Personalized medical devices enable accurate reconstruction of bone defects but can still fail due to a large mismatch in the mechanical properties of device’s material and bones. Device failures are costly, increase pressure on healthcare, and complicate patients’ health. We will develop a computationally efficient framework that can be used in clinical practice to generate patient-specific implants by introducing fine-tuned porosity in clinically approved materials that results in “architected” implants. We will use modern computational methods and patient-specific data to generate such “architected” devices with target mechanical behavior that can optimally match patients’ morphology and minimize the risk of failure and reoperations.
Background & relevance. Patients with bone fractures or cancer resection currently receive off-the-shelf or personalized medical devices (implants or osteosynthesis plates) aimed at replacing or bridging bones. Most such devices are made of solid metal parts (stainless steel, cobalt-chrome alloy, titanium, titanium alloys), which are much stiffer and stronger than bones and have smooth surfaces adversely affecting bone in-growth. The mismatch in mechanical behavior causes bone remodeling and stress shielding that result in the resorption of healthy bones and subsequent screw loosening (e.g., 10-18% for mandibular, 10% for orthopedic and 14-16% for shoulder implants) and device failure (7%-19% for prostheses) requiring reoperation. Reoperation surgeries damage surrounding soft tissue, negatively affect nearby organs and patients’ health, increase infection rate, and increase healthcare workload and costs. Device failures must thus be minimized which can be achieved by improving the compatibility of the device-bone mechanical responses.
As changes in the chemical structure of clinical materials require years of research and clinical trials, it was proposed to control mechanical behavior by modifying the geometric structure of a material (architecture) and preserving its chemical composition. This implies the introduction of complex-shaped pores of milli- or/and micrometer sizes at pre-defined locations that alter mechanical characteristics of the device. This approach is applicable to any material and delivers an architected medium with target mechanical properties. For instance, purposely designed architected porous metals preserve high strength which is not the case for randomly porous (“spongy”) metals.
The expected results for this project include:
Personalized medical devices enable accurate reconstruction of bone defects but can still fail due to a large mismatch in the mechanical properties of device’s material and bones.
