Fig. 2

A graphic of the second puncture procedure. a The cement is restricted to the cleft (there is no extra-cleft dispersion) when initial cement injection through the cannula is completed. b The cement introducer is removed and replaced with the inner stylet (solid line). The needle is then retracted to the pedicle entry point until the tip can be redirected (dotted line). c At the same pedicle entry point as before, the cephalocaudal needle direction is changed to that of the region that is not filled with cement, but the abduction angle is unchanged (the dotted and solid lines show the initial and redirected needle positions, respectively). d The redirected needle is advanced to the intravertebral region that lacks cement