We thank members of the Mariani lab for critical reading of the manuscript. Our funding sources were: the Baxter Medical Scholar Research Fellowship (to M.K.S.), USC undergraduate fellowships and the Provost, Dean Joan M. Schaeffer, and Rose Hills Fellowships, (to M.K.S.). We also acknowledge a CIRM BRIDGES fellowship through Pasadena City College (to T.T.T). and the James H. Zumberge Research and Innovation Fund, the USC Regenerative Medicine Initiative, and the NIAMS NIH under Award Number R21AR064462 (to F.V.M).

注:所有的程序都是按照批准的机构动物护理和使用委员会（IACUC）在南加州大学的动物协议。 1.准备手术<ol><li>奠定了必要的外科手术工具和用品（消毒，项目1 - 18 材料清单），并安排一个解剖显微镜和光纤反式照明在引擎盖上或下沉气流表格。 </li><li>将一个性成熟的小鼠（20 - 30克，1 - 3个月）的感应室4％异氟醚诱导麻醉。 </li><li>确认麻醉用爪子和/或尾掐测试。 </li><li>适用软膏鼠标的眼睛，以避免手术过程中眼睛干涩。 </li><li>将鼠标移动到显微镜阶段。将鼠标进入检修软管的鼻锥和横向定位。提供邻近于动物的暖袋，以帮助维持体温。 不E:鼠标的位置是依赖于个人的喜好和/或外科医生的霸道，无论是左边或右边是好的。 </li><li>调整异氟醚为2 - 3％的维修，看呼吸频率。 </li><li>注入丁丙诺啡（0.05毫克/千克）经皮下（横向腿的侧翼），用于手术后疼痛与地下25针。腿可以抽搐这是一种正常的反应。 </li></ol> 2.切口开幕<ol><li>检测所需肋通过触诊，并清除了剃须刀的头发的区域。 注:肋8-10被推荐，因为肋1-7更接近肺和11-13都相当短。计数肋骨应该开始用最喙肋骨为1号。 </li><li>制备具有交替的聚维酮碘和异丙醇（70％）擦拭（3×常被推荐由动物使用的协议）的区域。 </li><li>通过皮肤切成2厘米的切口，正上方，并平行于与中型显微剪刀所需的肋。 Inc这是E到下面的肌肉和脂肪层。 </li><li>将所有3层（皮肤，肌肉，脂肪）到牵开器，以暴露手术区，同时最小切口的大小。 </li></ol> 3.切除肋骨<ol><li>通过肋间肌覆盖肋的所需部分与5.0毫米手术刀切割。位置周围5毫米近侧此切口的chondrocostal接头，这是其中的肋并不像高度弯曲。从小心地用细尖镊子骨分离肌肉。 </li><li>创建一个切除，同时保留在动物的骨膜，切断通过骨膜，沿肋的带5.0毫米手术刀的长度。仔细分离的骨膜从底层骨横向用细尖镊子。操作时要小心，因为骨膜十分细腻并有着一种凝胶状的一致性。 </li><li>在下使横截面穿过骨在一端与细微型剪刀。如果需要的话，测量切除掩模版在显微镜或直尺型测量仪。然后小心地将骨出骨膜和切断的另一端。 注:请谨慎操作。这是最微妙的一步，因为拉起不低于切除肋骨撕裂胸膜，造成气胸。如果胸膜膜被撕裂，这将是容易地明显的，因为胸腔的内部将变得可见。 </li><li>如果出血发生切割骨的结果，将压力施加于切割端用棉签4 - 5秒来止血。 注:在罕见场合继续出血，这可能是必要的，以停止和安乐死的动物作为显著失血会危及恢复（无补液，最大血液量可以安全地丢失是总血液体积的10％或7.7 - 8微升/克对于25克鼠标，这相当于约180 - 200微升9）。 </li><li>立即将取出的肋骨成4％PFA供日后分析。 注意:如果切除两个骨和骨膜的是要进行，省略了骨膜切口和分离（ 步骤3.2）。由于骨膜​​非常紧密附着于胸膜谨慎行事，挑逗肋远离胸膜用钳子以避免撕裂。 </li></ol> 4.关闭切口<ol><li>缝合肋间肌在剩余骨膜套筒用9-0缝合线（2缝线通常足够了）的顶部。放置缝线的肋的切断端部的正上方，作为指标，对手术位置。 </li><li>取出牵开。缝合覆肌肉和脂肪用9-0缝线（3 - 4缝线通常就足够了）。小鼠肌肉和/或脂 ​​肪的特别厚的层，分别缝合各层（ 例如，1层的缝合线的肌肉层和1层缝线的脂肪层）。 </li><li>关闭皮肤缝合7-0（4 - 5缝线通常就足够了）。 </li><li>确保切口缝合胶水，用大钳子捏边在一起。 </li><li>慢慢地戒掉鼠标关闭异氟醚，首先需要调节至1％的几分钟，然后熄灭。 </li><li>将鼠标下加热灯，并离开，直到意识恢复，5 - 10分钟。后意识恢复，并在整个愈合期，鼠标应该移动和走动正常并显示苦恼的迹象。 </li></ol> 5.恢复和分析<ol><li>提供术后疼痛管理，包括丁丙诺啡在0.5毫克口服明胶的形式管理/ kg，每12小时48小时。口服给药不需要抑制这可能会导致疼痛的胸部区域的动物。 </li><li>保持鼠标与在愈合期间自由获取食物和水的笼子里。后切口是干的，雌性动物可以共同收纳而男性s必须保持隔离，以防止战斗。 </li><li>愈合期后，按照批准的程序进行安乐死。拆下肋骨用于固定和分析。 </li></ol>

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The authors have nothing to disclose

当第一次学习此协议，确定在哪里可以找到最初的切口可以是具有挑战性。然而，在小鼠安乐死的做法可以帮助外科医生学会在哪里放置初始切口，暴露所需的肋骨被切除。工作在尸体也提高到具有或不具有骨膜除去肋部分所需的精细运动技能。此外，新的人到该过程可能会发现操纵细的工具和薄缝线是困难的。而打结，多余的拉动缝线可以撕裂组织。因此，一些实践缝合也对尸体可能是有帮助?...

衰弱的骨骼损伤，慢性骨关节炎，以及与重建手术相关的严重问题影响经济生产力，家庭幸福，和生活质量。而小断裂和损伤可以治愈还算不错，人类是不能修复大的缺陷，因此必须依靠重建手术，恢复的结构和功能。重建可能涉及同种异体或heterogeneic移植，骨morcellized，植入支架，或牵张成骨。不幸的是，不仅有与这些处理，但在修复骨骼的原始强度是很少获得持久性相关的发病率的因素。因此，需要新的临床方法。 单向开发创新的方法来治疗节段性缺损的研究中，大型维修时，自然的情况。著名的两栖动物可以再生骨骼元素，而哺乳动物被认为是有限的日是能力。然而，由于20 世纪初期，再生在人肋几个报告已经发表表明人类可能不被如此限制1-4。目前这种现象，最好由整形外科医生谁使用肋材料颚，脸和耳重建已知的，但它不是更广泛地理解5。为了研究这种修复中更详细地说，我们已经开发出使用鼠标的外科模型。使用该协议，研究人员可以识别所涉及的先天因素，并使用该信息，以便在其它地点的骨骼的愈合。 有许多优势，使用肋骨作为模型来研究骨骼修复。首先，将周围的肋提供自然固定器（相对于切除股骨6,7）。这降低了内部和外部固定器的发病风险并简化了外科手术。胸部西澳其次，薄肌层会提供易于访问和良好的能见度使得检测媲美颅骨切除8的便利。第三，在对比其通过膜内骨化，由软骨内骨化肋形式形成，并通过延伸在位于中央骨干的任一端生长板生长长度的颅骨。因此，修复肋可能更媲美修复长骨的阑尾骨架组成。此外，我们已经发现，相对于股骨，肋的骨膜较厚，可以更容易地操纵。因此，调查谁愿意测定骨修复的研究骨膜或测试细胞疗法，药物制剂，和/或组织支架的目的，可能会发现这种手术模式非常有用。总之，这个肋切除模型提供在其内来研究天然大型骨修复哺乳动物中一般使用没有这样的模型当前存在的上下文。

<table><tbody><tr><td>Medium sized micro-dissection scissors (Vannas-T&amp;uuml;bingen Spring Scissors 5 mm)</td><td>Fine Science Tools</td><td>15003-08</td><td></td></tr><tr><td>Fine micro-dissection scissors (Vannas Spring Scissors - 2mm Cutting Edge)</td><td>Fine Science Tools</td><td>15000-04</td><td>curved tip is beneficial</td></tr><tr><td>Micro-scalpel 5.0 mm</td><td>Fine Science Tools</td><td>10315-12</td><td>other fine scalpels can be substituted</td></tr><tr><td>Dumont 55 forceps</td><td>Fine Science Tools</td><td>11295-51</td><td></td></tr><tr><td>Retractor&amp;nbsp;</td><td>Fine Science Tools</td><td>17004-05</td><td>adjustability is convenient</td></tr><tr><td>Micro-needle holders</td><td>Fine Science Tools</td><td>12060-01</td><td></td></tr><tr><td>9.0 nylon sutures (Ethilon), taper point best</td><td>Ethicon</td><td>2819G or similar</td><td>taper point best but reverse cutting is also good</td></tr><tr><td>7.0 prolene sutures (Prolene)</td><td>Ethicon</td><td>8700H or similar</td><td>6-0 can be used too, needle point can vary</td></tr><tr><td>Large forceps (Adson Forceps)</td><td>Fine Science Tools</td><td>11006-12</td><td>other brands are fine</td></tr><tr><td>Lubricant Eye Ointment (Akwa Tears)</td><td>Akorn</td><td>17478-062-35</td><td></td></tr><tr><td>Suture glue (GLUture Topical Tissue Adhesive)</td><td>Abbot</td><td>32046-01</td><td>has excellent working time</td></tr><tr><td>Shaver</td><td>Wahl</td><td>9918-6171 or similar</td><td></td></tr><tr><td>Clamp lamp</td><td>Zoo Med</td><td>LF-5</td><td></td></tr><tr><td>Infrared Bulb, 75W</td><td>Zoo Med</td><td>RS-75</td><td></td></tr><tr><td>RC&lt;sup&gt;2&lt;/sup&gt; Rodent Anesthesia System</td><td>VetEquip&amp;nbsp;</td><td>922100</td><td></td></tr><tr><td>IsoFlo (Isoflurane)</td><td>Abbot</td><td>05260-05</td><td></td></tr><tr><td>Buprenorphine (Buprenex)</td><td>Reckitt Benckiser</td><td>12496-0757-1</td><td></td></tr><tr><td>Betadine</td><td>Purdue Frederick</td><td>67618015017</td><td></td></tr><tr><td>Flavored Gelatin, raspberry</td><td>Jell-O</td><td>B000E1FYL0</td><td>made up firm, to the consistency of &#039;jigglers&#039;</td></tr></tbody></table>

a surgical procedure for resecting the mouse rib: a model for large-scale long bone repair

该协议研究人员介绍，为大规模的骨修复利用鼠标肋骨的新模式。该过程详细描述了以下内容:准备动物进行手术的，打开胸体壁，从周围肋间肌曝光所需的肋，切除肋的所需部分，而不诱导气胸，并关闭所述切口。相较于四肢骨骼的骨头，肋骨都非常方便。此外，没有任何的内部或外部固定器是必要的，因为在相邻的肋提供自然的固定。手术采用市售的用品，很简单易学，且耐受性良好的动物。该过程可以进行具有或不具有除去周围骨膜，因此骨膜修复的贡献可以被评估。结果表明，如果被保留的骨膜，鲁棒修复发生在1 - 2个月。我们希望利用这个协议会鼓励研究到肋骨修复，而结果将有利于新的方式来刺激骨修复等身体周围地区的发展。

动物通常此过程中快速恢复，切口愈合良好，动物表现出正常的行为。该过程使用市售的用品和实践后，可在1小时内完成的。使用此过程来产生的实验数据前，有必要分析切除在第0天时间点，以确定是否有任何大的骨碎片可能会保留在切除区域内是重要的。评估适当的程序的一种方法是，以评估动物用X射线或显微成像术后，尽管这通常需要特别的辐射的安全认证。相反，另一种简单的评估可以?...

Watch this Scientific Journal Video about A Surgical Procedure for Resecting the Mouse Rib: A Model for Large-Scale Long Bone Repair at JoVE.com

A Surgical Procedure for Resecting the Mouse Rib: A Model for Large-Scale Long Bone Repair

The overall goal of this procedure is to successfully resect a portion of bone from the rib of a mouse. The procedure was developed as a model to study large-scale long bone repair.

外科手术切除为鼠标肋骨:模型进行大规模的长骨修复

This protocol introduces researchers to a new model for large-scale bone repair utilizing the mouse rib. The procedure details the following: preparation ...

a-surgical-procedure-for-resecting-mouse-rib-model-for-large-scale

Research

JoVE Journal

Medicine

13.0K 次观看.  Keck School of Medicine, University of Southern California. The overall goal of this procedure is to successfully resect a portion of bone from the rib of a mouse. The procedure was developed as a model to study large-scale long bone repair.

视频: A Surgical Procedure for Resecting the Mouse Rib: A Model for Large-Scale Long Bone Repair

A Mouse Distraction Osteogenesis Model

Distraction osteogenesis (DO) is a surgical procedure that involves skeletal tissue regeneration without cell transplantation. A DO model consists of the following three phases: the latency phase after osteotomy and placement of the external distractor; the distraction phase, wherein the separated bone ends are gradually and continuously distracted; and the consolidation phase. This custom-made distractor used for DO is comprised of two incomplete acrylic resin rings and an expansion screw. The process was initiated by making a mold with silicone impression material and then creating the custom-made distractor. Dental resin was poured into the formwork made of silicone impression material, and it was allowed to polymerize to create the incomplete resin rings required for the custom-made distractor. These rings were fixed with an expansion screw using transparent resin. The custom-made distractor created via this approach was attached to the tibia of mice. The tibia was fixed to the device using one pair of 25 G needles proximally, one pair of 27 G needles distally, and acrylic resin. After a latency period of 5 days, distraction was initiated at a rate of 0.2 mm/12 h. The lengthening was continued for 8 days, resulting in a total gap of 3.2 mm. The mice were sacrificed 4 weeks after distraction. Bone formation in the distraction gap was confirmed using both radiography and histology.

We present a mouse tibial distraction osteogenesis model developed using a custom-made distractor. The use of a mouse as an analysis target is advantageous for advancing research.

小鼠牵张成骨模型

Distraction osteogenesis (DO) is a surgical procedure that involves skeletal tissue regeneration without cell transplantation. A DO model consists of the ...

科研

发育生物学

Mouse Pneumonectomy Model of Compensatory Lung Growth

In humans, disrupted repair and remodeling of injured lung contributes to a host of acute and chronic lung disorders which may ultimately lead to disability or death. Injury-based animal models of lung repair and regeneration are limited by injury-specific responses making it difficult to differentiate changes related to the injury response and injury resolution from changes related to lung repair and lung regeneration. However, use of animal models to identify these repair and regeneration signaling pathways is critical to the development of new therapies aimed at improving pulmonary function following lung injury. The mouse pneumonectomy model utilizes compensatory lung growth to isolate those repair and regeneration signals in order to more clearly define mechanisms of alveolar re-septation. Here, we describe our technique for performing mouse pneumonectomy and sham pneumonectomy. This technique may be utilized in conjunction with lineage tracing or other transgenic mouse models to define molecular and cellular mechanism of lung repair and regeneration.

Mouse pneumonectomy is a commonly employed model of compensatory lung growth. This procedure can be used in conjunction with lineage tracing or transgenic mouse models to elucidate underlying mechanisms.

补偿性增长龙鼠标肺切除型号

In humans, disrupted repair and remodeling of injured lung contributes to a host of acute and chronic lung disorders which may ultimately lead to ...

医学

A Simple Critical-sized Femoral Defect Model in Mice

While bone has a remarkable capacity for regeneration, serious bone trauma often results in damage that does not properly heal. In fact, one tenth of all limb bone fractures fail to heal completely due to the extent of the trauma, disease, or age of the patient. Our ability to improve bone regenerative strategies is critically dependent on the ability to mimic serious bone trauma in test animals, but the generation and stabilization of large bone lesions is technically challenging. In most cases, serious long bone trauma is mimicked experimentally by establishing a defect that will not naturally heal. This is achieved by complete removal of a bone segment that is larger than 1.5 times the diameter of the bone cross-section. The bone is then stabilized with a metal implant to maintain proper orientation of the fracture edges and allow for mobility. 
Due to their small size and the fragility of their long bones, establishment of such lesions in mice are beyond the capabilities of most research groups. As such, long bone defect models are confined to rats and larger animals. Nevertheless, mice afford significant research advantages in that they can be genetically modified and bred as immune-compromised strains that do not reject human cells and tissue.
Herein, we demonstrate a technique that facilitates the generation of a segmental defect in mouse femora using standard laboratory and veterinary equipment. With practice, fabrication of the fixation device and surgical implantation is feasible for the majority of trained veterinarians and animal research personnel. Using example data, we also provide methodologies for the quantitative analysis of bone healing for the model.

Animal models are frequently employed to mimic serious bone injury in biomedical research. Due to their small size, establishment of stabilized bone lesions in mice are beyond the capabilities of most research groups. Herein, we describe a simple method for establishing and analyzing experimental femoral defects in mice.

一个简单的临界尺寸股骨缺损模型小鼠

While bone has a remarkable capacity for regeneration, serious bone trauma often results in damage that does not properly heal. In fact, one tenth of all ...

Establishment of a Segmental Femoral Critical-size Defect Model in Mice Stabilized by Plate Osteosynthesis

The use of tissue-engineered bone constructs is an appealing strategy to overcome drawbacks of autografts for the treatment of massive bone defects. As a model organism, the mouse has already been widely used in bone-related research. Large diaphyseal bone defect models in mice, however, are sparse and often use bone fixation which fills the bone marrow cavity and does not provide optimal mechanical stability. The objectives of the current study were to develop a critical-size, segmental, femoral defect in nude mice. A 3.5-mm mid-diaphyseal femoral ostectomy (approximately 25% of the femur length) was performed using a dedicated jig, and was stabilized with an anterior located locking plate and 4 locking screws. The bone defect was subsequently either left empty or filled with a bone substitute (syngenic bone graft or coralline scaffold). Bone healing was monitored noninvasively using radiography and in vivo micro-computed-tomography and was subsequently assessed by ex vivo micro-computed-tomography and undecalcified histology after animal sacrifice, 10 weeks postoperatively. The recovery of all mice was excellent, a full-weight-bearing was observed within one day following the surgical procedure. Furthermore, stable bone fixation and consistent fixation of the implanted materials were achieved in all animals tested throughout the study. When the bone defects were left empty, non-union was consistently obtained. In contrast, when the bone defects were filled with syngenic bone grafts, bone union was always observed. When the bone defects were filled with coralline scaffolds, newly-formed bone was observed in the interface between bone resection edges and the scaffold, as well as within a short distance within the scaffold. 
The present model describes a reproducible critical-size femoral defect stabilized by plate osteosynthesis with low morbidity in mice. The new load-bearing segmental bone defect model could be useful for studying the underlying mechanisms in bone regeneration pertinent to orthopaedic applications.

Although mouse models are invaluable tools for bone tissue engineering, models of long bone defects are sparse. This need motivated development of the present protocol which uses a locking plate with four screws and a dedicated jig to perform and stabilize a reproducible, femoral, critical-size defect with low morbidity.

在小鼠节段性股临界尺寸缺陷模型的建立接骨板稳定

The use of tissue-engineered bone constructs is an appealing strategy to overcome drawbacks of autografts for the treatment of massive bone defects. As a ...

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 ...

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 ...

缝合扩张小鼠拉伸载荷下骨重塑的 3D 可视化

A 3-D Visualization Technique for Bone Remodeling in a Suture Expansion Mouse Model

Craniofacial sutures play a crucial role beyond being fibrous joints connecting craniofacial bones; they also serve as the primary niche for calvarial and facial bone growth, housing mesenchymal stem cells and osteoprogenitors. As most craniofacial bones develop through intramembranous ossification, the sutures' marginal regions act as initiation points. Due to this significance, these sutures have become intriguing targets in orthopedic therapies like spring-assisted cranial vault expansion, rapid maxillary expansion, and maxillary protraction. Under orthopedic tracing force, suture stem cells are rapidly activated, becoming a dynamic source for bone remodeling during expansion. Despite their importance, the physiological changes during bone remodeling periods remain poorly understood. Traditional sectioning methods, primarily in the sagittal direction, do not capture the comprehensive changes occurring throughout the entire suture. This study established a standard mouse model for sagittal suture expansion. To fully visualize bone remodeling changes post-suture expansion, the PEGASOS tissue clearing method was combined with whole-mount EdU staining and calcium chelating double labeling. This allowed the visualization of highly proliferating cells and new bone formation across the entire calvarial bones following expansion. This protocol offers a standardized suture expansion mouse model and a 3-D visualization method, shedding light on the mechanobiological changes in sutures and bone remodeling under tensile force loading.

作者聚焦:PEGASOS 组织透明化技术可视化骨骼重塑 

This protocol presents a standardized suture expansion mouse model and a 3-D visualization method to study the mechanobiological changes of the suture and bone remodeling under tensile force loading.

缝合扩张小鼠模型中骨重塑的 3D 可视化技术

Craniofacial sutures play a crucial role beyond being fibrous joints connecting craniofacial bones; they also serve as the primary niche for calvarial and ...