脑损伤合并骨折与单纯骨折患者血管内皮生长因子的表达及其临床意义

背景:临床发现,脑损伤合并骨折有些部位骨痂过度生长,出现异位骨化,骨折愈合明显加快.目的:对比观察脑损伤合并骨折与单纯骨折两组患者骨折愈合过程骨痂中血管内皮生长因子的表达及分布,探讨临床意义及其作用机制.设计、时间及地点:分组对照观察,于2006-02/2007-07在解放军第四军医大学西京医院完成.对象:合并脑损伤组与单纯骨折组骨痂病理标本各50例.合并脑损伤组:男41例,女9例,年龄19～55岁;单纯骨折组:男36例,女14例,年龄17～52岁.方法:取两组患者各50例受伤7～10,11～15,16～20,21～27,28～35 d的骨痂标本,用免疫组织化学方法,检测两组患者不同时期骨痂标本中血管内皮生长因子含量高低,观察骨折愈合速度.主要观察指标:①X射线观察结果.②免疫组织化学染色图像分析.结果:在骨折愈合的不同阶段,两组骨痂内表达血管内皮生长因子的细胞来源一致,合并脑损伤组骨祖细胞、成骨细胞、软骨细胞中早期表达程度明显高于单纯骨折组,骨祖细胞增殖,成骨细胞、软骨细胞分化明显增加,7～10 d达到高峰,高峰持续30 d后逐渐减少:单纯骨折组在11～15 d出现高峰,高峰在20 d开始下降,峰值明显低于合并脑损伤组,配对t检验两组比较差异有显著性意义(P<0.05).合并脑损伤组在伤后4周即可见X射线片长骨骨折处大量骨痂生长,单纯骨折组在伤后7～9周才见到大量骨痂生长.结论:脑损伤合并骨折患者骨折愈合早期血管内皮生长因子表达显著强于单纯骨折患者,持续时间明显延长;血管内皮生长因子促进骨祖细胞增殖,成骨细胞、软骨细胞分化明显高于单纯骨折组;骨祖细胞增殖、成骨细胞及软骨细胞快速大量分化,是骨折快速愈合机制之一.

Expression of vascular endothelial growth factor in bony callus of patients with fracture combined with head injury versus simple fracture patients and its clinical significance

BACKGROUND: Clinical evidence have proved that heterotopic ossification is easily present in bony callus of patients with fracture combined with head injury, and the healing of bone fracture is accelerated obviously. OBJECTIVE: To study the expression and distribution of vascular endothelial growth factor (VEGF) in bony callus among the patients with fracture combined with head injury and simple fracture patients, and to investigate its clinical significance and action mechanism.DESIGN, TIME AND SETTING: Grouping controlled observation was performed in the Xijing Hospital, the Fourth Military Medical University of Chinese PLA between February 2006 and July 2007.PARTICIPANTS: The patients comprised two groups those who had fracture combined with head injury and those who had simple fracture. Each group had 50 patients. The fracture combined head injury group included 41 males and 9 females, aged 19-55 years; simple fracture group included 36 males and 14 females, aged 17-52 years. METHODS: The bony callus specimens were harvested at 7-10, 11-15, 16-20, 21-27 and 28-35 days post-injury. The content of VEGF in bony callus was measured at different phase by using immunohistochemistry methods, and the speed of fracture healing was also observed.MAIN OUTCOME MEASURES: ①X-ray results; ②immunohistochemical image analysis. RESULTS: In different phase of bone healing, the VEGF of the two groups were homogenous, the early expression of VEGF in osteoprogenitor cell, osteoblast and cartilage cell in the fracture combined with head injury group was significantly higher than those in simple fracture group. The osteoprogenitor cell proliferated, and the differentiations of osteoblast and cartilage cell were enhanced obviously. The VEGF level reached the peak at 7-10 days, and kept at the high level for 30 days and then gradually decreased. The peak of VEGF level in simple fracture group came at 11-15 days, kept in the high level for 20 days and then gradually decreased. The peak value in simple fracture group was significantly lower than the fracture combined with head injury group. There was statistical significance in the expression of VEGF between two groups by the paired t-test (P < 0.05). A large mount of osteotylus could be detected at 4 weeks after injury by X-ray in patients with fracture combined, with head injury, but at 7-9 weeks in patients of those who had simple fracture.CONCLUSION: The expression of VEGF in the bony callus in the group of fracture combined with head injury is significantly greater than that in simple fracture patients, and the expression lasts for a longer time. The proliferation and differentiation of osteogenitor call, osteoblast and cartilage cell are also significantly faster in the group of fracture combined with head injury, which might be one of the bone healing mechanisms.