【作者】 史永安；

【导师】 曹学成；

【作者基本信息】 泰山医学院 ， 外科学， 2009， 硕士

【摘要】 目的促进骨折愈合、减少并发症一直是骨科研究领域的热点问题。本实验旨在从骨形态计量学等方面阐述骨折扩髓后对髓内成骨过程的影响,评估骨折治疗过程中的再损伤,为临床治疗提供实验参考。材料与方法1.健康新西兰大白兔30只,制备双侧桡骨中段3mm骨缺损的骨折模型,为避免骨外膜对观察髓内成骨的影响,去除骨折端两侧各10mm骨外膜。实验按左右侧分为2组,每组30侧前肢。选择右侧作为实验组,进行扩髓处理;左侧为对照组,不扩髓。2.扩髓组,选用直径1.0-1.5mm微型磨钻自骨折端进入分别向桡骨近、远端扩髓;非扩髓组,保留原模型不做其他干预处理。3.分别于骨折后第2、4及8周,取标本进行大体组织观察、影像学观察、骨密度测定、骨痂病理组织学观察。结果1.X线摄片:实验侧术后2周骨折端血肿边缘有少许骨痂包绕,骨折间隙清晰;术后4周骨折界面模糊,有部分连接骨痂、封闭骨痂生成,髓腔未通;术后8周骨缺损明显,髓腔未通。对照侧术后2周骨折间隙模糊,有明显骨痂生长;术后4周连续性骨痂通过骨折线,骨痂已经开始塑形改造,髓腔部分开通;术后8周骨折线消失,骨干外形连续,骨髓腔已经基本恢复较规则。X线摄片评分分析表明,实验侧成骨速度明显慢于对照侧(p<0.01)。2.组织学:实验侧术后2周可见少量软骨细胞,成骨细胞数量少,有较多纤维肉芽组织;术后4周尚有软骨组织残留,夹存纤维骨痂,新生骨小梁排列紊乱,破骨细胞偶见,内骨痂少量;术后8周骨小梁排列方向不规则,髓腔未通,骨缺损明显。对照侧术后2周可见大量软骨细胞和纤维细胞,骨表面出现数目较多的成骨细胞,编织骨痂连接;术后4周骨改建已基本完成,并见到骨髓腔部分开通。骨性骨痂连接,大部分编织骨已被改建;术后8周骨髓腔完全开通,髓腔中可见大量髓细胞。3.骨密度:实验侧骨密度((BMD)在术后2, 4, 8周低于对照侧(p<0.01)。结论研究显示扩髓后内骨痂形成减少,髓内成骨过程延迟。扩髓对于长骨骨折髓内成骨过程破坏较大,产生的再损伤在临床治疗中应引起重视。更多还原

【Abstract】 ObjectiveTo promote fracture healing and reduce complication is the hot problem of research in orthopedics surgery .This experiment was to explain the effect of reaming on intramedullary osteogenesis in long bone, and to explore re-injury in fracture management.Methods1.Thirty New Zealand rabbits, aged from 3 to 5 months, weighing from 2.5kg to 3.0kg were used for the study. After bilateral radial defect of 3mm long was made, the periosteum of 10mm long near the fracture defect was removed .Forty anterior limbs were divided into two groups. In experimental group ,reaming was made with a drill of 1.0-1.5mm diameter, The control group was an unreaming one. By the end of 2nd,4th and 8th,anatomic observation, X-ray, bone mineral density(BMD),and histological examinations were made.Result1.X-ray imaging findings included less callus formation and clear fracture line in the experimental side, but more callus in the control side were found by the end of the 2nd week. Blurring fracture line remaining in the experimental side and disappearance of fracture line and bone union in the control side were found at the end of the 4th week .Bone defect and blocked bone marrow cavity in the experimental side and re-open of bone marrow cavity in the control side were found by the end of the 8th week. These X-ray assessments indicated bone formation in the experimental side were later than that in the control side (p<0.01).2.Histological findings included granulation tissue which was not completely replaced by fibrous tissue,spanocartilage between fragments of the fracture in the experimental side and active proliferation of osteoblast , fibrous connection, cartilage and newly formed bone trabeculae between fragments of the fracture in the control side by the end of the 2nd week; a lot of cartilage tissue increased woven bone in the experimental side and increased osteoblast, and connection of fractures in the control side by the end of the 4th week; woven bone between fragments of the fracture and defect in the experimental side and excellent remodeling of callus with lamellar bone,rechanellization of bone marrow cavity in the control side by the end of the 8th week.3.The bone mineral density (BMD) findings included lower- BMD in the experimental side than that in the control side by the end of the 2nd 4th and 8th week and significant difference between both sides (p<0.05).ConclusionsInternal callus formation was decreased intramedullary osteogenesis after reaming, the re-injury in fracture treatment should be emphasized.更多还原