A parametric finite element analysis of the compacted bone–cement interface following balloon kyphoplasty

Abstract

Treating fractures of the spine is a major challenge for the medical community with an estimated 1.4 million fractures per annum worldwide. While a considerable volume of study exists on the biomechanical implications of balloon kyphoplasty, which is used to treat these fractures, the influence of the compacted bone–cement region properties on stress distribution within the vertebral body remains unknown. The following article describes a novel method for modelling this compacted bone–cement region using a geometry-based approach in conjunction with the knowledge of the bone volume fractions for the native and compacted bone regions. Three variables for the compacted region were examined, as follows: (1) compacted thickness, (2) compacted region Young’s modulus and (3) friction coefficient. Results from the model indicate that the properties of the compacted bone–cement region can affect stresses in the cortical bone and cement by up to +28% and −40%, respectively. These findings demonstrate the need for further investigation into the effects of the compacted bone–cement interface using computational and experimental methods on multi-segment models.