Students:
- Gabriella Becker,
- Allyn Calvis,
- Lauren Hazlett (Project Leader),
- Mary Verzi
Advisor: M. Paliwal
Approximately 55,5000 proximal humeral fractures require surgical intervention for fixation annually. The current standard for internal humeral fracture fixation involves implantation of metallic devices, which rigidly fixate the bone to prevent dislocation of bone fragments. However, rigid fixation can cause significant stress shielding of bone. Fixation can also be accomplished through biological fixation, which significantly reduces stress shielding by implanting more flexible devices, but leads to increased incidences of delayed healing and nonunion of fracture fragments. The purpose of our design is to create a device that implements two bioabsorbable polymers that degrade at different rates. The device will provide rigid fixation for the bone to prevent misalignment during the initial fracture healing phase until the first polymer degrades, followed by a period of biological fixation while the second polymer allows for functional healing and reduces stress shielding over time. The bioabsorbable aspect of the design allows for the device to remain in situ, thus eliminating the need for removal surgery and the risk for surgical site infection. The success of the design will be evaluated based upon the ability of the plate to prevent dislocation of the bone at all phases of healing, while reducing stress shielding by providing a secondary geometry and loading capability for the device.