The biomechanical effect of vertebroplasty on the adjacent vertebral body: a finite element study.

The increased use of vertebroplasty for the treatment of osteoporotic vertebral compression fractures has led to concerns that the technique may increase the risk of fracture in the adjacent vertebrae. The aim of this study was to simulate the biomechanical effects of vertebroplasty using an osteoporotic two-vertebrae finite element model. Following a simulated compression fracture, the model was augmented with one of three volumes of PMMA-based cement or left untreated. Upon reloading, an increase in segment stiffness was found with increasing volumes of cement. However, in all the treated models there was an increase in endplate deflection into the adjacent vertebra causing plastic failure of the surrounding trabecular bone. More damage was caused in the adjacent vertebra of the treated models than in the untreated model. The model results suggest that clinicians should be wary of using standard vertebroplasty cements to treat compression fractures in patients with highly osteoporotic bone.