胫骨骨折大鼠失神经支配条件下骨折愈合过程中最大载荷及静态骨计量学参数变化(英文)

Changes in the ultimate load and static bone histomorphometery parameters during the fracture healing process of denervated rats with tibial fracture

背景:临床观察表明,截瘫患者骨折常常愈合加快或在下肢有异位骨化形成,表明周围神经系统对骨折愈合有重要的调节作用。目的:观察一侧下肢失神经胫骨骨折愈合过程中骨计量学参数及骨痂形成和生物力学的变化。设计:自身对照动物实验。单位:天津医院。材料:健康雄性Wistar大鼠36只,6个月龄,平均体质量210g。方法:实验于2001-03/2004-03在天津医院动物实验中心完成。将大鼠一侧下肢制成失神经胫骨骨折模型,对侧制成正常神经支配骨折模型。骨折后2周、4周麻醉状态下处死大鼠,取双侧胫骨,拍X射线片、测定生物力学强度,制备不脱钙切片,进行骨计量学观察。主要观察指标:①两组大鼠骨折后双侧胫骨和骨痂湿质量比较。②X射线平片计分。③胫骨标本生物力学测试结果。④骨折愈合组织形态学观察。结果:①两组大鼠骨折后双侧胫骨和骨痂湿质量比较:骨折后2,4周失神经组重量远大于正常神经支配组[(0.94±0.15)比(0.76±0.14)g,(1.06±0.26)比(0.81±0.10)g,P<0.05]。②X射线平片计分结果:失神经组骨痂形成量明显增多(P<0.01)。③胫骨标本三点弯曲生物力学测试结果:骨折后2,4周失神经组骨痂的强度明显低于正常神经支配组[(9.88±8.49)比(16.62±13.38)N,(12.77±7.55)比(20.19±10.60)N,P<0.05]。④骨计量学检测结果:静态参数与正常神经支配组比较,失神经组矿化骨小梁宽度明显减小(P<0.05),类骨质宽度增加,破骨细胞指数及骨吸收表面明显增大(P<0.05),成骨细胞指数及骨形成表面两组无差别;动态参数与正常神经支配组比较,失神经组矿化沉积率明显变小(P<0.05),类骨质成熟时间延长(P<0.05)。结论:周围神经在骨折愈合早、中期起重要的调节作用,完整的神经支配是骨折愈合所必需的。

BACKGROUND： Clinical observation demonstrates that accelerated fracture healing or lower limb heterotopic ossifications always occur in patients with paraplegia. It indicates that peripheral nervous system may play an important role in fracture healing process. OBJECTIVE： To observe bone histomorphometery parameter, callus formation and biochemical change during the process of fracture healing of unilateral lower limb denervated tibia. DESIGN： Self-control animal experiment. SETTING： Tianjin Hospital. MATERIALS： Totally 36 six-month-old healthy male Wistar rats, with mean body mass of 210 g, were used in this experiment. METHODS： This experiment was carried out at Animal Experimental Center of Tianjin Hospital from March 2001 to March 2004. Denervated tibia fracture model and innervated tibia fracture model were made in the same rat. Animals were executed under anaesthetic status at week 2 and week 4 after fracture. Bilateral tibias were chosen to take radiografts. Biomachamical strength was measured and non-decalcification sections were prepared to perform bone histomorphometery observation. MAIN OUTCOME MEASURES： ① Comparison of wet weight of bilateral tibias and callus of rats between two groups after fracture. ②X-ray plain film scoring, ③ Biomechanical testing of tibial samples, ④ Histomorphological observation of fracture healing RESULTS： ① Wet weight of bilateral tibia and callus of rats in denervated group was much higher than that in innervated group at weeks 2 and 4 after fracture [（0.94±0.15） vs （0.76±0.14） g, （ 1.06±0.26）vs （0.81±0.10） g, P 〈 0.05]. ②In X-ray plain film scoring, callus formation was significantly increased in denervated group （P 〈 0.01）. ③In biomechanical testing of three-point bending of tibial sample, callus intensity was significantly lower at weeks 2 and 4 after fracture in denervated group than in innervated group[（9.88±8.49）vs （16.62±13.38） N, （ 12.77±7.55）vs （20.19±10.60） N, P 〈 0.05].④Bone histomorphometery showed that compared with innervated group, mineralized bone trabeeula width of denervated group was significantly reduced （P 〈 0.05）, osteoid width was increased , osteoclast index and bone absorption area were significantly increased （P 〈 0.05）, and there were no significant difference of fibroblast index and bone formation area between two groups; Compared with innervated group, mineralized deposition rate in the denervated group was significantly reduced （P 〈 0.05）, the mature time of osteoid was elongated （P 〈 0.05）. CONCLUSION： Peripheral nervous system may play an important role during early and middle period of fracture healing. Intact innervation is essential for normal fracture healing.