Factors Affecting Kyphotic Angle Reduction in Osteoporotic Vertebral Compression Fractures with Kyphoplasty

This article describes the independent factors that affect kyphotic angle reduction in the treatment of osteoporotic vertebral compression fractures with kyphoplasty. Between January 2008 and September 2011, one hundred twenty-six patients with a single-level osteoporotic compression fracture who underwent kyphoplasty were evaluated for a minimum of 1 year postoperatively. Nine independent variables related to patient characteristics (age, sex, bone mineral density [BMD], and body mass index), fracture characteristics (fracture level, fracture age, and preoperative kyphotic angle), and surgical variables (total injected cement volume and cement leakage) were assessed. Kyphotic angle reduction was the dependent variable. Univariate and multivariate linear regression analyses were used to determine the factors associated with kyphotic angle reduction. Significant improvements occurred in mean anterior vertebral height variation, middle vertebral height variation, kyphotic angle, and visual analog scale and Oswestry Disability Index scores immediate postoperatively and at final follow-up compared with the preoperative values. Univariate analyses indicated correlations between kyphotic angle reduction with BMD, fracture age, preoperative kyphotic angle, and cement volume. The final multiple linear regression model resulted in a formula that accounted for 23.3% of the variability in kyphotic angle reduction: preoperative kyphotic angle (b=0.260; P=.002), BMD (b=-0.249; P=.004), and fracture age (b=-0.226; P=.009). Kyphoplasty is a safe and effective treatment for osteoporotic compression fractures.