Designs and Techniques That Improve the Pullout Strength of Pedicle Screws in Osteoporotic Vertebrae: Current Status

Figure 1

Effect of Screw Design on Pullout Strength. The percentages are with respect to a classic pedicle screw of otherwise similar dimensions TSRH: Texas Scottish Rite Hospital (conical screw), CD: Cotrel-Dubousset (conical screw), MM: Moss Miami (cylindrical screw), Cy/Cy: cylindrical thread with cylindrical core, Cy/Co: cylindrical thread with conical core, Co/Co: conical thread with conical core, V: standard thread, and Ti: titanium.