Performance of additively manufactured Ti6Al4V ELI finger joints: biomechanical testing and evaluation for arthritis management

Approximately 24 out of every 100 adults in the United States, or 58.5 million people, have arthritis, which refers to a condition that causes pain and inflammation in a joint according to US National Center for Chronic Disease Prevention and Health Promotion. Osteoarthritis is the most common type of arthritis, and it may damage almost any joint but mainly occur in hands, hips and knees. While there are several joint replacement options for hips and knees, there are only limited options for finger joints. In this paper, we report on several aspects of testing of novel finger joints: testing apparatus design, cadaveric performance test and material testing results of titanium joints using 3D-printed Ti6Al4V extra low interstitial (ELI). Soft cadaveric hands with finger joints were surgically replaced by additively manufactured titanium joints following the exact same anatomy of the cadavers. These small joints were engineered to mimic the biological and natural movements of fingers. The apparatus, methodology and results of biomechanical tests were deployed to evaluate and validate the joints particularly those of titanium joints manufactured via laser powder bed fusion methods (PBF-L/M).