There is a wealth of research on the extent to which bone loss may impair strength and increase the risk of fracture. The rate of mortality after hip fracture in elderly patients with osteoporosis is reported to be as high as 30%. It is suggested that augmentation of the femur is an effective countermeasure to reduce the risk of fracture in highly osteoporotic hips. This technique would be especially valuable for those patients at high risk of falls and the highest risk of mortality and morbidity if they were to sustain a fall. The fw clinical case studies that have been performed on augmentation of the femur suggest that a successful outcome requires detailed planning, biomechanical analysis, and precise control of the augmentation procedure to avoid generation of areas of high stress due to augmentation. Our long term goal is to develop a technology that enables the surgeon to precisely determine the extent of osteoporosis and fracture risk level, obtain an optimized surgical plan based on computerized mechanical analysis, perform a rapid and minimally invasive hip augmentation with intraoperative biomechanical feedback, and finally verify the outcome in one patient visit. In this project, we will develop a surgical test bed for planning proximal femur augmentation and demonstrate its feasibility. Towards this goal, we propose two aims: 1. Optimal planning of the femoroplasty: We propose to develop a novel framework involving a computational diffusion model applied to patient-specific CT scans of the osteoporotic femora. The model will be suitable for the ubiquitous problem of predicting an optimal pattern and strategy for cement injection using input from both patient-specific CT and another computational model for assessment and reduction of the fracture risk. 2. Validation of the preoperative planning strategy: We will perform a series of controlled nondestructive cadaver tests to verify the accuracy of our model in predicting the diffusion geometry of the augmentation material. We will also perform a series of destructive cadaver tests on osteoporotic femora to verify the abiliy of the planning framework to strengthen the bone with a relatively low injection volume of the augmentation material. The technology developed in this project may lead to a highly needed alternative treatment that may be pivotal for patients at the risk of bone fracture due to osteoporosis as well as demonstrating the importance of incorporating biomechanics-based planning in end-to-end surgical treatment.
|Basafa, Ehsan; Armand, Mehran (2014) Subject-specific planning of femoroplasty: a combined evolutionary optimization and particle diffusion model approach. J Biomech 47:2237-43|