Pedicle screws are considered the Ôgold standardÕ in posterior spinal surgery for stabilizing fractures, promoting fusion and correcting spinal alignment. However, in the past 15 years there has been a rise in their most prevalent clinical failure, a loss of fixation at the bone-screw interface. Pedicle screw loosening was investigated by means of a surgeon survey, quantifying in vivo failure patterns, and by using pre-clinical testing methods to ascertain the most favorable screw positionings, augmentation techniques, and screw design features.