Fig. 3From: Pullout strength of different pedicle screws after primary and revision insertion: an in vitro study on polyurethane foamA) First sequence: Primary insertion and pullout test using the same screw; B) Second sequence: Primary insertion of a 6.0 mm diameter screw, followed by insertion of either a larger 6.5 mm screw of the same design or a 6.0 mm screw of a different designBack to article page