Aims and Scopes:

Large bone defects resulting from trauma, tumor resection, infection, and congenital anomalies remain a major clinical challenge. Conventional autograft and allograft approaches are constrained by donor-site morbidity, limited availability, poor adaptability to irregular defect geometries, and inherent complication risks (e.g., immune rejection, infection). 3D printing and bioprinting technologies overcome these limitations by enabling patient-specific, structure-function-matched bone repair, allowing precise customization of scaffold/implant geometry, porosity, mechanical properties, and spatiotemporal release of bioactive factors. Recent advances in printable biomaterials (calcium phosphates, bioactive glasses, polymer-ceramic composites, biodegradable metals), multi-material fabrication, and cell/factor-encapsulated bioinks accelerate development of constructs that boost osteogenesis, vascularization, and osteoimmunomodulation. In parallel, optimized image-to-print workflows, computational design, in situ printing, and scalable manufacturing improve clinical translatability.

This Special Issue showcases cutting-edge research and reviews covering materials innovation, biological mechanisms, preclinical validation, and early clinical evidence, with emphasis on reproducibility, standardization, and translational pathways for real-world 3D-printed bone repair solutions.