Commentary

The authors provide a succinct report of 2 cases in which CaP cement was substituted for PMMA when managing 2 patients with vertebral osteoporotic compression fractures. The first patient was a 69-year-old woman with an L2 compression fracture, and the second patient was an 80-year-old man with an L1 compression fracture. Nevertheless, post-procedure radiographic studies documented heterotopic ossification around the CaP vertebrae and evidence of repeated collapse at these levels. In addition, patients developed subsequent vertebral compression fractures at other levels. The authors concluded that patients undergoing vertebroplasty with CaP should be closely followed as they are at risk for developing heterotopic ossification (HO), which may facilitate further vertebral collapse at treated levels, while other untreated levels remain susceptible to subsequent vertebral compression fractures. Heterotopic ossification seen after vertebroplasty with CaP may (1) not afford sufficient “initial stiffness” for the compressed vertebral body, thus fostering further vertebral collapse, and (2) heterotopic ossification may alter the “normal biomechanics” of the spine, sufficient to result in collapse at the treated as well as untreated levels. I think the authors should be applauded for bringing these adverse reactions to CaP vertebroplasty to our attention.