Fig. 1

Puncture and injection procedure. a The location of point A on the anteroposterior film (the lateral border of the pedicle). b The location of point A on the lateral film. c The location of point B on the anteroposterior film (the midpoint of the connecting line of point A and the medial border of the pedicle). d The location of point B on the lateral film (the midpoint of the connecting line of point A and the posterior margin of vertebral body). e The location of point C on the anteroposterior film (the medial border of the pedicle). f The location of point C on the lateral film (the intersection of the posterior margin of the vertebral body and the extension line of the connecting line between points A and B). g Cement was injected when the needle reached the posterior area of the anterior wall of vertebral body. h The needle was retracted and cement injected. i The needle was retracted to the front of the pedicles to continue cement injection. j Dispersion of bone cement on the anteroposterior film. k The needle was retracted to point B, and then, the angle was adjusted to be advanced forward to point C. l The needle core was pulled out and prepared to connect the syringes. m Same as g. n Same as h. o Same as i. p Dispersion of the bone cement on the anteroposterior film