Targeted Bone Augmentation Strategies: Imaging and Computational Models

Bone is a remarkable material, capable of withstanding high mechanical loads while remaining lightweight and self-regenerating throughout most of our lifespan. However, with age and hormonal changes, bones weakened by osteoporosis become prone to fractures, posing significant clinical challenges. Managing patients at immediate fracture risk remains difficult, as current systemic anti-osteoporotic treatments act slowly and locally. Local bone augmentation presents an alternative strategy to address these challenges. Over the past decades, techniques such as bone cements and metal implants have been explored to locally reinforce osteoporotic bone. In the spine, percutaneous vertebroplasty - a technique introduced in 1987 - involves injecting polymethylmethacrylate (PMMA)-based cement into vertebral bodies. While effective, this procedure is limited by risks of cement leakage, necessitating precise control of injection volume and distribution. Similarly, the proximal femur has been a target for reinforcement using polymer-PMMA implants, calcium phosphate cements, or bioactive hydrogels. However, in both cases, determining the optimal regions for augmentation and the feasibility of material injection remains a significant challenge. To address these issues, we adopted a multidisciplinary approach integrating advanced imaging, mechanical testing, and computational modeling. High-resolution 4D computed tomography (4D CT) was used to capture experimental data on cement flow in real bone structures. This data was then used in finite element models to evaluate mechanical strength improvements under both static loading and advanced side-fall simulations, reflecting real-world fracture scenarios. Furthermore, we used lattice Boltzmann simulations to predict cement flow dynamics at high resolution, allowing us to map precise material distributions based on individual bone microarchitecture. While this approach demonstrates significant potential to optimize local bone reinforcement techniques, it also highlights the current gap between these advanced imaging and computational tools and their feasibility for clinical application. The future of this technology is promising, yet the need for accessible and efficient clinical solutions remains a critical hurdle to overcome.