Figure 4From: Pullout strength of pedicle screws with cement augmentation in severe osteoporosis: A comparative study between cannulated screws with cement injection and solid screws with cement pre-filling The average ultimate pullout strength of fully inserted conical and cylindrical pedicle screws with various screw fixation techniques. Regardless of the screw outer geometry (conical or cylindrical), solid screws with retrograde cement pre-filling exhibited the highest pullout strength, whereas solid screws without cement augmentation exhibited the lowest pullout strength (p < 0.001).Back to article page