低强度脉冲超声在骨-肌腱结合部纤维软骨带修复中的作用

目的 研究低强度脉冲超声(LIPUS)对兔髌骨-髌腱结合部(BTJ)愈合的影响.方法 建立兔部分髌骨切除模型,超声组在术后3天开始为期6周的LIPUS治疗;对照组在术后不给予治疗;通过组织学染色观察BTJ纤维软骨移行带的修复,并进行生物力学测试,以评估其疗效.结果 ①组织学结果显示,超声组术后6周在截骨界面有大量新骨生成,BTJ可见大量新生软骨细胞;术后12周纤维软骨带初步形成;术后18周可见具有过渡结构的纤维软骨带.而对照组术后6周纤维母细胞增生,无新骨形成;术后18周出现大量新生软骨细胞,但缺乏纤维软骨带的过渡结构.②术后6、12和18周的力学测量结果显示,各组BTJ随时间的推移而逐渐改建,三个时间点超声组的极限拉应力均明显高于对照组(P＜0.05).结论 LIPUS可使骨、软骨等多种细胞增生,通过促进新骨形成及重建纤维软骨带而加快骨肌腱结合部位的早期恢复.

Experimental study of low-intensity pulsed ultrasound stimulation on fibrocartilage zone of patellar bone-tendon junction healing

Objective To investigation the effect of low-intensity pulsed ultrasounds on healing of patellar bone-tendon junction. Methods Animal model of partial patellectomy were established and randomly classified into the ultrasound, and control groups, respectively. The ultrasound group was given low-intensity ultrasound therapy of 6 weeks at 3 days after operation. Observating the plerosis of BTJ the fibrous cartilage zone, and operating biomechanical examination to evaluate effects. Results In the ultrasound groups, the histological examination revealed there are plenty of newly born bones formation on the interface of cut bones at 6 weeks after operation. There are lots of newly born chondrocyte at BTJ. Fibrocartilage zone formed firstly at 12 weeks after operation. There are Fibrocartilage zones with transition structure at 18 weeks after operation. While in control group there are fibroblasts proliferation but no new bone formation at 6 weeks after operation, and occur plenty of new cartilage cells at 18 weeks after operation but lacks transition structure of Fibrocartilage zones. At three time points after operation, mechanics measuring results display that BTJ are gradually rebuilt in every group with the time advancing. The limit tensile stresses of the three time point in ultrasound group are larger than in control group (P<0.05). Conclusion Low-intensity ultrasound can make bone, cartilage cell and lots of others cell proliferating, accelerate new bone formation and rebuild transition structure of fibrocartilage zone, and so speed up early healing of bone-tendon junction.