Significance of dynamic mobility in restoring vertebral body height in vertebroplasty

Many authors have reported the increase in vertebral body height after vertebroplasty. However, McKiernan et al demonstrated dynamic mobility in patients who underwent vertebroplasty and concluded that any article that claims vertebral height restoration must control for the dynamic mobility of fractured vertebrae. The purpose of this study was to compare prevertebroplasty (supine cross-table with a bolster beneath) with postvertebroplasty vertebral body height to find out whether vertebroplasty itself really increases the vertebral height.

From July 2005 to July 2010, 102 consecutive patients with 132 VCFs underwent vertebroplasty at our institution. The indications for vertebroplasty were severe pain that was not responsive to medical treatment, and MR imaging-confirmed edematous lesions. Prevertebroplasty (supine cross-table with bolster beneath) lateral radiographs were compared with postvertebroplasty radiographs to evaluate the height change in vertebroplasty. Kyphotic angle and anterior vertebral body height were measured.

The patients ranged in age from 62 to 90 years. There were 16 men and 86 women. The difference in the kyphotic angle between supine cross-table with bolster and postvertebroplasty was -0.49 ± 3.59° (range, -9°-16°), which was not statistically significant (P = 0.124). The difference in the anterior vertebral body height between supine cross-table with bolster and postvertebroplasty was 0.84 ± 3.01 mm (range, -7.91-8.81 mm), which was statistically significant (P = .002).

The restoration of vertebral body height in vertebroplasty seems to be mostly due to the dynamic mobility of fractured vertebrae; vertebroplasty itself does not contribute much to the restoration of vertebral height.