miRNA expression data from callus in standard fracture healing models and from fibrous tissues in nonunion models in rats on post-fracture day 14

Profiling of miRNA expressions comparing standard fracture healing models with nonunion models in rats 12w, male, Sprague–Dawley rats were used in this study. Animals were randomized to receive either a surgical treatment that has been shown to produce a nonunion or to a standard stabilized closed femoral shaft fracture that is known to successfully heal. The details of these procedures have been previously described. Briefly, to produce standard healing models, a 1.2-mm diameter K-wire was inserted retrograde into the right femoral intramedullary canal and a closed transverse femoral shaft fracture was produced using a three-point bending apparatus with a drop weight . To produce the nonunion, the fractured site was additionally exposed, and the periosteum was cauterized circumferentially for a distance of 2 mm on each side of the fracture . Five animals from each group were euthanized on post-fracture day 14 for microarray analysis.