3D-Printed Customized Cages for Foot Arthrodesis

Abstract

Featured Application: This systematic review focuses on analyzing the use of 3D-printed cages in foot arthrodesis to address complex bone defects, failed prior fusions, severe bone loss, or deformities. The application of customized Ti-6Al-4V open-structure, porous implants, manufactured through additive manufacturing processes such as electron beam melting (EBM), selective laser melting (SLM), or direct metal laser sintering (DMLS), is demonstrated to ensure osseointegration and provide a proper anatomical fit and mechanical stability. In recent years, the application of 3D-printed implant cages or trusses for foot arthrodesis has emerged as a personalized approach to address complex bone defects and deformities. Twenty studies involving different regions of the foot, such as the ankle and subtalar joints, were reviewed to document the 3D-printed custom solutions. The design of these implants is also discussed, including custom titanium trusses and lattice structures, which can promote osseointegration and fit the bone geometries. From a mechanical perspective, these implants proved to be stable and compatible with natural bone, aiming to reduce stress shielding while offering the mechanical strength needed for optimal outcomes. This systematic survey also addresses the additive manufacturing processes involved, namely EBM, SLM, or DMLS. Clinical cases were focused on patients with large bone loss, failed prior fusions, and deformity corrections, with the follow-up results showing high rates of fusion and functional improvement. Of the analyzed studies, three provide level III evidence, while the rest provide level IV or V, consisting of case series or reports. Since 2015, 148 patients have been reported to receive such implants. This review addresses the question, “how effective are 3D-printed titanium cage implants in foot arthrodesis in addressing large bone defects and deformities?” It is the first review to gather data on the use of such customized implants in foot arthrodesis, providing critical insights to enhance their application, including amputation avoidance. This study highlights the advantages of personalized 3D-printed implants in achieving a better anatomical fit, improving clinical outcomes, and ensuring faster recovery times, while also addressing considerations such as the cost and the need for long-term clinical data.