Locally applied simvastatin promotes fracture healing in ovariectomized rat.

UNLABELLED: Simvastatin solution was injected subcutaneously to the site of fractured tibiae of ovariectomized rats. Afterwards healing quality was evaluated by morphologic, radiographic, biomechanical, histological and histomorphometric methods at 1, 2 and 4 weeks after fracture. Results showed that locally applied simvastatin improved fracture healing.

INTRODUCTION: Many studies have documented an anabolic effect of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, on undisturbed bone. Reports of their effects, however, on fractured skeletal systems have been limited. A study was, therefore, conducted to check the effects of statins on fracture healing.

METHODS: Simvastatin (10 mg/kg/day) was injected subcutaneously to tissue overlying the site of fractured tibiae of ovariectomized rats for a treatment period of 5 days. Vehicle reagent was used as a control. Healing quality was evaluated at 1, 2 and 4 weeks after fracture.

RESULTS: Compared with that in the vehicle group, the callus cross-section area in simvastatin-treated rats was significantly enlarged by 21.3% (p < 0.05) at 1 week and by 21.5% (p < 0.05) at 2 weeks; new woven bone was relatively substantive and arranged more tightly and regularly at 2 and 4 weeks; and maximal load was increased by 57.5% (p < 0.05) at 2 weeks and by 31.4% (p < 0.05) at 4 weeks. Histomorphometrically, simvastatin was associated with a significant (p < 0.05) increase of mineralization width (MLW), mineralization volume (MLV) and mineral apposition rate (MAR).

CONCLUSION: The current study suggests that local application of simvastatin could promote fracture healing in ovariectomized rats.