In situ bioprinting for bone defect reconstruction: Current state and future prospects in traumatology and orthopaedics

Bioprinting is one of the most rapidly evolving technologies in regenerative medicine, integrating cell biology, engineering, chemistry and materials science to create viable tissue constructs, including directly at the site of injury, i.e. intraoperatively or in situ. Of particular interest is bioprinting for bone defect regeneration, given the high prevalence of traumatic injuries and the limited effectiveness of standard autograft and allograft transplantation methods. The aim of this review is to analyze the current state of in situ bioprinting in bone defect reconstruction, characterize existing technical solutions and bioinks, and identify the key barriers to clinical translation while assessing possible strategies to overcome them. The review examines the fundamental principles of intraoperative delivery of bioinks into the wound bed, presents new data on methods and devices for bioprinting in bone defect repair, and provides examples of successful application of the technology in experimental settings. Current trends in technological advancement and points of convergence between bioprinting and orthopedic treatment modalities are highlighted. The prospects for in situ bioprinting in traumatology and orthopedics are outlined, based on the development of robotic systems for use in the operative field, the improvement of organ-building blocks, and their transplantation with consideration of the stages and specific features of the injury. It is shown that in situ bioprinting is not an alternative to classical orthopedic techniques but is seamlessly integrated into them as a regenerative-enhancing component, thereby improving the efficacy of large defect repair through stimulation of the patient’s own osteogenic potential.