New Levels of Vertebral Compression Fractures after Percutaneous Kyphoplasty: Retrospective Analysis of Styles and Risk Factors

Background: The causes of subsequent vertebral fractures after kyphoplasty are debated. It is reported that most new vertebral fractures after kyphoplasty develop in adjacent vertebrae. Objectives: We explored whether kyphoplasty increases the incidence of adjacent vertebral fractures and identified risk factors for new vertebral compression fractures (VCFs) after kyphoplasty. Study Design: Retrospective study. Setting: Inpatient population of a single center. Methods: We studied 356 patients treated with kyphoplasty from January 2008 to March 2012. Among those patients, there were 35 new VCFs after kyphoplasty. Subsequently, these patients were divided into 2 groups: an “adjacent fracture” group and a “nonadjacent fracture” group. In addition, all patients treated with kyphoplasty were further assigned to either a “new fracture” group or a “no fracture” group. Results: The occurrence of new VCFs in the “nonadjacent fracture” group was significantly higher than that in the “adjacent fracture” group. The average bone mineral density (BMD) of the spine was -3.95 in the “new fracture” group and -2.86 in the “no fracture” group. The risk of new vertebral fracture increased as the bone mineral density decreased (P < 0.05). The morbidity of women was significantly higher in the “new fracture” group (94.29%) than in the “no fracture” group (77.88%) (P = 0.025). Limitations: Retrospective study at a single center. Conclusion: New VCFs after kyphoplasty occurred most often in nonadjacent vertebrae. VCFs after kyphoplasty were common in patients with low bone mineral density and in women, suggesting that osteoporosis is an underlying mechanism. Institutional Review: This study was approved by the institutional review board. Key words: Percutaneous kyphoplasty, vertebral compression fractures, bone mineral density, polymethylmethacrylate, adjacent vertebral fracture