Fig. 2.

Lateral plain films of a 69-year-old woman with an L2 compression fracture. a The initial lateral plain X-ray showed an acute compression fracture and air cleft sign in the L2 vertebral body. b Immediate postoperative lateral plain X-ray showed well-deposited CaP cement. c Three months after the vertebroplasty, recollapse and heterotopic ossification occurred (arrow) and the injected CaP was reabsorbed. d Thirty months after the vertebroplasty, the heterotopic ossification was condensed and osteogenesis had developed in the vertebral body