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.

Strong similarities in the creep and damage behaviour of a synthetic bone model compared to human trabecular bone under compressive cyclic loading

“…These models have been further utilised to study the micromechanics of the bone cement interface, which is an important feature for augmentation outcomes (Purcell et al, 2014(Purcell et al, , 2013Zhao et al, 2012). Many of these studies utilise an aluminium based open cell structure, which have been found to exhibit favourable properties for the study of cement injection micromechanics in terms of damage evolution and distribution (Guillén et al, 2011).…”

Biomechanical Comparison of Vertbroplasty, Kyphoplasty, Vertebrae Stent for Osteoporotic Vertebral Compression Fractures -A Finite Element Analysis

“…In this study, 50% volume in the cancellous bone space of T12 vertebral body was excavated in the shape of sphere; then bone cement elements conforming to the spherical shape were created and put into the cavity to simulate bone cement injection, and bone cement with 40% volume of the injured vertebra was used to augment the T12 body, which is similar to that proposed by Purcell et al. 27…”

Computational modelling of bone augmentation in the spine

“…In this work, however, the damaged elements are defined in a previously performed mechanical test. Yet another aspect of bone augmentation is considered in the presented model of a whole augmented vertebra by Purcell et al [43] . Some augmentation procedures push the trabecular structures out of the augmentation volume leading to a region of more compact trabecular bone at the edge.…”

“…The augmentation volume is often created artificially in order to test different augmentation shapes and levels of augmentation [38] , [39] , [43] , [46] , [47] , [48] , [49] as shown in Figure 5 . Purcell et al [43] used a horizontally oriented barrel model to represent the augmentation volume. Similarly, Polikeit et al [38] modelled the cement as vertically oriented barrels to simulate bi- and unipedicular augmentation.…”