Clinical bottom line
Emerging biomaterials for bone regeneration in orthopedic surgery offer promising advances in enhancing bone healing, structural support, and integration. Innovations spanning zero- to four-dimensional biomaterials—including bioactive scaffolds, hydroxyapatite hybrids, and stem cell–modulating constructs—show potential to improve outcomes in complex bone defects and nonunions. However, translation from bench to bedside remains limited by variability in preclinical models, manufacturing challenges, and incomplete understanding of long-term biocompatibility and remodeling dynamics. Careful evaluation of emerging materials alongside established grafting techniques is warranted to optimize patient-specific strategies (Fang et al., 2022; Wang et al., 2024).
What the evidence shows
Fang et al. (2022) provide a comprehensive overview of biomaterials classified by dimensionality, from zero-dimensional nanoparticles to four-dimensional smart materials capable of dynamic responses. These materials can modulate cellular behavior, promote osteogenesis, and adapt to biomechanical environments, offering tailored regenerative potential.
Wang et al. (2024) report engineering of large-scale self-mineralizing bone organoids using bone matrix-inspired hydroxyapatite hybrid bioinks, demonstrating enhanced mineral deposition and structural fidelity in vitro, which may translate into improved graft integration.
Pajarinen et al. (2019) highlight the critical role of mesenchymal stem cell–macrophage crosstalk in bone healing, suggesting biomaterials that modulate immune responses could optimize regenerative outcomes.
Merolli et al. (2019) review current bone repair biomaterials in orthopedic surgery, emphasizing the importance of biocompatibility, osteoconductivity, and mechanical properties, while noting limitations of existing synthetic and natural graft substitutes.
Sezgin et al. (2024) discuss biomaterial carriers for managing bone disorders, underscoring the need for multifunctional platforms that deliver cells, growth factors, and drugs to enhance regeneration.
Caveats and uncertainty
Most evidence derives from preclinical studies with limited clinical trial data, restricting direct applicability.
Heterogeneity in biomaterial composition, fabrication methods, and evaluation metrics complicates cross-study comparisons.
Long-term safety, degradation kinetics, and host immune responses remain incompletely characterized.
Manufacturing scalability and regulatory pathways for complex biomaterials pose challenges.
Patient-specific factors such as comorbidities and defect size influence biomaterial performance but are underexplored.
How this may change practice
Orthopedic surgeons may increasingly incorporate advanced biomaterials as adjuncts or alternatives to autografts/allografts, particularly in challenging reconstructions.
Multidisciplinary collaboration with bioengineers and material scientists will be critical to tailor biomaterial selection and optimize outcomes.
Clinicians should remain informed about emerging evidence and participate in clinical trials evaluating novel biomaterials.
Personalized regenerative strategies integrating biomaterials with cellular and molecular therapies may become standard in complex bone repair.
Institutional protocols may evolve to include biomaterial-based options as evidence matures.