The sole use of stem cells in treating fracture nonunion: a scoping review.

Objective of this study: This scoping-review aims to highlight the current modalities of sole use of stem cells in treating fracture nonunion updating a previous systematic review from 2013. We report solitary stem cell stimulation in literature in vivo studies to obtain current knowledge in understanding the crucial role of stem cells in enhancing fracture nonunion healing.

Materials and methods: This scoping review was conducted by systematical search in PubMed, Medline and clinicaltrials.gov with a timeframe from October 2012 to September 2024. Two authors independently screened all articles, and when included, the following information was extracted: type of nonunion, localization, type of stem cells, administered dose of stem cells, surgical information, type of scaffold, control group, evaluation method, time of evaluation post intervention, and adverse events.

Results: Of 4710 articles screened, 27 articles met the criteria for inclusion. In the reviewed articles, 2 out of 5 human studies, and 8 out of 12 animal studies with a control group reported a statistically significant effect of stem cells on bone healing when used in the treatment of fracture nonunion. Comparison of the studies was difficult due to heterogeneity. The administration of mesenchymal stem cells regarding adverse events was investigated in eight human studies.

Conclusion: Based on our reporting, the articles suggest that the perspectives of the sole use of mesenchymal stem cells in the management of fracture nonunion might be promising but remain inconclusive. Future research should be inspired by existing literature and focus on the development of well-standardized methodologies and results published.