Foot and ankle biomaterials: a comprehensive review of current applications, challenges, and future directions

Metallic biomaterials enable successful reconstruction and fixation of skeletal tissues by supporting repair, load-bearing function, and anatomical alignment in foot and ankle surgery. However, the unique anatomic and biomechanical demands of this region, combined with challenging pathologies such as flatfoot and Charcot neuroarthropathy, present distinct challenges, with effective intervention requiring targeted biomaterial solutions and precise indications. Furthermore, metallic biomaterials currently represent the most predominant and clinically validated fixation systems in foot and ankle surgical reconstructions, while also generating the largest body of outcome-based evidence. This review summarizes and discusses their contemporary applications, outcomes, limitations, unmeet needs, and future directions based on clinical literature between 2020 and 2024. Emerging innovations, including 3D-printed titanium implants for patient-specific reconstructions, surface-engineered alloys designed to improve osseointegration, with infection mitigation properties for at risk patient populations, and the exploration of bioresorbable/biointegrative magnesium, as well as non-metallic alternative materials (e.g. polymerics) were examined. Persistent unmet needs identified in the literature include hardware challenges in osteoporotic bone and neuropathic patients, ion leeching, cyclic fatigue, economic burden, imaging artifact interference, and lack of long-term data or clinical trials on innovative implant designs and manufacturing approaches. Lastly, scanning electron microscopy (SEM) imaging of titanium, nitinol, and stainless steel is provided to offer an analysis on biomaterial-specific microstructural features, such as surface roughness and porosity, that play a role in influencing tissue integration, corrosion behavior, and mechanical performance in reconstructive surgeries. The Translational Potential of this Article: This review provides clinically actionable guidance for selecting metallic biomaterials tailored to the biomechanical and pathological demands of foot and ankle surgery, supporting evidence-based decisions of selection of hardwares, improved fixation strategies, and reduced complication rates. It also adds recent insights to inform the development and optimization of next-generation devices based on patient- and site-specific requirements, such as 3D-printed constructs and surface-engineered implants, designed to enhance fusion, reconstruction, and limb salvage outcomes.