Polymer Characterization for Soft-Tissue Fixation Devices
presentationposted on 2014-09-12, 00:00 authored by Jonathan Schlotthauer
The overall goal of this study was to fabricate and mechanically characterize a high-strength porous polymer scaffold for use as an orthopedic soft-tissue fixation device. Orthopedic soft-tissue fixation devices are used in a wide variety of medical procedures to reattach a torn tendon or ligament to a bone (over 2 million procedures performed in 2011). Currently used devices are either incompatible with medically relevant imaging techniques (most metals) or lack the mechanical strength for soft-tissue fixation (most polymers). Our fundamental hypothesis was that the exceptional strength, stiffness, and toughness of newly developed self-reinforced polyphenylene (SRP) allows for a porous structure appropriate for osteointegration that can match the stiffness of bone, while maintaining suitable mechanical properties for soft-tissue fixation. Powder-press sintering followed by particle leaching was used to fabricate porous SRP specimens containing an average pore size of approximately 400 μm, with systematically varied pore volume fraction from 55-85% vol. Mechanical testing and scanning electron microscopy was used to measure and visualize deformation behavior, and results were critically evaluated relative to existing theory used to describe foams. Results showed that porous SRP matched the stiffness of trabecular bone at pore volume fractions ranging between 75-85% vol.