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 few 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 proximal femur augmentation and demonstrate its feasibility. Towards this goal, we propose three aims: 1. Surgical planning workstation: based on our prior study we propose to develop a biomechanical planning module for patient-specific optimization of the bone augmentation procedure using preoperative CT scans. We propose to leverage our preliminary results and develop an integrated patient-specific model involving mechanical and hydrodynamic simulation of the bone strength due to the injection of the augmenting material that is suitable for the ubiquitous problem of predicting intraoperative cement injection. The planning workstation will also assess the fracture risk preoperatively as well as provide real-time updates of the predicted cement distribution and stress- state within the bone during the surgery. 2. Integrated surgical execution system: The workstation will provide key capabilities related to image- based registration, intraoperative updates of cement distribution, and robotic tools to control injection. We will integrate software and hardware components; advance the biomechanical planning into a viable intraoperative technology, and tackle segmentation/registration challenges identified in our previous studies. These challenges are described in detail in the research plan. 3. Integrated System Performance: We will investigate the functional performance, reliability, and overall system accuracy of precisely controlled bone augmentation through a series of cadaver studies. The study will also include a series of destructive cadaver tests to verify the system ability to strengthen osteoporotic femora. We will also investigate the safety of the procedure by performing a series of live large animal studies (n =4). The main purpose of large animal studies is demonstrating the safety of the procedure before performing human pilot studies. 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.
| Fotouhi, Javad; Fuerst, Bernhard; Unberath, Mathias et al. (2018) Automatic intraoperative stitching of nonoverlapping cone-beam CT acquisitions. Med Phys 45:2463-2475 |
