Balloon Kyphoplasty and Subsequent Fracture Risk

Why does one VCF apparently lead to another? Are subsequent VCFs more likely to be adjacent or remote? How does vertebral body augmentation affect the rate of subsequent VCFs? To address these questions, this white paper presents the risk factors associated with initial VCFs and relates those risk factors to the incidence of subsequent VCFs. The authors also review spinal anatomy and biomechanics and present data on fractures post-vertebral body augmentation.

Conclusions
Prior fracture is the most prominent risk factor for new VCF due to the presence of underlying risk factors for osteoporosis. (1) Adjacent VCFs are especially common and may be explained by increased local forces resulting from kyphosis at the index fracture (see Figures 1 and 2). Finally, biomechanical studies provide little support for a concern of increased fractures with vertebral body (VB) augmentation, since: 1) augmentation of the VB with bone cement does not increase stiffness of the VB beyond the prefracture state, and 2) the intervertebral discs, not the VBs, ultimately govern how load stress is absorbed by the spine.

VCFs and the questions surrounding subsequent VCFs remain an important topic. VB augmentation with balloon kyphoplasty may improve spine biomechanics by improving the overall sagittal alignment of the VB, resulting in decreased kyphosis and reduced local forces that promote subsequent adjacent fractures. The authors conclude that further controlled studies comparing balloon kyphoplasty to non-surgical management for VCFs will answer more definitely the subsequent fracture question.

References
1. Lindsay R, Pack S, Li Z. Longitudinal progression of fracture prevalence through a population of postmenopausal women with osteoporosis. Osteoporos Int. 2005;16:306-312.

2. Belkoff S, Maroney M, Fenton D, Mathis J. An in vitro biomechanical evaluation of bone cements used in percutaneous vertebroplasty. Bone 1999; 25:23S-26S.

3. Tomita S, Molloy S, Jasper LE, Abe M, Belkoff SM. Biomechanical comparison of kyphoplasty with different bone cements. Spine 2004;29:1203-1207.

Fracture Line
Volume 2, Number 2, Winter 2005

The Fracture Line is published by Kyphon Inc. to educate and inform our customers about the latest advances in vertebral compression fracture management.

To receive a copy of this white paper, please submit your request to info@kyphon.com.

As with any surgery, there are potential risks. Although balloon kyphoplasty is designed to minimize these risks as much as possible, there is a chance that complications could occur. Serious adverse events can occur including: myocardial infarction (heart attack), cerebrovascular accident (stroke), pulmonary embolism (cement leakage that migrates to the lungs), cardiac arrest (heart stops beating), paralysis or muscle weakness, death. Patients should consult with their doctor for a full discussion of risks.