| dc.description.abstract | The Food and Drug Administration (FDA) defines non-union as a fracture that has not fully healed within 9 months and has not shown further signs of healing after 3 months (1). There are three categories in which diaphyseal fractures are differentiated: Simple fractures consisting of spiral fractures, oblique fractures, and transverse fractures, wedge fractures consisting of spiral wedge, fragmented, and bending wedge, and complex fractures consisting of spiral, irregular, and segmental fractures(2). Following femoral non-union diagnosis, several options are presented to the surgeon and the patient. The five most common operative treatments for femoral non-union in order of most common, to least common are: dynamization, reamed nailing after plate, exchange reamed nailing, augmentative plate fixation, and plate fixation. The current non-union treatments presented all aim to provide a fix to non-union but fail to address the preventative issue of non-union itself. It would be advantageous to develop a surgical implant that will decrease the non-union rate while keeping surgical procedures the same for surgeons. There are several therapeutic interventions once non-union is determined all with the common downside associated with their use of not addressing non-union before a patient suffers from non-union. These products are prescribed after a patient is diagnosed with a non-union or malunion where the most effective treatment to end non-union is to treat the source of healing issues. A product that provides such a therapy must be easily implanted by surgeons, ideally having no difference in surgical procedure as that of existing products. The product must not only decrease non-union rates but should decrease the time to fusion of those who are not in the difficult-to-fuse category. The goal in development of a new IM nail is to decrease the rate of non-union while providing the same structural integrity as existing products. The designed IM nail shows that it will hold the necessary loads associated with a femoral fracture fixation device while also providing deformation to the lead zirconate titanate (PZT) insert allowing for power production to increase bone growth. In the development of a piezoelectric IM nail, twelve specimen were created using piezoelectric rings. Three different specimen type (compliant layer thicknesses) were created with compliant layer (CL) thicknesses of 0.0 mm (0T), 0.7 mm (1T), and 1.4 mm (2T). Each specimen was tested in different loads of 100 N, 500 N, and 1000 N with frequencies of 1 Hz, 2 Hz, 3 Hz, 5 Hz. These loads and frequencies were to act as physiological loads as seen by orthopedic implants to characterize the power production capabilities of piezoelectric rings. This study showed that by interdigitating CLs power production as well as fracture toughness increases from 0T to 1T, from 0T to 2T and from 1T to 2T. The results show a promising development in the use pf PZT as a low frequency power generator for bone healing applications. | |
