Abstract

Spinal fixations with pedicle screws are widely used nowadays in order to provide spine stability and correcting spinal deformity. The pullout strength of pedicle screws can be evaluated by means of pullout strength testing. This paper reviews recent experimental and finite element analysis evidence concerning the factors that affecting the pullout strength of pedicle screws in various bone materials. Cadaveric bones and synthetic foam blocks were used by researchers in the recent experiment. Types of screw, screw designs, insertion technique, bone mineral density and bone-screw interface have their own significant effects to the fixation strength and will be further discussed.

Key words: Spinal fixation, pedicle screws, pullout strength, cadaveric bones, synthetic foam blocks.