力生长因子对兔桡骨骨折愈合的作用

Effect of mechano growth factor on radial fracture healing in rabbits

背景:目前对力生长因子的研究主要集中在肌肉、神经损伤修复方面,并证实其可明显促进肌肉细胞肥大和神经修复。关于其对骨折愈合的作用还不清楚。目的:观察力生长因子对兔桡骨骨折愈合的作用。方法:随机数字表法将新西兰大白兔分为空白对照组、力生长因子低、高剂量组。通过手术造成大白兔左侧桡骨中段5mm完全缺损的骨折模型,术后第3天开始,各组分别予以PBS液及质量浓度为0.36,0.72g/L的力生长因子各0.2mL,经皮注射至骨折断端,连续注射5d,1次/d。术后第4,6,8周X射线观察骨折愈合情况。于术后第8周组织学观察各组骨折部位细胞形态学变化。结果与结论:术后第1天活动少,饮食量略减少,2d后基本恢复正常活动与饮食。3d内手术切口部位略有肿胀,少量渗血,无明显感染征象,12只兔全部进入结果分析。X射线显示,力生长因子高剂量组第4周时两骨折断端已基本结合在一起,骨皮质基本连续,骨折线模糊,第6周时骨髓腔已基本贯通,第8周时完全贯通,愈合时间较空白对照组、力生长因子低剂量组明显提前,愈合质量高。术后8周,空白对照组出现大量类骨组织,有少量编织骨形成,处于纤维性骨痂向骨性骨痂过度期;力生长因子低剂量组可见大量编织骨形成,处于骨性骨痂期;力生长因子高剂量组大量编织骨已改建为成熟的板层骨,已正处于骨痂改建期,与影像学结果一致。提示力生长因子具有明显促进骨折愈合的作用,并且在一定范围内随剂量的增大效果越明显。

BACKGROUND:Current research of mechano growth factor (MGF) mainly focuses on the muscles and nerve damage and repair,and it has been confirmed that MGF can promote muscle cell hypertrophy and nerve repair significantly. Regarding its role in fracture healing is unclear. OBJECTIVE:To investigate the effect of MGF on radial fracture healing in rabbits. METHODS:By using random digital table method,12 New Zealand rabbits were divided into 3 groups:blank control group,low-dose MGF group and high-dose MGF group. The models with 5 mm bone defect were produced in the middle of the left radius in rabbits. At 3 days after the surgical operation,the defective areas were given 0.2 mL PBS or 0.2 mL MGF (0.36 and 0.72 g/L) injected into the ends of fracture areas,respectively,once per day for continuous 5 days. At 4,6,8 weeks after operation,X-ray photography was used to evaluate the healing of fracture,and the histological examinations were performed at the 8th week to observe the cell morphology at the fracture lesion. RESULTS AND CONCLUSION:At 1 day after operation,the activities of rabbits were reduced,with slightly reduced food intake,at 2 days they almost recovered to normal activities and diet. At 3 days,the surgical incision slightly swelled with a small amount of bleeding and without obvious signs of infection. All 12 rabbits entered the final analysis. X-rays showed that two fracture ends have basically combined in the high-dose MGF group at 4 weeks post-surgery,cortical bone was continuous and fracture lines were unclear. At 6 weeks,the bone medullary cavity almost run through and fully run through at 8 weeks. The healing time in the high-dose MGF group was remarkably shorter than that in blank control group and low-dose MGF group,the healing was in high quality. At 8 weeks after operation,a large number of osteoid tissues were observed in the blank control group,a small amount of woven bone formed,at a transition period from the fibrous bone callus to the bony bone callus; a large number of woven bone formed in the low-dose MGF group,at bony bone callus period; in the high-dose MGF group,a large number of woven bones converted into mature lamellar bone,at the callus rebuilding phase,which was consistent with imaging results. It is indicated that MGF can accelerate fracture healing significantly in a rabbit model and shows a dose-dependent manner in a certain range.