Computer-Assisted Femoral Augmentation For Osteoporotic Hip Fracture Prevention
Johns Hopkins University
Osteoporosis is the severe reduction in bone mineral density and load bearing capabilities. Individuals with osteoporosis, especially the elderly, are at a higher risk of bone fracture as a result of trauma, with hip fractures being the most prevalent and life threatening. There are currently a number of preventive treatments available; however the side effects, long delays in restoring bone strength or other issues associated with these treatments inhibit their efficacy. A promising new approach to preventing fracture is augmentation of the mechanical properties of the femur by injecting it with acrylic bone cement-femoroplasty. There are risks and limitations associated with femoroplasty, however, that need to be addressed through pre-operative planning and careful execution as well as experimental validation before it finds its way to the operating room. This thesis describes the methods and tools developed for effectively planning and performing femoroplasty. To this end, computational models were developed to simulate various augmentation scenarios and to predict how those affect the mechanical strength of the femur. Those tools were then used to plan femoroplasty for paired cadaveric osteoporotic femur specimens. Experimental tests performed on those specimens showed significant improvements in the load and energy absorbed to fracture the augmented specimens compared to those left intact. We therefore conclude that effective femoroplasty is possible by using computer planning and controlled execution. Although geared towards femoroplasty, these methods and tools can be extended to other types of augmentation surgeries using bone cement including vertebral body augmentation (vertebroplasty) or augmentation of distal radius for prevention of osteoporotic wrist fractures.
osteoporosis, hip fracture, femoroplasty, cement, FEA, optimization, SPH, injection