爆震伤合并大段骨缺损及海水浸泡外科治疗的实验研究

Treatment of explosive injury combined with bone defect using external fixation frame and artificial bone implant

[目的]探讨爆震伤合并大段骨缺损及海水浸泡的外科治疗方式并研究其成骨效果。[方法]以24只成年狗为实验对象,随机等量分为实验组与对照组,实验组对左后肢采用爆震致伤,截取狗后肢胫骨中段,形成2cm长的骨缺损,以海水浸泡伤肢1 h,经彻底清创后骨折端间植入医用纳米羟基磷灰石人工骨,骨折远近端以外固定架固定,对照组左后肢爆震致伤后,以同样方法造成2 cm长骨缺损,以海水浸泡伤肢1 h,彻底清创后不植入人工骨,同样以外固定架固定,两组均常规行预防感染治疗,术后4、8、12周分别摄X线片、组织切片、电镜检查及X射线能谱分析,观察成骨情况。[结果]实验组术后第4周可见新生编织骨;第8周可见大量巢状软骨细胞团及骨岛;第12周新生骨组织呈数个连续过渡的条带样分布区。随植入时间延长,植入体中钙/磷比值趋向于自体皮质骨。对照组骨折端钝圆,骨髓腔封闭,呈骨不愈合状态。[结论]应用外固定架和纳米羟基磷灰石人工骨植入可以有效治疗爆震伤合并大段骨缺损及海水浸泡的病例。

[Objective]To investigate surgical treatment and osteogenesis in explosive injury combined with bone defect initially treated by seawater immersion.[Method]The experimental subjects included 24 adult dogs,with the experimental group made up of all left posterior limbs and the control group made up of all right posterior limbs.In the experimental group,0.9 g cyclotrimethylene trinitramine was tied to the left posterior limb and detonated by an electrical stimulus.The bone was shortened by2 cm,and wounds were immersed in seawater for 1 h.After that,the wounds were cleaned completely and sutured.A nanohydroxyapatite artificial bone implant was grafted to the bone defect,and the fracture was stabilized with an external fixation frame.The control group received the same treatment as the experimental group except for that no artificial bone was implanted.The same evaluations were conducted in the experimental and control groups.All subjects were examined 4,8,12,and 24 weeks after the operation.Evaluations performed included radiography,histological analysis by hematoxylin-and-eosin staining and modified Masson trichrome staining,and scanning electron microscopy with energy-dispersive X-ray analysis.[Result]After4 weeks,woven bone was found in the experimental group.After 8 weeks,numerous nest-like chondrocyte masses and boneislands were found.After 12 weeks,newly formed bone arranged in a pattern of bands,containing bone cells in different transitional stages,was found.After 24 weeks,the ends of the implant and host bone were fused by cortical bone,and new bone marrow had invaded the implant.Furthermore,after the operation,the ratio of calcium to phos-phorus in the transplants approached that in the host cortical bone over time.[Conclusion]An external fixation frame and a nanohydroxyapatite artificial bone implant can be used to treat explosive injury combined with bone defect.