这份出版物中的研究报告得到了国家卫生研究院的 F30AR071201 和 R01AR066028 的全国关节炎和肌肉骨骼和皮肤病研究所的支持。

这项议定书的制定是为了确保动物不被不必要地使用, 并幸免于一切不必要的痛苦和痛苦;它遵守所有适用的联邦、州、地方和机构的法律和指导动物研究的准则。该议定书是在一个由实验室动物医学专业兽医指导的大学范围内的实验动物医学计划的指引下制定的。该议定书得到了机构动物保育和使用委员会 (IACUC) 的审查和批准。
1. 断裂塔施工
注: 所有部件都列在材料部分 (材料表) 中。在补充图 1-12中, 为加工和3维印刷零件提供了详细的技术图纸。组件技术图纸包括所有安装部件的紧固件详细信息 (辅助图1、2、7和9)。
<ol><li>
支持子组件 注: 有关支持子组件的技术图, 请参阅辅助图 1。<ol>
<li>将光束支撑--横梁支撑中点的颚部- -水平截面。</li>
		<li>附加光束支撑- -垂直 1到光束支撑的顶面--颚部, 2 从光束支撑--水平剖面。</li>
		<li>将光束支撑--垂直 2到横梁支撑的顶面--中点的水平剖面(从末端 7)。</li>
		<li>连接梁, 支撑板安装到两端的横梁支架--垂直 1和横梁支撑--垂直 2。板支撑的端面应与横梁支承的背面齐平--垂直 2。</li>
	</ol>
</li>
	<li>
Ram 组件 注: 有关 ram 组件的技术图纸, 请参阅辅助图 2。<ol>
<li>机器的块停止和块指南(补充图 3);杆 Ram (辅助图 4);螺钉对准(辅助图 5);和板材安装(补充图 6)。</li>
		<li>将平板安装到横梁支架上--支撑子组件的板安装。</li>
		<li>按以下顺序滑动第一线性套筒轴承;块指南;第二线性套筒轴承;在拉杆 Ram上停止阻塞。将导轨和块连接到板上安装。</li>
		<li>将三⅜螺母连接到拉杆 Ram的螺纹部分。一个应该与杆的末端冲洗与电磁铁接触。另外2将用于调整裂缝深度。</li>
		<li>将拉杆 Ram中的小树林对准前方, 并将对准螺钉插入块导轨的螺纹孔中。</li>
	</ol>
</li>
	<li>
磁铁组件 注: 对于磁铁子组件的技术图纸, 请参阅辅助图 7。<ol>
<li>焊料电磁铁导致导线 (极性不是一个因素为电磁铁操作)。允许足够长的时间到达地板, 在那里骨折装置将被定位。使用拉链或另一种形式的附加应力减轻电线。</li>
		<li>剥离电源的末端, 并将其连接到脚踏板。最后, 将导线连接到脚踏板上的 "关闭" (通常是打开的) 配置。测试电路, 以确保电磁铁是在脚开关没有按下。这将使 ram 在骨折前保持。</li>
		<li>使用添加剂制造设备打印安装磁体(辅助图 8A和8B), 或从铝加工零件。</li>
		<li>将电磁铁连接到安装磁铁上。</li>
		<li>将 2角括号附加到光束支架上-磁铁。</li>
		<li>按以下顺序, 将拉杆磁铁穿过上角支架, 加入一个¼螺母;安装磁铁;两个¼的坚果;和底部角括号。在每个端上用两个¼螺母保护组件。</li>
	</ol>
</li>
	<li>
完整的组件 注: 有关完整组件的技术图纸, 请参阅辅助图 9。<ol>
<li>将磁体组件连接到横梁的顶面, 支撑板安装。</li>
		<li>调整光束支撑的对准-磁铁, 使磁铁与杆, Ram。 注: 如果杆不释放, 当踏板被按下, 减少接触面积之间的电磁铁和杆通过移动光束支持-磁铁。</li>
		<li>机器支架腿颚(辅助图 10)。</li>
		<li>将两个支架腿颚连接到横梁支架--颚部。当掉落时, ram 的尖端应该与每个颚的距离相等。</li>
		<li>将平台骨折(补充图 11A和11B) 置于颌骨上方。</li>
		<li>使用添加剂制造设备打印夹具定位断裂(辅助图 12A和12B) 和夹具销规(补充图 13A和13B), 或机器零件从铝。 注:夹具的尺寸将按步骤2中详细说明的优化步骤计算。</li>
		<li>将夹具定位断裂连接到平台断裂。</li>
		<li>确认撞击深度可以使用杆 Ram上的两个停止螺母进行调整。</li>
		<li>确认撞击速度可以通过上下移动安装磁体来调整。</li>
		<li>确认骨折的宽度可以通过移动方腿颚靠近或远离杆 Ram来调整。</li>
	</ol>
</li>
</ol>2. 断裂优化
<ol><li>断裂位置
	<ol>
<li>获得5例安乐死动物的代表性样品中骨折的肢体 (股骨或胫骨) 的影像。 注: 样品应与标本相匹配, 该样本将用于基于年龄、基因型和性别的实验性协议。即使最后的协议只要求一个骨折的肢体, 两个样本四肢将使用。</li>
		<li>将肢体切向 x 射线束, 以获得真实的侧向和前/后视图的骨骼。将已知维度的对象放置在成像平面上, 以提供用于分析的刻度。</li>
		<li>注: 如影像股骨, 确保肢体完全伸展, 股骨与胫骨在同一轴向平面。</li>
		<li>在要断开的肢体的射线照相上标记所需的骨折位置 (图 1条虚线)。测量从跟骨关节到明显骨折的水平 (图 1A)。计算所有试件的平均断裂长度 (FL)。股骨髁间凹槽的测量。</li>
	</ol></li>
	<li>断裂定位夹具
	<ol>
<li>测量从一个支撑铁砧的外部表面到断头台撞击 (CGI) 中心的距离 (图 2)。将CGI从FL中减去, 在步骤2.1.4 中描述, 以计算断裂定位夹具深度 (JD)。机器或 3 d-打印 U 形通道, 其高度和宽度等于铁砧, 深度等于JD (图 3a)。辅助图 12A和12B中包含了一个示例技术图纸和 CAD 文件。 注意: 当肢体被放置在夹具中时, 脚的背部应该与断头台撞击的表面距离最远。如果肢体需要额外的间隙, 请修改 U 形通道。</li>
		<li>将标本放置在骨折器械中, 用于股骨骨折或仰卧位胫骨骨折 (图 4)。将脚背压在骨折定位夹具的末端。手动压低断头台直到肢体骨折。获得骨折的肢体的射线照相, 以确认夹具大小和骨折位置 (图 2B)。</li>
		<li>增加jd如果骨折位置太远端骨, 或减少jd , 如果骨折位置太近骨。</li>
	</ol></li>
	<li>引脚参数的镇定
	<ol>
<li>
引脚长度:使用在步骤2.1 中获得的射线照相, 测量四肢长度(从胫骨高原到后踝的水平, 胫骨骨折, 或髁间凹槽到较大的转子股骨骨折。将骨骼长度乘以0.9 以计算 pin 长度 (PL) (图 1A和3B)。</li>
		<li>
针宽:使用步骤2.1 中获得的射线照相, 测量骨折肢体的最小髓质直径 (MD) (图 1A)。选择一针, 其尺寸大约相当于髓质直径, 长度超过 1.5 x PL。 注:14 周大的 C57BL/6J 鼠的大约针大小分别为股骨和胫骨的22克、1½和27克, 1¼。</li>
	</ol></li>
	<li>销切量规
	<ol>
<li>2.4.1 机器或 3 d 打印一个长度等于PL减去针长 (CGL) 的量规 (图 3B;补充图 13A及13B)。一端应该有一个悬臂, 以休息对针的中心, 另一个应该指出在哪里应该削减 pin。辅助图 13A和13B中包含了一个示例技术图纸和 CAD 文件。</li>
	</ol></li>
	<li>髓内针骨折稳定化
	<ol>
<li>使用步骤2.1 中的非骨折试验标本, 从胫骨中到股骨中移除毛发, 用电动剪或脱毛膏将头发取出, 露出膝关节。</li>
		<li>
胫骨钉扎: 插入针经皮侧的髌骨韧带。收回髌韧带内侧, 将针尖与胫骨轴对齐。使用扩孔运动, 轻轻地突破胫骨平台, 引导针下髓腔。</li>
		<li>
股骨钉: 插入针经皮侧的髌骨韧带。收回髌骨韧带内侧, 并将针尖与股骨髁间凹槽的轴线对齐。采用扩孔运动, 轻轻地突破髁间凹槽的关节面, 引导针下髓腔。</li>
		<li>使用步骤2.4 中制造的量规, 直到暴露的针等于测量长度。收回针提供足够的空间 (~ 3 毫米), 以削减针在水平指示的测量。 注: 一定要在切割时保持针的近端 (塑料) 末端, 所以它不会变成危险的弹丸。</li>
		<li>使用针刀将销的远端的0.3 毫米卷曲, 然后在量规的水平上切割针脚。使用直径大于针直径1.5x 的杆将引脚固定在关节表面。 注: 通过增加针骨接触, 压接可防止针的旋转和迁移。</li>
		<li>获得射线照相以确认针延长肢髓质管的长度, 不从近端或远端凸出 (图 1C)。</li>
	</ol></li>
	<li>冲击深度
	<ol>
<li>使用步骤2.1 中获得的射线照相, 测量所需骨折水平的皮层直径 (图 1A)。计算所有试验标本的平均皮质直径 (CD)。</li>
		<li>用步骤2.2 中制造的断裂定位夹具将骨折装置中步骤2.5 中的固定试件定位。将撞击 ram 放在未受伤的肢体上。 注意: 不要让 ram 掉下来;在这个优化步骤中, 骨骼应该保持完好。</li>
		<li>在 ram 上施加足够的向下力来压缩软组织, 但不能骨折骨。将撞击深度 (ID) 调整为 0.75 x CD (图 2)。 注: 理想的撞击深度为 0.5 x CD , 当骨折时没有任何软组织。使用0.75 帐户进行额外的软组织压缩。</li>
	</ol></li>
	<li>砧宽
	<ol>
<li>为小鼠胫骨或股骨设置砧宽 (AW) 为0.4 厘米 (图 2)。 注意: 建议更宽的宽度, 如大鼠等较大的标本。</li>
	</ol></li>
	<li>Ram 重量
	<ol>
<li>建议对小鼠标本的最小重量为250克。 注意: 额外的重量可以被螺纹到 ram 为更大的标本 (图 2)。</li>
	</ol></li>
	<li>冲击速度
	<ol>
<li>将放置高度 (DH) 设置为2厘米 (图 2)。将 ram 放置在其起始位置, 将其连接到活化电磁铁。</li>
		<li>在骨折装置中放置一个试肢。将脚背按在步骤2.2 中制造的骨折定位夹具上。简要地压低脚踏开关释放 ram, 然后将其重置为其起始位置。</li>
		<li>对受影响的试验肢体进行射线照相。分析肢体骨折的任何证据 (图 1D)。 注意: 当使用具有受控冲击深度的低速速度时, 这可能是微妙的。</li>
		<li>如果未生成任何断开, 请重复步骤 2.9.1 2.9.3, 并将放置高度增加2厘米。</li>
		<li>如果生成断开, 则记录下拉高度, 并将其乘以1.1。这是新生署。</li>
		<li>使用DH从步骤 2.9.5, 骨折的下一个试验肢体。</li>
		<li>如果未生成任何断开, 请重复步骤 2.9.1 2.9.6, 并将放置高度增加2厘米。</li>
		<li>如果生成了断开, 请重复步骤 2.9.6 2.9.7, 直到使用所有测试示例。从优化中记录最终的DH和所有参数 (FL、 CGI、 JD、 PL、 MD、 PS、 CGL、 CD、 ID、 AW和cd-rw)。记录试验标本的年龄、性别、基因型和体重。</li>
	</ol></li>
</ol>3. 闭合稳定的断裂世代
<ol><li>
设置
	<ol>
<li>通过高压釜、热珠浸泡或其等效物灭菌所有设备和仪器。</li>
		<li>将加热元件放在手术台上, 并将其设置为最佳温度。用外科悬垂盖住这个元素。在2的外科悬垂中准备 3 x 3, 在中间切开一个0.75 英寸的圆圈。</li>
		<li>在每次试验前确认裂缝塔的调整 (图 2)。将ID、 AW、 cd-rw和DH设置为要研究的样本中特定于性别、年龄和基因型的优化协议中的值。</li>
		<li>权衡和记录动物的重量。</li>
	</ol>
</li>
	<li>
手术
	<ol>
<li>用吸入麻醉药 (异氟醚: 4-5% 进行诱导; 1-2% 用于维护) 或另一种已建立的实验室麻醉协议, 使鼠标充分镇静。呼吸率应为 55-100 呼吸/分钟。动物不应该对后肢脚趾捏起反应。</li>
		<li>管理术后镇痛的第一剂量丁丙诺啡 (0.1 毫克/千克皮下)。</li>
		<li>应用眼部润滑, 防止角膜干燥。</li>
		<li>用电动剪刀从胫骨中到股骨中移除动物的毛发, 露出膝盖关节。使用无反应胶带清洁多余毛发的部位。用70% 乙醇湿拭子准备固定部位。必要时重复清除切口区域的所有毛发。</li>
		<li>用聚维酮碘和70% 乙醇的替代拭子制备和清洁固定区域。使用两个替代拭子序列, 以确保不孕。</li>
		<li>在皮肤经过适当消毒后, 在手术部位放置一个悬垂。</li>
		<li>使用步骤2.5 中描述的协议将肢体折断。获得射线照相, 以确认针延长髓质管长度, 但不突出从近端或远端。</li>
		<li>打开电磁铁并连接撞击 ram 将其放置在起始位置。</li>
		<li>将标本放置在骨折器械中, 将其置于股骨骨折或仰卧位胫骨骨折的俯卧位。固定的肢体应放置在铁砧和在骨折定位夹具与背部的脚压在夹具外。</li>
		<li>当一只手按下脚, 并确保只有肢体在撞击 ram 目标区域, 简要地压低脚踏开关释放 ram。替换起始位置的 ram。</li>
		<li>获取射线照相并确认骨折位置和类型。</li>
	</ol>
</li>
	<li>
术后管理
	<ol>
<li>监测动物每15分钟从麻醉恢复, 直到动物意识, 可以保持胸骨卧床, 是动态的。确认动物能在72小时内走动。</li>
		<li>将动物单独饲养, 直到完全恢复。</li>
		<li>在48小时内保持镇痛, 每12小时服用丁丙诺啡 (0.1 毫克/千克)。</li>
		<li>监测和记录动物的健康状况每日 7-10 d 或直到安乐死。</li>
	</ol>
</li>
	<li>
断裂后分析
	<ol>
<li>测量FL、 PL、 CD、 MD和断裂模式。记录主数据文件中的度量值。</li>
	</ol>
</li>
</ol>

<ol>
	<li>Corso, P., Finkelstein, E., Miller, T., Fiebelkorn, I., Zaloshnja, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incidence+and+lifetime+costs+of+injuries+in+the+United+States.">Incidence and lifetime costs of injuries in the United States.</a> Injury Prevention. 12 (4), 212-218 (2006).</li><li>Nguyen, N. D., Ahlborg, H. G., Center, J. R., Eisman, J. A., Nguyen, T. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+lifetime+risk+of+fractures+in+women+and+men.">Residual lifetime risk of fractures in women and men.</a> Journal of Bone and Mineral Research: The Official Journal of the American Society for Bone and Mineral Research. 22 (6), 781-788 (2007).</li><li>Thompson, Z., Miclau, T., Hu, D., Helms, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+model+for+intramembranous+ossification+during+fracture+healing.">A model for intramembranous ossification during fracture healing.</a> Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society. 20 (5), 1091-1098 (2002).</li><li>Cheung, K. M. C., Kaluarachi, K., Andrew, G., Lu, W., Chan, D., Cheah, K. S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+externally+fixed+femoral+fracture+model+for+mice.">An externally fixed femoral fracture model for mice.</a> Journal of Orthopaedic Research. 21 (4), 685-690 (2003).</li><li>Connolly, C. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+reliable+externally+fixated+murine+femoral+fracture+model+that+accounts+for+variation+in+movement+between+animals.">A reliable externally fixated murine femoral fracture model that accounts for variation in movement between animals.</a> Journal of Orthopaedic Research. 21 (5), 843-849 (2003).</li><li>Histing, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+internal+locking+plate+to+study+intramembranous+bone+healing+in+a+mouse+femur+fracture+model.">An internal locking plate to study intramembranous bone healing in a mouse femur fracture model.</a> Journal of Orthopaedic Research. 28 (3), 397-402 (2010).</li><li>Gr&#246;ngr&#246;ft, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fixation+compliance+in+a+mouse+osteotomy+model+induces+two+different+processes+of+bone+healing+but+does+not+lead+to+delayed+union.">Fixation compliance in a mouse osteotomy model induces two different processes of bone healing but does not lead to delayed union.</a> Journal of Biomechanics. 42 (13), 2089-2096 (2009).</li><li>Bonnarens, F., Einhorn, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+a+standard+closed+fracture+in+laboratory+animal+bone.">Production of a standard closed fracture in laboratory animal bone.</a> Journal of Orthopaedic Research. 2 (1), 97-101 (1984).</li><li>Huang, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+spatiotemporal+role+of+COX-2+in+osteogenic+and+chondrogenic+differentiation+of+periosteum-derived+mesenchymal+progenitors+in+fracture+repair.">The spatiotemporal role of COX-2 in osteogenic and chondrogenic differentiation of periosteum-derived mesenchymal progenitors in fracture repair.</a> PloS One. 9 (7), 100079 (2014).</li><li>Waki, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Profiling+microRNA+expression+during+fracture+healing.">Profiling microRNA expression during fracture healing.</a> BMC Musculoskeletal Disorders. 17, 83 (2016).</li><li>Yee, C. 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M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Does+Anticoagulant+Medication+Alter+Fracture-Healing?+A+Morphological+and+Biomechanical+Evaluation+of+the+Possible+Effects+of+Rivaroxaban+and+Enoxaparin+Using+a+Rat+Closed+Fracture+Model.">Does Anticoagulant Medication Alter Fracture-Healing? A Morphological and Biomechanical Evaluation of the Possible Effects of Rivaroxaban and Enoxaparin Using a Rat Closed Fracture Model.</a> PloS One. 11 (7), 0159669 (2016).</li><li>Menzdorf, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Local+pamidronate+influences+fracture+healing+in+a+rodent+femur+fracture+model:+an+experimental+study.">Local pamidronate influences fracture healing in a rodent femur fracture model: an experimental study.</a> BMC Musculoskeletal Disorders. 17, 255 (2016).</li><li>Hagiwara, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fixation+stability+dictates+the+differentiation+pathway+of+periosteal+progenitor+cells+in+fracture+repair.">Fixation stability dictates the differentiation pathway of periosteal progenitor cells in fracture repair.</a> Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society. 33 (7), 948-956 (2015).</li><li>Gardner, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+fracture+healing+resulting+from+fixation+stiffness+variability:+a+mouse+model.">Differential fracture healing resulting from fixation stiffness variability: a mouse model.</a> Journal of Orthopaedic Science: Official Journal of the Japanese Orthopaedic Association. 16 (3), 298-303 (2011).</li><li>Catma, M. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remote+ischemic+preconditioning+enhances+fracture+healing.">Remote ischemic preconditioning enhances fracture healing.</a> Journal of Orthopaedics. 12 (4), 168-173 (2015).</li><li>Lichte, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impaired+Fracture+Healing+after+Hemorrhagic+Shock.">Impaired Fracture Healing after Hemorrhagic Shock.</a> Mediators of Inflammation. 2015, 132451 (2015).</li><li>Lopas, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fractures+in+geriatric+mice+show+decreased+callus+expansion+and+bone+volume.">Fractures in geriatric mice show decreased callus expansion and bone volume.</a> Clinical Orthopaedics and Related Research. 472 (11), 3523-3532 (2014).</li><li>Bonnarens, F., Einhorn, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+a+standard+closed+fracture+in+laboratory+animal+bone.">Production of a standard closed fracture in laboratory animal bone.</a> Journal of orthopaedic research. 2 (1), 97-101 (1984).</li><li>Marturano, J. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+improved+murine+femur+fracture+device+for+bone+healing+studies.">An improved murine femur fracture device for bone healing studies.</a> Journal of Biomechanics. 41 (6), 1222-1228 (2008).</li><li>Jackson, R. W., Reed, C. A., Israel, J. A., Abou-Keer, F. K., Garside, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+a+standard+experimental+fracture.">Production of a standard experimental fracture.</a> Canadian Journal of Surgery. Journal Canadien De Chirurgie. 13 (4), 415-420 (1970).</li><li>Byrne, M., Cleveland, B., Marturano, J., Wixted, J., Billiar, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+of+a+reproducible+murine+femoral+fracture+device.+Conference:+Bioengineering+Conference,+2007.">Design of a reproducible murine femoral fracture device. Conference: Bioengineering Conference, 2007.</a> NEBC '07. IEEE 33rd Annual Northeast. , (2007).</li><li>Carter, D. R., Hayes, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compact+bone+fatigue+damage-I.+Residual+strength+and+stiffness.">Compact bone fatigue damage-I. Residual strength and stiffness.</a> Journal of Biomechanics. 10 (5), 325-337 (1977).</li><li>McGee, A., Qureshi, A., Porter, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+of+the+biomechanics+and+patterns+of+limb+fractures.">Review of the biomechanics and patterns of limb fractures.</a> Trauma. 6 (1), 29-40 (2004).</li></ol>

作者没有什么可透露的。

这种断裂优化和生成协议为研究人员提供了一种有效的方法来获得骨折参数和执行一个微创程序, 产生精确, 可重复, 横向骨折。此外, 该协议还建立了一组常见的断裂生成参数, 从而促进了研究人员之间的方法一致性。这些参数将使创建一个常见的断开数据库, 根据各种参数 (如年龄、性别、性别和基因型) 建立骨折标准。对断裂变量的优化显著降低了样本异质性-减少了浪费时间、资源丢失?...

骨折愈合的研究对于解决大的临床和经济问题是必要的。每年有1200万多起骨折在美国治疗1, 成本为800亿美元2。男性或女性在其一生中遭受骨折的可能性为25% 和 44%, 分别为3。随着并发症的增加, 随着年龄的增长, 骨折愈合的相关问题将会增加。为了研究和解决这一问题, 需要建立可靠的断裂产生和稳定模型。啮齿类动物模型是理想地适合这个目的。它们提供临床相关性, 可以修改以解决特定的情况 (即多发伤、开放性、闭合性、缺血性和感染性骨折)。除了复制临床情况外, 动物骨折模型对于了解骨骼生物学和开发治疗和设备是很重要的。然而, 试图研究干预之间的差异可能是复杂的变异引入不一致的断裂产生。因此, 在动物模型中产生可重现和持续闭合的骨折, 对于肌肉骨骼研究领域是必不可少的。
尽管通过确保适当的遗传背景、性别、年龄和环境条件, 适当控制潜在的主体异质性, 但临床相关的一致骨损伤的产生是一个重要变量, 影响必须控制的重现性。使用不一致的裂缝进行统计比较, 实验噪声和高变异性4;此外, 骨折变异性可能导致不必要的动物死亡, 因为需要增加样本大小或必要的弄死动物的粉碎或 malpositioned 骨折。本文所述方法的目的是优化特定于样本类型的断裂生成参数, 并产生一致的断裂位置和模式。
目前的断裂产生模型分为两大类, 各有优缺点。开放性骨折 (截骨) 模型进行手术暴露骨, 之后骨折是由切割骨或削弱它, 然后手动打破它5,6,7,8。该方法的优点是裂缝部位的直接可视化, 以及更一致的断裂位置和模式。然而, 损伤途径和机制的生理和临床相关性是有限的。此外, 开放性骨折产生的方法需要手术方法和关闭的长期期间, 啮齿类动物暴露在增加的危险的污染。
封闭技术解决了许多开放技术的局限性。闭合技术产生骨折使用外部应用钝力损伤, 导致损伤的骨骼和周围组织, 更类似于人的临床损伤。最常见的方法是 Bonnarens 和埃霍恩在 1984年9描述。他们描述了一个加权断头台被用来传授钝外伤, 以打破骨骼, 而不造成任何外部皮肤创伤。该方法已广泛应用于研究遗传学 10、11、药理治疗12、13、14、15、力学16的效果,17、生理学18、19、20对小鼠和大鼠骨愈合的影响。闭合方法的好处是生理上相关的断裂, 实验的重现性和严密是受断裂非均质的限制。不一致的断裂产生的结果是有限的组间分化, 失去标本, 并增加动物需要达到统计学意义。
控制断裂产生和稳定的变异性是产生有意义结果的必要条件。为了正确研究骨折修复的生物学, 需要一个简单而健壮的断裂模型。该模型应可翻译为啮齿动物物种, 骨骼类型 (例如股骨或胫骨), 并跨越可变的小鼠遗传背景和诱发突变。此外, 理想的程序应该在技术上简单, 并产生一致的结果。为解决骨折异质性, 本文所描述的方法是构造一个良好的控制骨折装置, 然后可以用来优化参数和产生一致闭合的骨折, 无论年龄, 性别, 或基因型。

<table><tbody><tr><td>&lt;strong&gt;Support Subassembly&lt;/strong&gt;</td><td></td><td></td><td>Supplementary Figure 1</td></tr><tr><td>Beam, Support--Jaw Section&amp;nbsp;</td><td>80/20</td><td>1003 x 9.00</td><td>w/ #7042 at A, C, in Left End</td></tr><tr><td>Beam, Support--Horizontal Section</td><td>80/20</td><td>1002 x 14.00</td><td></td></tr><tr><td>Beam, Support--Vertical 1</td><td>80/20</td><td>1050 x 10.50&amp;nbsp;</td><td>w/ #7042 at A in Left End and at A in Right End</td></tr><tr><td>Beam, Support--Vertical 2</td><td>80/20</td><td>1010 x 10.50&amp;nbsp;</td><td>w/ #7042 at D, B in Left End and at A in Right End</td></tr><tr><td>Beam, Support--Plate Mount</td><td>80/20</td><td>1030 x 8.00&amp;nbsp;</td><td>w/ #7036 at Left End</td></tr><tr><td>Beam, Support--Magnet</td><td>80/20</td><td>1010 x 13.50&amp;nbsp;</td><td>w/ #7042 at A, C, in Right End</td></tr><tr><td>Anchors (3)</td><td>80/20</td><td>3392</td><td></td></tr><tr><td>Double Anchor (3)</td><td>80/20</td><td>3091</td><td></td></tr><tr><td>Bolt Assembly (6)</td><td>80/20</td><td>3386</td><td>1/4-20 x 3/8&quot;</td></tr><tr><td>Button Head Socket Cap Screw (6)</td><td>80/20</td><td>3604</td><td>1/4-20 x 3/4&quot;</td></tr><tr><td>&lt;strong&gt;Ram Subassembly&lt;/strong&gt;</td><td></td><td></td><td>Supplementary Figure 2</td></tr><tr><td>Block, Stop</td><td>Custom</td><td></td><td>Supplementary Figure 3</td></tr><tr><td>Block, Guide</td><td>Custom</td><td></td><td>Supplementary Figure 3</td></tr><tr><td>Rod, Ram</td><td>Custom</td><td></td><td>Supplementary Figure 4</td></tr><tr><td>Alignment Screw</td><td>Custom</td><td></td><td>Supplementary Figure 5</td></tr><tr><td>Plate, Mounting</td><td>Custom</td><td></td><td>Supplementary Figure 6</td></tr><tr><td>Linear Sleeve Bearing (2)</td><td>McMaster-Carr</td><td>8649T2</td><td></td></tr><tr><td>Hex Nut (3)</td><td>McMaster-Carr</td><td>92673A125</td><td>3/8-16 UNC</td></tr><tr><td>Socket Cap Screw (8)</td><td>McMaster-Carr</td><td>92196A108</td><td>4/40 x 3/8&quot;</td></tr><tr><td>Socket Cap Screw (6)</td><td>McMaster-Carr</td><td>92196A032</td><td>4/40 x 1 1/8&quot;</td></tr><tr><td>Socket Cap Screw (1)</td><td>McMaster-Carr</td><td>92196A267&amp;nbsp;</td><td>10/32 3/8&quot;</td></tr><tr><td>&lt;strong&gt;Magnet Subassembly&lt;/strong&gt;</td><td></td><td></td><td>Supplementary Figure 7</td></tr><tr><td>Mount, Magnet</td><td>Custom</td><td></td><td>Supplementary Figure 8</td></tr><tr><td>Power Supply</td><td>McMaster-Carr</td><td>70235K23</td><td></td></tr><tr><td>Foot Switch</td><td>McMaster-Carr</td><td>7376k2</td><td></td></tr><tr><td>Electromagnet</td><td>McMaster-Carr</td><td>5698k111</td><td></td></tr><tr><td>Wire - 10 feet</td><td>McMaster-Carr</td><td>9936k12</td><td></td></tr><tr><td>Rod, Magnet</td><td>McMaster-Carr</td><td>95412A566</td><td>1/4&quot; Threaded Rod x 7&quot;</td></tr><tr><td>Corner Bracket (6)</td><td>80/20</td><td>4108</td><td></td></tr><tr><td>Socket Cap Screw (1)</td><td>McMaster-Carr</td><td>92196A705</td><td>10/32 1 1/4&quot;</td></tr><tr><td>Hex Nut (4)</td><td>McMaster-Carr</td><td>92673A113</td><td>1/4-20 UNC</td></tr><tr><td>&lt;strong&gt;Complete Assembly&lt;/strong&gt;</td><td></td><td></td><td>Supplementary Figure 9</td></tr><tr><td>Bracket, Leg Jaw (2)</td><td>Custom</td><td></td><td>Supplementary Figure 10</td></tr><tr><td>Platform, Fracture</td><td>Custom</td><td></td><td>Supplementary Figure 11</td></tr><tr><td>Jig, Positioning-Fracture</td><td>Custom</td><td></td><td>Supplementary Figure 12</td></tr><tr><td>&lt;strong&gt;Other&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Pin Cutter</td><td>Medical Supplies and Equipment</td><td>150S</td><td></td></tr><tr><td>Needles</td><td>Sigma</td><td>Z192430, Z192376&amp;nbsp;</td><td>23g x 1.5&quot; - mouse femur, 27g x 1.25&quot; - mouse tibia</td></tr></tbody></table>

fracture apparatus design and protocol optimization for closed-stabilized fractures in rodents

在动物模型中可靠地生成一致稳定的骨折, 对于了解骨再生生物学和开发治疗方法和装置是必不可少的。然而, 现有的伤害模型受到不一致的困扰, 造成动物和资源的浪费和数据不完善。为了解决断裂异质性的问题, 本文所述方法的目的是优化每种动物的断裂生成参数, 并产生一致的断裂位置和模式。该协议说明了在小鼠菌株之间可能存在的骨骼大小和形态学的变化, 并且可以适应于其他物种 (如老鼠) 产生一致的骨折。此外, 还介绍了一种经济高效、可调节的断裂装置。与目前稳定的断裂技术相比, 优化方案和新的断裂装置表明, 稳定断裂模式和位置的一致性增加。通过使用特定于样本类型的优化参数, 所述协议提高了诱发创伤的精确度, 最大限度地减少了闭合断裂生成过程中通常观察到的断裂异质性。

以前在我们实验室使用的断头台是在2004年开发的, 是基于埃霍恩21出版的模型。该设计不允许调整, 以充分考虑任何差异的骨骼形态学和不允许可重复的定位的肢体。此外, 以前的仪器需要两个人来操作它。因此, 我们设计, 工程, 并建立了一个新的断裂装置。主要设计目标是可能的高保真度调整的裂缝深度, 冲击力, 三点接触, 和动物定位。该设计基于 Martur...

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Fracture Apparatus Design and Protocol Optimization for Closed-stabilized Fractures in Rodents

该协议的目标是优化裂缝产生参数, 以产生一致的裂缝。这项协议解释了动物之间可能存在的骨骼大小和形态学的变化。此外, 还介绍了一种经济高效、可调节的断裂装置。

鼠类闭合稳定骨折的断裂装置设计与协议优化

The reliable generation of consistent stabilized fractures in animal models is essential for understanding the biology of bone regeneration and developing ...

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13.3K 次观看.  Michigan State University. 该协议的目标是优化裂缝产生参数, 以产生一致的裂缝。这项协议解释了动物之间可能存在的骨骼大小和形态学的变化。此外, 还介绍了一种经济高效、可调节的断裂装置。

视频: Fracture Apparatus Design and Protocol Optimization for Closed-stabilized Fractures in Rodents

Pseudofracture: An Acute Peripheral Tissue Trauma Model

Following trauma there is an early hyper-reactive inflammatory response that can lead to multiple organ dysfunction and high mortality in trauma patients; this response is often accompanied by a delayed immunosuppression that adds the clinical complications of infection and can also increase mortality.1-9 Many studies have begun to assess these changes in the reactivity of the immune system following trauma.10-15 
Immunologic studies are greatly supported through the wide variety of transgenic and knockout mice available for in vivo modeling; these strains aid in detailed investigations to assess the molecular pathways involved in the immunologic responses.16-21
The challenge in experimental murine trauma modeling is long term investigation, as fracture fixation techniques in mice, can be complex and not easily reproducible.22-30
This pseudofracture model, an easily reproduced trauma model, overcomes these difficulties by immunologically mimicking an extremity fracture environment, while allowing freedom of movement in the animals and long term survival without the continual, prolonged use of anaesthesia. The intent is to recreate the features of long bone fracture; injured muscle and soft tissue are exposed to damaged bone and bone marrow without breaking the native bone.
The pseudofracture model consists of two parts: a bilateral muscle crush injury to the hindlimbs, followed by injection of a bone solution into these injured muscles. The bone solution is prepared by harvesting the long bones from both hindlimbs of an age- and weight-matched syngeneic donor. These bones are then crushed and resuspended in phosphate buffered saline to create the bone solution.
Bilateral femur fracture is a commonly used and well-established model of extremity trauma, and was the comparative model during the development of the pseudofracture model. Among the variety of available fracture models, we chose to use a closed method of fracture with soft tissue injury as our comparison to the pseudofracture, as we wanted a sterile yet proportionally severe peripheral tissue trauma model. 31
Hemorrhagic shock is a common finding in the setting of severe trauma, and the global hypoperfusion adds a very relevant element to a trauma model. 32-36 The pseudofracture model can be easily combined with a hemorrhagic shock model for a multiple trauma model of high severity. 37

Pseudofracture, a reproducible murine model of sterile musculoskeletal trauma, allows for evaluation of late term post-traumatic immune responses. This article describes the procedural execution of the model step by step, including the potential for experimental model combinations to permit study of multiple trauma.

Pseudofracture：急性周围组织的创伤模型

Following trauma there is an early hyper-reactive inflammatory response that can lead to multiple organ dysfunction and high mortality in trauma patients; ...

科研

医学

Creating Rigidly Stabilized Fractures for Assessing Intramembranous Ossification, Distraction Osteogenesis, or Healing of Critical Sized Defects

Assessing modes of skeletal repair is essential for developing therapies to be used clinically to treat fractures. Mechanical stability plays a large role in healing of bone injuries. In the worst-case scenario mechanical instability can lead to delayed or non-union in humans. However, motion can also stimulate the healing process. In fractures that have motion cartilage forms to stabilize the fracture bone ends, and this cartilage is gradually replaced by bone through recapitulation of the developmental process of endochondral ossification. In contrast, if a bone fracture is rigidly stabilized bone forms directly via intramembranous ossification. Clinically, both endochondral and intramembranous ossification occur simultaneously. To effectively replicate this process investigators insert a pin into the medullary canal of the fractured bone as described by Bonnarens4. This experimental method provides excellent lateral stability while allowing rotational instability to persist. However, our understanding of the mechanisms that regulate these two distinct processes can also be enhanced by experimentally isolating each of these processes. We have developed a stabilization protocol that provides rotational and lateral stabilization. In this model, intramembranous ossification is the only mode of healing that is observed, and healing parameters can be compared among different strains of genetically modified mice 5-7, after application of bioactive molecules 8,9, after altering physiological parameters of healing 10, after modifying the amount or time of stabilization 11, after distraction osteogenesis 12, after creation of a non-union 13, or after creation of a critical sized defect. Here, we illustrate how to apply the modified Ilizarov fixators for studying tibial fracture healing and distraction osteogenesis in mice.

This article describes a method for stabilizing long bone fractures that is based on the application of modified Ilizarov external fixators 1-3. After application of the fixators and creation of the bone injury, healing can be assessed, distraction osteogenesis can be performed, or non-union or critical sized defect can be created and used to study therapeutic interventions.

建立评估膜内骨化硬性稳定骨折，牵张成骨，或临界中小企业缺损愈合

Assessing modes of skeletal repair is essential for developing therapies to be used clinically to treat fractures. Mechanical stability plays a large role ...

An Efficient and Reproducible Protocol for Distraction Osteogenesis in a Rat Model Leading to a Functional Regenerated Femur

This protocol describes the use of a newly developed external fixator for distraction osteogenesis in a rat femoral model. Distraction osteogenesis (DO) is a surgical technique leading to bone regeneration after an osteotomy. The osteotomized extremities are moved away from each other by gradual distraction to reach the desired elongation. This procedure is widely used in humans for lower and upper limb lengthening, treatment after a bone nonunion, or the regeneration of a bone defect following surgery for bone tumor excision, as well as in maxillofacial reconstruction. Only a few studies clearly demonstrate the efficiency of their protocol in obtaining a functional regenerated bone, i.e., bone that will support physiological weight-bearing without fracture after removal of the external fixator. Moreover, protocols for DO vary and reproducibility is limited by lack of information, making comparison between studies difficult. The aim of this study was to develop a reproducible protocol comprising an appropriate external fixator design for rat limb lengthening, with a detailed surgical technique that permits physiological weight-bearing by the animal after removal of the external fixator.

This study describes a reproducible and detailed protocol using a newly developed external fixator for distraction osteogenesis (DO) in a femoral rat model which permits physiological weight-bearing by the animal after removal of the external fixator.

大鼠牵张成骨的高效可再生性协议

This protocol describes the use of a newly developed external fixator for distraction osteogenesis in a rat femoral model. Distraction osteogenesis (DO) ...

生物工程

A Reliable and Reproducible Critical-Sized Segmental Femoral Defect Model in Rats Stabilized with a Custom External Fixator

Orthopedic research relies heavily on animal models to study mechanisms of bone healing in vivo as well as investigate the new treatment techniques. Critical-sized segmental defects are challenging to treat clinically, and research efforts could benefit from a reliable, ambulatory small animal model of a segmental femoral defect. In this study, we present an optimized surgical protocol for the consistent and reproducible creation of a 5 mm critical diaphyseal defect in a rat femur stabilized with an external fixator. The diaphyseal ostectomy was performed using a custom jig to place 4 Kirschner wires bicortically, which were stabilized with an adapted external fixator device. An oscillating bone saw was used to create the defect. Either a collagen sponge alone or a collagen sponge soaked in rhBMP-2 was implanted into the defect, and the bone healing was monitored over 12 weeks using radiographs. After 12 weeks, rats were sacrificed, and histological analysis was performed on the excised control and treated femurs. Bone defects containing only collagen sponge resulted in non-union, while rhBMP-2 treatment yielded the formation of a periosteal callous and new bone remodeling. Animals recovered well after implantation, and external fixation proved successful in stabilizing the femoral defects over 12 weeks. This streamlined surgical model could be readily applied to study bone healing and test new orthopedic biomaterials and regenerative therapies in vivo.

In vivo mammalian models of critical-sized bone defects are essential for researchers studying healing mechanisms and orthopedic therapies. Here, we introduce a protocol for the creation of reproducible, segmental, femoral defects in rats stabilized using external fixation.

一种可靠、可重复的可重复的大鼠部分股骨缺陷模型

Orthopedic research relies heavily on animal models to study mechanisms of bone healing in vivo as well as investigate the new treatment techniques. ...

A Mouse Model of Orthopedic Surgery to Study Postoperative Cognitive Dysfunction and Tissue Regeneration

Surgery is commonly used to improve and maintain quality of life. Unfortunately, in vulnerable patients such as the elderly, complications may occur and significantly diminish the outcome. Indeed, after routine orthopedic surgery to repair a fracture, as many as 50% of elderly patients suffer from neurologic complications like delirium. Also, the capacity to heal and regenerate tissue after surgery decreases with age, and can impact the quality of fracture repair and even osseous integration of implants. Thus, a better understanding of mechanisms that drive these age-dependent changes could provide strategic targets to minimize risk for such complications and optimize outcomes. Here, we introduce a clinically relevant mouse model of tibial fracture. The postoperative changes in these mice mimic some of the cognitive impairments commonly observed after routine orthopedic surgery in humans. Briefly, an incision is performed in the right hind limb under strictly aseptic conditions. Muscles are disassociated, and a 0.38-mm stainless steel pin is inserted into the upper crest of the tibia, inside the intramedullary canal. Osteotomy is then performed, and the wound is stapled. We have used this model to investigate the effects of surgical trauma on postoperative neuroinflammation and behavioral changes. By applying this fracture model in combination with parabiosis, a surgical model in which 2 mice are anastomosed, we have studied cells and secreted factors that systemically rejuvenate organ function and tissue regeneration after injury. By following our step-by-step protocol, these models can be reproduced with high fidelity, and can be adapted to interrogate many biologic pathways that are altered by surgical trauma.

This protocol describes a mouse model of orthopedic surgery that has been used to study mechanisms of postoperative neuroinflammation and behavioral changes, and when combined with parabiosis, to study tissue regeneration during aging.

骨科手术的小鼠模型研究术后认知功能障碍与组织再生

Surgery is commonly used to improve and maintain quality of life. Unfortunately, in vulnerable patients such as the elderly, complications may occur and ...

A Minimally Invasive Model to Analyze Endochondral Fracture Healing in Mice Under Standardized Biomechanical Conditions

Bone healing models are necessary to analyze the complex mechanisms of fracture healing to improve clinical fracture treatment. During the last decade, an increased use of mouse models in orthopedic research was noted, most probably because mouse models offer a large number of genetically-modified strains and special antibodies for the analysis of molecular mechanisms of fracture healing. To control the biomechanical conditions, well-characterized osteosynthesis techniques are mandatory, also in mice. Here, we report on the design and use of a closed bone healing model to stabilize femur fractures in mice. The intramedullary screw, made of medical-grade stainless steel, provides through fracture compression an axial and rotational stability compared to the mostly used simple intramedullary pins, which show a complete lack of axial and rotational stability. The stability achieved by the intramedullary screw allows the analysis of endochondral healing. A large amount of callus tissue, received after stabilization with the screw, offers ideal conditions to harvest tissue for biochemical and molecular analyses. A further advantage of the use of the screw is the fact that the screw can be inserted into the femur with a minimally invasive technique without inducing damage to the soft tissue. In conclusion, the screw is a unique implant that can ideally be used in closed fracture healing models offering standardized biomechanical conditions.

This protocol describes a minimally invasive osteosynthesis technique using an intramedullary screw for standardized stabilization of femur fractures, which can be used to analyze endochondral bone healing in mice.

标准化生物力学条件下小鼠软骨骨折愈合的微创模型分析

Bone healing models are necessary to analyze the complex mechanisms of fracture healing to improve clinical fracture treatment. During the last decade, an ...

The Generation of Closed Femoral Fractures in Mice: A Model to Study Bone Healing

Bone fractures impose a tremendous socio-economic burden on patients, in addition to significantly affecting their quality of life. Therapeutic strategies that promote efficient bone healing are non-existent and in high demand. Effective and reproducible animal models of fractures healing are needed to understand the complex biological processes associated with bone regeneration. Many animal models of fracture healing have been generated over the years; however, murine fracture models have recently emerged as powerful tools to study bone healing. A variety of open and closed models have been developed, but the closed femoral fracture model stands out as a simple method for generating rapid and reproducible results in a physiologically relevant manner. The goal of this surgical protocol is to generate unilateral closed femoral fractures in mice and facilitate a post-fracture stabilization of the femur by inserting an intramedullary steel rod. Although devices such as a nail or a screw offer greater axial and rotational stability, the use of an intramedullary rod provides a sufficient stabilization for consistent healing outcomes without producing new defects in the bone tissue or damaging nearby soft tissue. Radiographic imaging is used to monitor the progression of callus formation, bony union, and subsequent remodeling of the bony callus. Bone healing outcomes are typically associated with the strength of the healed bone and measured with torsional testing. Still, understanding the early cellular and molecular events associated with fracture repair is critical in the study of bone tissue regeneration. The closed femoral fracture model in mice with intramedullary fixation serves as an attractive platform to study bone fracture healing and evaluate therapeutic strategies to accelerate healing.

The murine closed femoral fracture model is a powerful platform to study fracture healing and novel therapeutic strategies to accelerate bone regeneration. The goal of this surgical protocol is to generate unilateral closed femoral fractures in mice using an intramedullary steel rod to stabilize the femur.

小鼠闭合性股骨骨折的形成: 骨愈合模型的研究

Bone fractures impose a tremendous socio-economic burden on patients, in addition to significantly affecting their quality of life. Therapeutic strategies ...

Protocol for Developing a Femur Osteotomy Model in Wistar Albino Rats

Fracture healing is a physiological process resulting in the regeneration of bone defects by the coordinated action of osteoblasts and osteoclasts. Osteoanabolic drugs have the potential to augment the repair of fractures but have constraints like high costs or undesirable side effects. The bone healing potential of a drug can initially be determined by in vitro studies, but in vivo studies are needed for the final proof of concept. Our objective was to develop a femur osteotomy rodent model that could help researchers understand the development of callus formation following fracture of the shaft of the femur and that could help establish whether a potential drug has bone healing properties. Adult male Wistar albino rats were used after Institutional Animal Ethics Committee clearance. The rodents were anesthetized, and under aseptic conditions, complete transverse fractures at the middle one-third of the shafts of the femurs were created using open osteotomy. The fractures were reduced and internally fixed using intramedullary K-wires, and secondary fracture healing was allowed to take place. After surgery, intraperitoneal analgesics and antibiotics were given for 5 days. Sequential weekly x-rays assessed callus formation. The rats were sacrificed based on radiologically pre-determined time points, and the development of the fracture callus was analyzed radiologically and using immunohistochemistry.

Here, we present a protocol to iatrogenically fracture the shaft of the femur of Wistar albino rats and follow up on the development of the callus. This femur osteotomy model can help researchers evaluate the process of fracture healing and to study how a drug could influence fracture healing.

开发Wistar白化大鼠股骨截骨模型的协议

Fracture healing is a physiological process resulting in the regeneration of bone defects by the coordinated action of osteoblasts and osteoclasts. ...

Transverse Fracture of the Mouse Femur with Stabilizing Pin

Fracture repair is an essential function of the skeleton that cannot be reliably modeled in vitro. A mouse injury model is an efficient approach to test whether a gene, gene product or drug influences bone repair because murine bones recapitulate the stages observed during human fracture healing. When a mouse or human breaks a bone, an inflammatory response is initiated, and the periosteum, a stem cell niche surrounding the bone itself, is activated and expands. Cells residing in the periosteum then differentiate to form a vascularized soft callus. The transition from the soft callus to a hard callus occurs as the recruited skeletal progenitor cells differentiate into mineralizing cells, and the bridging of the fractured ends results in the bone union. The mineralized callus then undergoes remodeling to restore the original shape and structure of the healed bone. Fracture healing has been studied in mice using various injury models. Still, the best way to recapitulate this entire biological process is to break through the cross-section of a long bone that encompasses both cortices. This protocol describes how a stabilized, transverse femur fracture can be safely performed to assess healing in adult mice. A surgical protocol including detailed harvesting and imaging techniques to characterize the different stages of fracture healing is also provided.

This protocol describes a method to perform fractures on adult mice and monitor the healing process.

带稳定针的小鼠股骨横断

Fracture repair is an essential function of the skeleton that cannot be reliably modeled in vitro. A mouse injury model is an efficient approach to test ...

生物学

Establishing a Diaphyseal Femur Fracture Model in Mice

Bones have a significant regenerative capacity. However, fracture healing is a complex process, and depending on the severity of the lesions and the age and overall health status of the patient, failures can occur, leading to delayed union or nonunion. Due to the increasing number of fractures resulting from high-energy trauma and aging, the development of innovative therapeutic strategies to improve bone repair based on the combination of skeletal/mesenchymal stem/stromal cells and biomimetic biomaterials is urgently needed. To this end, the use of reliable animal models is fundamental to better understanding the key cellular and molecular mechanisms that determine the healing outcomes. Of all the models, the mouse is the preferred research model because it offers a wide variety of transgenic strains and reagents for experimental analysis. However, the establishment of fractures in mice may be technically challenging due to their small size. Therefore, this article aims to demonstrate the procedures for the surgical establishment of a diaphyseal femur fracture in mice, which is stabilized with an intramedullary wire and resembles the most common bone repair process, through cartilaginous callus formation.

This protocol describes a surgical procedure for the establishment of a diaphyseal fracture in the femur of mice, which is stabilized with an intramedullary wire, for fracture healing studies.

建立小鼠骨干股骨骨折模型

Bones have a significant regenerative capacity. However, fracture healing is a complex process, and depending on the severity of the lesions and the age ...