The EVEREST Degenerative Spinal System is a top-loading
polyaxial pedicle screw system with the ability to accommodate
titanium and cobalt chrome rods of two different diameters. The
dual-lead thread pattern allows for faster insertion and
demonstrates increased pullout strength.  The mixed-metal
(Ti/CoCr) tulip minimized head splay and demonstrated
improved biomechanical performance when tested against an
all-titanium alloy screw.