Decreased pool of mesenchymal stem cells is associated with altered chemokines serum levels in atrophic nonunion fractures

► The pool of bone marrow-derived mesenchymal cells is decreased in nonunions. ► The osteogenic potential of mesenchymal cells is preserved in nonunions. ► Serum levels of proliferative growth factors and chemokines are altered in nonunions. ► The pool of endothelial progenitor cells is preserved in atrophic nonunions. ► Serum levels of angiogenic growth factors are preserved in atrophic nonunions.