Fig. 1

Diagrams of the flexible bone cement injection device and its mode of operation. a Flexible cement injector, showing its in-built curved tip. b Insertion of the flexible cement injector through the introducer. c A first mark on the flexible injector cannula identifies the point where the tip exits the introducer. d Using gentle back-and-forth rotation, the bone cement injector is advanced into the vertebral body. e On reaching the second mark on the flexible injection cannula, the tip of the cannula is located at the centre of the vertebral body. f When reaching the second scale at the end of the cement injector, it indicates that the cement injector head is on the opposite side of the vertebral body. g The central wire is removed. h The bone cement is first injected on the contralateral side of the vertebral body. i Approximately 2 ml of bone cement is used at this first point. j The injector is retracted to the second mark and a further 2-ml bone cement is injected. k The injector is retracted to the first mark and a further 2-ml bone cement is injected