低幅高频振动对骨质疏松性骨折合并闭合性动脉损伤的作用

目的利用卵巢切除大鼠建立骨质疏松骨折模型,研究低幅高频振动对骨质疏松性骨折愈合及患肢远端血供的作用。方法 32只6月龄雌性SD大鼠行卵巢切除术,3个月后构建右侧股骨干闭合性横行骨折合并股动脉损伤模型,术后随机平均分为振动组与对照组。每周摄股骨侧位X片以监测外骨痂尺寸及骨折愈合情况。第2、4、8周,应用脉冲多普勒超声测量患肢远端血流速度及阻力指数。Micro-CT扫描重建骨折部位,并作定性定量分析。结果超声检测发现,第2、4周振动组患肢股动脉远端收缩期峰值血流速度较对照组明显增高(P<0.05),阻力指数降低。X片及Micro-CT分析显示,振动组在愈合过程中,骨痂形成、矿化程度、重塑效果、桥接愈合率均显著优于对照组。结论低幅高频振动可有效改善患肢远端血供,促进骨质疏松性骨折愈合。

Effects of low-magnitude high-frequency vibration on osteoporotic fracture complicated by closed arterial injuries

Objective To investigate the effects of low-magnitude high-frequency vibration (LMHFV) on osteoporotic fracture healing and blood supply of distal injured limbs based on osteoporosis fracture model of the ovariectomized (OVX) rats. Methods Ovariectomy was performed in 32 six-month-old female SD rats. 3 months later, closed transverse fractures were created at the right femoral midshafts complicated by femoral artery injuries. The rats were then randomly divided into vibration group and control group. Radiographs were performed in each week to assess the callus size and the status of fracture healing. At 2nd, 4th and 8th week after treatment, pulsed-wave Doppler ultrasonography was utilized to evaluate the blood flow velocity and the resistance index (RI) of the distal femoral artery in injured limbs. The peri-fracture region was reconstructed by Micro-CT for both qualitative and quantitative analysis. Results Pulsed-wave Doppler indicated a significantly higher peak systolic velocity of distal femoral artery in vibration group at 2nd and 4th week (P<0.05) and a lower RI as compared with control group.Radiography and Micro-CT analysis demonstrated that vibration group had better callus formation, mineralization, remodeling, and bridging rate during fracture healing as compared with control group. Conclusions LMHFV can effectively improve the blood supply of distal injured limbs and promote the osteoporotic fracture healing.