[Effect of intramedullary reaming and nailing on the production of growth factors in the femur fracture callus in rats].

INTRODUCTION Many studies have been conducted to determine the different effects that reaming or intramedullary nailing have on fracture healing, but there is no evidence in the literature of the effect of intramedullary reaming on osteogenesis. We performed a prospective study to analyse the effect of intramedullary reaming and nailing on the production of growth factors during the process of fracture healing in the femur of rats. MATERIAL AND METHODS A transverse mid-shaft non-comminuted femur fracture was produced in 64 rats; 34 rats did not receive any treatment, and a standardized surgical procedure was performed on 30 rats, by exposing the left knee, reaming the medullary canal from distal to proximal, and then fixing the fracture with a steel pin. The rats were sacrificed at the 24th hour, 4th, 7th and 15th days after the fracture. The amount of growth factors that appeared in the callus fracture was measured using histopathology studies. The primary categorical variables analysed were PDGFA, TGF2 and TGFβ-R2. These variables were analysed in each group at the different sacrifice times. RESULTS The results of the primary variables of the study, stratified by the time until sacrifice, showed no statistically significant differences. DISCUSSION Even if the presence of an intramedullary wire facilitates the fracture repair and the stabilising the bridge of bone between both edges of the fracture site, no evidence was found that reaming changes the expression of the growth factors studied (PDGFA, TGFβ-R2 and TGFβ2) during the callus formation in rats.