Kyphosis correction and height restoration effects of percutaneous vertebroplasty

BACKGROUND AND PURPOSE: Percutaneous vertebroplasty is known for its pain-relieving effect. Our purpose was to evaluate its effect on the kyphosis angle, wedge angle, and height of the fractured vertebral body. METHODS: We reviewed digital radiographs of 73 vertebral bodies in 53 patients before and after vertebroplasty. We measured the spinal kyphosis angle and the wedge angle of the fractured vertebral body. Ratios of the height of the anterior border, center, and posterior borders of the collapsed vertebra to the height at the posterior border of an adjacent normal vertebral body were measured. Gain from vertebroplasty and the restoration percentage (gain divided by loss) were calculated for each parameter. RESULTS:The kyphosis angle, wedge angle, anterior height, center height, and posterior height significantly improved after vertebroplasty. The mean reduction in the kyphosis angle was 4.3 degrees, and the wedge-angle reduction was 7.4 degrees. The mean wedge-angle reduction in fractured vertebral bodies containing gas was 10.2 degrees. Restoration percentages for the kyphosis angle and wedge angle were 19% and 44%, respectively. Gain in the height of the fractured vertebral bodies was 16.7% for the anterior border, 14% for the center, and 7% for the posterior border. Restoration percentages for the height of the vertebral body were 29% for the anterior border and 27% for the center. CONCLUSION: Vertebroplasty increases the height of the fractured vertebra and reduces the wedge and kyphosis angles. These effects are most remarkable in fractured vertebra containing gas.