Early Effect of Simvastatin Gel on Bone Formation of Orthopaedically Expanded Sagittal Suture of Rabbits

Abstract

OBJECTIVES: To evaluate early bone-healing effects of local simvastatin application to orthopaedically expanded sagittal suture of rabbits. MATERIALS AND METHODS: A total of 30 male Rabbits of an average weight of 0 .75-1.0 kg and aged 2-3 months were used in this study. The animals were divided into three groups of ten animals each: simvastatin (group I), active control (group II), and passive control (group III). The sagittal suture was expanded with an expansion spring for one week, after that, the expander was removed and replaced with wire retainer for two weeks .At the time of wire retainer placement: Group I received an injection of 0.5mg simvastatin /0.5ml methylcellulose gel over the suture; group II received 0.5 ml of methylcellulose gel subcutaneously over the expanded suture; group III received no treatment. Half of the animals (five animals in each group) were sacrificed after two weeks of retention, and the sutures were prepared for radiological and histological assessment of regenerated bone. In the other half, the wire retainer was removed after two weeks of retention and the relapsed ratio of the expanded suture was calculated one week later. RESULTS: Local application of simvastatin has been found to have a positive influence on bone regeneration of orthopaedically expanded sagittal suture in comparison to control group. The density of the suture in the simvastatin group was significantly higher than control group. The relapse ratio in simvastatin gel treated group was nearly half that of methyl cellulose carrier gel and control groups, the difference was highly significant. CONCLUSION: 0.5 mg simvastatin greatly promote early bone formation of orthopaedically expanded sagittal suture.