Percutaneous vertebral augmentation: an elevation in adjacent-level fracture risk in kyphoplasty as compared with vertebroplasty.

BACKGROUND CONTEXT Osteoporotic vertebral compression fractures (VCFs) are being increasingly treated with minimally invasive bone augmentation techniques such as kyphoplasty and vertebroplasty. Both are reported to be an effective means of pain relief; however, there may be an increased risk of developing subsequent VCFs after such procedures. PURPOSE The purpose of this study was to compare the effectiveness and complication profile of kyphoplasty and vertebroplasty in a single patient series. STUDY DESIGN/SETTING A clinical series of 36 patients with VCFs treated by vertebral augmentation procedures was retrospectively analyzed for surgical approach, volume of cement injected, cement extravasation (symptomatic and asymptomatic), the occurrence of subsequent adjacent level fracture, and pain relief. PATIENT SAMPLE Thirty-six patients with 46 VCFs underwent either kyphoplasty or vertebroplasty after failing conservative therapy. The mean patient age was not significantly different between the kyphoplasty group (70; range, 46-83) and vertebroplasty group (72; range, 38-90) (p=.438). OUTCOME MEASURES Outcomes were assessed by using self-report measures (a comparative pain rating scale) and physiologic measures (pre- and postoperative radiographs). METHODS Thirty-six patients with VCFs underwent 46 augmentation procedures (17 patients had 20 fractures treated via kyphoplasty, and 19 patients had 26 fractures treated via vertebroplasty). Seventeen patients in this series underwent kyphoplasty using standard techniques involving bone void creation with balloon tamps, followed by cement injection. Nineteen patients underwent a percutaneous vertebroplasty procedure using a novel cannulated, fenestrated bone tap developed to direct cement anteriorly into the vertebral body to avoid backflow of cement onto neural elements. RESULTS Pain improvement was seen in >90% of patients in both groups. Mean cement injection per vertebral body was 4.65 mL and 3.78 mL for the kyphoplasty and vertebroplasty groups, respectively (p=.014). Ninety-five percent of the kyphoplasty procedures were performed bilaterally, whereas only 19% of the vertebroplasty procedures required bilateral augmentation (p<.001). There was no cement extravasation resulting in radiculopathy, or myelopathy in either group. Asymptomatic cement extravasation was seen in 5 of 46 (11%) of the total series (3/20 [15%] and 2/26 [7.7%] of kyphoplasty and vertebroplasty, respectively) (p=.696). Within a 3-month period, there were 5 new adjacent level fractures seen in 3 patients who underwent a kyphoplasty procedure (5/20 [25%]) and none in the vertebroplasty group (p<.05). CONCLUSIONS Vertebroplasty appears to offer a comparable rate of postoperative pain relief as kyphoplasty while using less bone cement more often via a unilateral approach and without the attendant risk of adjacent level fracture.