Effects of local application of simvastatin on osteoporotic fracture healing in rats

AIM: Many studies have documented an anabolic effect of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, on undisturbed bone. Reports of their effects on fractured skeleton were limited. A study was therefore conducted to check the effects of statins on fracture healing. METHODS: Simvastatin (10 mg·kg^-1·d^-1) was injected subcutaneously to tissue overlying the site of fractured tibiae of ovariectomized rats for a treatment period of 5 d. Vehicle reagent was used as control. Healing quality was evaluated at 1, 2 and 4 weeks after fracture. RESULTS: Compared with vehicle group, callus cross section area in simvastatin treated rats were 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 in mineralization width (MLW), mineralization volume (MLV) and mineral apposition rate (MAR). CONCLUSION: Current study suggests that local application of simvastatin promotes fracture healing in ovariectomized rats.