3D Bioprinting for Custom Bone Grafts in Orthopaedic Trauma: Current Advances and Clinical Translation.

Traumatic bone loss in orthopaedic trauma presents significant clinical challenges, particularly arising from high-energy injuries, open fractures with segmental defects, and blast trauma, where bone loss exceeds the critical size for spontaneous healing. Traditional management strategies, including autografts, allografts, and the Masquelet-induced membrane technique, are associated with limitations such as donor site morbidity, prolonged treatment duration, multiple surgical procedures, and suboptimal outcomes. Three-dimensional (3D) bioprinting technology has emerged as a promising solution for fabricating patient-specific bone grafts tailored to individual defect geometry and mechanical requirements.  This narrative review examines current advances in 3D bioprinting specifically for orthopaedic trauma applications, focusing on technologies relevant to long bone reconstruction, load-bearing requirements, and complex fracture management. We analyze various bioprinting modalities, including extrusion-based and stereolithography techniques, alongside biomaterial developments in bioceramics, biodegradable polymers, and mechanically competent composite scaffolds. Clinical applications in femoral and tibial segmental defects, periarticular fractures, and combat-related extremity injuries are reviewed, with emphasis on preclinical large animal models and early clinical experiences. Critical challenges specific to orthopaedic trauma, including mechanical loading demands, infection risk in contaminated wounds, and integration with existing fixation systems, are discussed.  This review examines emerging innovations, such as in situ bioprinting for intraoperative graft fabrication and personalized approaches incorporating patient-derived cells and growth factors. As bioprinting technology continues to mature, integration into orthopaedic trauma protocols promises to reduce treatment complexity, accelerate healing, and improve functional outcomes for patients with devastating skeletal injuries requiring advanced reconstructive solutions.