The suitability of Synbone® as a tissue analogue in ballistic impacts

Knowledge of material behaviour under impact is of key importance to understand ballistic impact events on tissue. Bone- with it’s complex underlying microstructure- is no exception; the microstructural network in bone is not only crucial to its integrity, but also provides a pathway for energy dispersion upon impact [1]. Synbone®, a Swiss-made polyurethane bone simulant, has been considered as a potential bone analogue, particularly for cranial structures [2, 3, 4]. This study focused on long bone models and cylinders available from Synbone®, with the aim of determining their efficacy for use in ballistic testing and recreation. Comparisons were made between porcine bone and multiple Synbone® models regarding projectile energy loss and damaged surface area using high-speed video and high-resolution photography. CT and reverse ballistics techniques were also used as diagnostic tools. A significant correlation was made between real bone and Synbone®’s ballistic cylinders in all aspects of this study; however, it was observed that osteoporotic cylinders and anatomical models differ significantly in their reaction to impact. Consequently, the use of Synbone® as a ballistic target simulant- particularly when legal or practical accuracy is essential- will need to be treated carefully, giving due attention to these limitations.