Patients usually recover from bone fractures with the right treatment, but sometimes the bone fails to heal because new tissue does not form and connect the broken pieces properly. Delayed union refers to cases where the bone takes longer than usual to heal, and nonunion refers to cases where the bone does not heal. In approximately 5 to 10 percent of cases of a fractured bone, delayed union or nonunion occurs. These conditions are associated with long-term pain and discomfort, and though can be addressed through surgical treatments, these interventions do not always lead to long-term healing.
In recent years, researchers have begun exploring the potential for mesenchymal stem cells to help address these important challenges of delayed union and nonunion. A review of the potential for these stem cells to help in these cases where fractures do not properly heal was recently published in the Journal of Biomedical Materials Research.
Mesenchymal stem cells are helpful in bone healing because they differentiate well and can differentiate into different cell lineages that are all important for bone formation, growth, and maintenance. These cell types include chondrocytes, osteoblasts, myoblasts, and adipocytes.
According to the authors of the review, mesenchymal stem cells can be used in conjunction with extracellular matrix scaffolds and biological adjuvants that promote growth, differentiation, and blood vessel formation, to help in the bone healing process when the delayed union or nonunion occurs. Future research will help to determine the best ways that mesenchymal stem cells can be used in combination with bioengineering strategies to help patients whose bone fractures do not heal or do not heal properly.