局部单次注射辛伐他汀增强大鼠疏松骨骼内固定强度的实验研究

Local single administration of simvastatin exerts positive effect on the early titanium screws fixation in an osteoporosis rat model

目的探讨疏松骨骼局部注射辛伐他汀对内固定强度的影响及其作用机制。方法取3月龄雌性SD大鼠24只，切除双侧卵巢制备大鼠骨质疏松模型。3个月后将动物随机分为三组。右侧股骨髁植入钛合金螺钉后于髓腔内分别注射5mg、10mg辛伐他汀或空白PBS缓冲液。术后1个月行骨密度测定、螺钉周围骨微结构定量分析，钡4定螺钉最大载荷，通过免疫组织化学染色观察BMP-2的表达。结果辛伐他汀5mg组、10mg组骨密度分别为（201±23．3）、（207．9±23．5）mg／cm^2，与空白PBS缓冲液组（170．8±13．8）mg／cm^2。比较差异有统计学意义；螺钉骨整合率分别为51．4％±3．0％、52．6％±4．1％，较空白PBS缓冲液组（273％±4．9％）增加，

Objective To evaluate the effect of locally applied single dose of simvastatin in the fe- murs of osteoporotic rats on the initial stability of titanium screws inserted into distal femurs, and to explore the mechanism related to the effect. Methods Twenty-four female 3-month-old SD rats were ovariectomized （OVX） to induce osteoporosis. 12 weeks later, the animals were randomly divided into three groups with 8 in each. After the titanium alloy screw was implanted into the right femoral condyle, simvastatin 5 rag, 10 mg and a blank PBS buffer were injected into the medullary cavity. Four weeks after the implantation combined with simvastatin or vehicle injection, femurs with implants were evaluated with dual-energy X-ray absorp- tiometry, micro-computed tomography, scanning electron microscopy, quantitative analysis of screw around bone microstructure was operated. Observe the bone tissue structure around the bolt by scanning electron microscopy and toluidine blue staining. Measure the maximum load by the screw press and observe the ex- pression of BMP-2 by immunohistochemical staining.