative to the shank.