1The biomechanics of vertebroplasty: a review

Abstract: Percutaneous vertebroplasty and kyphoplasty are being used extensively in the United States for the treatment of osteoporotic vertebral compression fractures. Although short-term clinical outcomes appear favourable, long-term data are not yet available and it is becoming increasingly important to understand how the underlying biomechanics of the spine are altered by the procedure. In vitro experimental studies have investigated the eect of cement augmentation on individual ver-tebra and short spinal segments. For individual vertebra, vertebroplasty appears to increase or return strength to the prefracture level, whereas the stiness is not always restored. However for multiple-vertebra segments, the strength of the unit as a whole appears to decrease, with failure occurring in the non-augmented vertebrae. Both nite element (FE) and experimental studies have shown that the volume of cement injected aects the restoration of strength and stiness. The type of cement appears to have less of an eect. Although biomechanical studies of the vertebroplasty process have indicated that the procedure has the potential to restore vertebral strength and stiness, further work is necessary to understand fully the eects of the augmentation process on the surrounding structures if the treatment is to be fully optimized. This paper is a review of the biomechanical data available on vertebroplasty