ونحن نشكر الموظفين والأطباء البيطريين في وزارة سكوت ومستشفى الأبيض الطب المقارن، معبد بولاية تكساس، للحصول على المشورة التي لا تقدر بثمن والمساعدة خلال تطوير هذه التقنية. وقد تم تمويل هذا العمل في جزء من معهد الطب التجديدي أموال البرنامج، سكوت اند وايت RGP منحة # 90172، NIH 2P40RR017447-07 وNIH R01AR066033-01 (NIAMS). نشكر الدكتورة سوزان زيتوني لعزل المخطوطة.

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The authors have no competing financial interests.

هنا، نحن تصف طريقة بسيطة لتوليد عيب الحرجة الحجم استقرت دبوس من عظم الفخذ الفئران باستخدام المختبر القياسية والمعدات البيطرية. في حين أن التجمع من المسامير وإجراء العمليات الجراحية في حد ذاته يتطلب الممارسة، فإنه على ما يرام في حدود قدرات عالم أبحاث الطب الحيوي الم?...

ويقدر أن نصف سكان الولايات المتحدة يعاني من كسر في سن 65 1. بالنسبة لأولئك المرضى الذين يعانون من كسور المعالجة جراحيا، تشمل 500،000 إجراءات استخدام الكسب غير المشروع العظام 2 و من المتوقع أن يرتفع مع شيخوخة السكان على نحو متزايد 3 هذا العدد . على الرغم من أن العظام هي واحدة من عدد قليل من الأجهزة التي لديها القدرة على شفاء تماما بدون تندب، هناك حالات حيث فشل عملية 3،4. تبعا للظروف ونوعية العلاج، 2-30٪ من كسور العظام الطويلة تفشل، مما أدى إلى عدم النقابات 3،5. في حين لا يزال هناك بعض الجدل حول تعريف، فصال كاذب، وإصابات حرجة الحجم أو غير نقابية العظام تشير بصفة عامة إلى إصابة لا يلتئم على مدى عمر الطبيعي لهذا الموضوع (6). لأغراض تجريبية، هو تقصير هذه المدة إلى متوسط ​​الوقت اللازم للشفاء التام من متوسط ​​الحجم إصابة العظام. تحدث الآفات العظام غير نقابية لالأسطواناتأسباب erous، ولكن العوامل الرئيسية وتشمل الصدمة الشديدة مما أدى إلى وجود فجوة خطيرة الحجم، والعدوى، وضعف الأوعية الدموية، واستخدام التبغ، أو قدرة osteoregenerative تحول دون ذلك بسبب المرض أو العمر 7. حتى لو يتم التعامل غير النقابات بنجاح، فإنه يمكن أن تكلف ما يزيد على 60،000 دولار في الإجراء، وهذا يتوقف على نوع الإصابة والمناهج المستخدمة 8. وفي الحالات المعتدلة، وتوظيف ذاتي ترقيع العظام. وتتضمن هذه الاستراتيجية استرداد العظام من موقع المانحة وغرس في موقع الإصابة. في حين أن هذا النهج هو فعالة للغاية، وحجم متاح العظام المستمدة المانحة محدود وينطوي على إجراء عملية جراحية إضافية، مما يؤدي إلى ألم مستمر في العديد من المرضى 9،10. وبالإضافة إلى ذلك، فإن فعالية من الكسب غير المشروع العظام ذاتي يعتمد على صحة المريض. هي بدائل العظام مصنوعة من مواد تركيبية أو معالجتها العظام جثي متوافرة بكثرة 11-13، لكنها هكتارلقد قيود كبيرة، بما في ذلك سوء خصائص التصاق الخلية المضيفة، وانخفاض osteoconductivity، وإمكانية الرفض المناعي 14. ولذلك هناك حاجة ملحة لتقنيات تجديد العظام التي هي آمنة وفعالة ومتاحة على نطاق واسع. لدينا القدرة على تحسين استراتيجيات التجدد العظام تعتمد بشكل كبير على القدرة على تقليد الصدمة العظام خطيرة في حيوانات التجارب، ولكن الجيل واستقرار الآفات العظام كبيرة يمثل تحديا تقنيا. في معظم الحالات، يتم تحاكي صدمة خطيرة العظام الطويلة تجريبيا من خلال إنشاء الخلل التي لن تلتئم بشكل طبيعي. على الرغم من أنه يمكن أن تختلف مع الأنواع 15، ويتحقق ذلك عن طريق الإزالة الكاملة للشريحة العظام أكبر من 1.5 مرة من قطر العظام المقطع العرضي 16. ثم يستقر العظام مع زرع المعادن للحفاظ على التوجه السليم من حواف كسر والسماح للتنقل. نظرا لصغر حجمها وهشاشةالعظام الطويلة، وإنشاء مثل هذه الآفات في الفئران هم أبعد من قدرات معظم المجموعات البحثية. على هذا النحو، تقتصر نماذج عيب العظام الطويلة للفئران والحيوانات الكبيرة. ومع ذلك، والفئران تحمل مزايا البحثية الهامة في أنها يمكن المعدلة وراثيا وتربيتها كما سلالات خطر المناعية التي لا نرفض الخلايا البشرية والأنسجة. لالتطبيقات المستندة إلى خلية الإنسان والفئران خطر المناعية جذابة للعمل مع لأنها من الناحية الفسيولوجية تتميز بشكل جيد، وسهلة المنزل، وفعالة من حيث التكلفة، وسهولة تحليلها شعاعيا وتشريحيا. من الأهمية بمكان أن الفئران خطر المناعية لا يرفض الخلايا من مختلف الأنواع بما في ذلك البشر. يسمح صغر حجمها أيضا اختبار أعداد صغيرة جدا من الخلايا أو مجلدات من السقالات التجريبية في تطبيقات العظام. تم الإبلاغ عن عدة نماذج تقويم العظام الفئران التي تحمل درجات مختلفة من الاستقرار العظام 17،18. تلك التنفسيمللي التي تؤدي إلى مستويات عالية جدا من الاستقرار، مثل المثبتات الخارجية وتأمين لوحات تلتئم في الغالب من قبل التحجر داخل الغشاء على الرغم من أن الشفاء غضروفي وقد تم الإبلاغ عن 19. في المقابل، تلك التي تسمح بعض المتناهية الصغر و / أو الحركة الماكرو، مثل تلك التي تستخدم المسامير النخاعية غير المثبتة أو جزئيا ثابتة، وشفاء بشكل عام مع غلبة التحجر غضروفي 20،21. اتحاد تأخر أو عيوب غير نقابية من العظام الطويلة من الصعب بشكل خاص لتحقيق في الفئران بسبب مستوى إضافي من الاستقرار المطلوب. ومع ذلك، فقد تم الإبلاغ عن عدد من النهج، بما في ذلك دبابيس النخاعية مع المسامير المتشابكة، وتأمين لوحات والمثبتات الخارجية 22. هذه الأنظمة تعمل بشكل جيد عموما، ولكن نظرا تصميم معقد من أنها يمكن أن يكون تحديا تقنيا لتثبيت. على سبيل المثال، جارسيا وآخرون. 23 وضعت على المتشابكة نظام دبوس أنيق للاستخدام في الفئران، ولكن ينطوي على إجراء شقوق في اثنين الموقع مستقلالصورة وتعديل واسع من عظم الفخذ لاستيعاب الدبابيس. وأجريت هذه الإجراءات تحت المجهر تشريح. هنا، نحن تصف دبوس النخاع الفخذ بسيط مع طوق المركزي تهدف إلى منع إغلاق عجز العظم 3 مم وكذلك ترسيم حواف الأصلية للعيب. في حين دبوس لم يحدد حتى العظم نفسه، وتحجيم دقيق لقطر دبوس والتوسيع من نتائج تجويف النخاع في التدخل كافية للحد من الحركة الالتوائية (الشكل 1). مع اختيار دقيق من العمر الفطرية ونوع الجنس والفئران المتطابقة سلالة، والنتيجة هي تكرار للغاية التصنع غير uniondefect-22 التي يمكن تقييمها بسهولة شعاعيا. وعلاوة على ذلك المناطق ذات الاهتمام يمكن تعريف بتكاثر بعد التصوير المقطعي-حسابها الصغرى (μCT) لقياس دي نوفو تكوين العظام والمعلمات histomorphological. تم نموذج أولي من المسامير في مختبرنا باستخدام أدوات متوفرة بسهولة.<img alt="الشكل (1)" src="/files/ftp_upload/52368/52368fig1highres.jpg" /> الشكل 1: مبدأ التجريبي ملخص بياني للنموذج الخلل القطعي. يتم استئصاله وسط شريحة 3 ملم من 9-10 ملم عظم الفخذ الفئران جراحيا (يسار). يتم تمرير 3 مم طويل، 19 مقياس أنابيب الصلب الجراحية أكثر من 9 ملم طويلة، 22 G أنبوب الفولاذ المقاوم للصدأ وثابتة بمادة لاصقة في وسط الدقيق (يمين). تم تجهيز دبوس الناتجة في القنوات النخاعية ما تبقى من أجزاء القريبة والبعيدة للعظم الفخذ مع G طوق 19 استبدال جزء 3 ملم من العظم (أدناه، وسط).

<table><tbody><tr><td colspan="4">&lt;strong&gt;Pin assembly&lt;/strong&gt;</td></tr><tr><td>Dremel rotary tool</td><td>Dremel</td><td>8220</td><td>or equivalent</td></tr><tr><td>Heavy duty cut off wheel</td><td>Dremel</td><td>420</td><td></td></tr><tr><td>Surgical tubing 19&amp;nbsp;G</td><td>Small Parts (Amazon)</td><td>B000FMZ8LY</td><td>OD 1.07&amp;nbsp;mm, ID 0.889&amp;nbsp;mm</td></tr><tr><td>Surgical tubing 21&amp;nbsp;G</td><td>Small Parts (Amazon)</td><td>B000FMZ8YQ</td><td>OD 0.82&amp;nbsp;mm, ID 0.635&amp;nbsp;mm</td></tr><tr><td>Surgical tubing 22&amp;nbsp;G</td><td>Small Parts (Amazon)</td><td>B000FMYLZS</td><td>OD 0.719&amp;nbsp;mm, ID 0.502&amp;nbsp;mm</td></tr><tr><td>Surgical tubing 23&amp;nbsp;G</td><td>Small Parts (Amazon)</td><td>B000FN0SY0</td><td>OD 0.643&amp;nbsp;mm, ID 0.444&amp;nbsp;mm</td></tr><tr><td>Cyanoacrylate adhesive</td><td>Loctite</td><td>1365882</td><td></td></tr><tr><td>Emery disc</td><td>Dremel</td><td>413</td><td></td></tr><tr><td>Rubber polishing point</td><td>Dremel</td><td>462</td><td></td></tr><tr><td>Felt polishing disc</td><td>Dremel</td><td>414</td><td></td></tr><tr><td>Gelatin sponge</td><td>Surgifoam/Ethicon</td><td>1974</td><td></td></tr><tr><td>Punch biopsy cutter</td><td>Miltex</td><td>33-34</td><td></td></tr><tr><td colspan="4">&lt;strong&gt;Surgery/post-operative&lt;/strong&gt;</td></tr><tr><td>Warm pad and circulator pump</td><td>Stryker/Thermocare</td><td>TP700, TP700C, TPP722</td><td></td></tr><tr><td>Coverage quaternary spray</td><td>Steris</td><td>1429-77</td><td></td></tr><tr><td>Bead sterilizer</td><td>Germinator/CellPoint Scentific</td><td>Germinator 500</td><td></td></tr><tr><td>Anesthesia system</td><td>VetEquip Inc</td><td>901806 or 901807/901809</td><td></td></tr><tr><td>Isofluorane anesthetic</td><td>VETone/MWI</td><td>501017, 502017</td><td></td></tr><tr><td>Surgical disinfectant</td><td>Chloraprep/CareFusion</td><td>260449</td><td></td></tr><tr><td>Surgical tools</td><td>Fine Science Tools</td><td>various</td><td>recommend German made</td></tr><tr><td>Face protection</td><td>Splash Shield</td><td>4505</td><td></td></tr><tr><td>Rechargable high speed drill</td><td>Fine Science Tools</td><td>18000-17</td><td></td></tr><tr><td>Diamond cutting wheel</td><td>Strauss Diaiond</td><td>361.514.080HP</td><td></td></tr><tr><td>Absorbable sutures&amp;nbsp;</td><td>Covidien</td><td>UM-213</td><td></td></tr><tr><td>Outer sutures</td><td>Ethicon</td><td>668G</td><td>or equivalent</td></tr><tr><td>Vetbond</td><td>3M</td><td>1469SB</td><td>or equivalent</td></tr><tr><td>Hydration gel</td><td>Clear H2O</td><td>70-01-1082</td><td></td></tr><tr><td>Diet gel</td><td>Clear H2O</td><td>72-01-1062</td><td></td></tr><tr><td>Buprenorphine</td><td>Reckitt and Benckser</td><td>12496-0757-01</td><td>controlled substance</td></tr><tr><td>Mouse igloos</td><td>Bio Serv</td><td>K3328, 3570,3327</td><td></td></tr><tr><td>Euthanasia cocktail</td><td>Euthasol/Virbac</td><td>710101</td><td>controlled substance</td></tr><tr><td colspan="4">&lt;strong&gt;Analysis&lt;/strong&gt;</td></tr><tr><td>Live animal imager&amp;nbsp;</td><td>Orthoscan</td><td>FD Pulse</td><td>or equivalent</td></tr><tr><td>Micro-CT unit and software</td><td>Bruker</td><td>Skyscan1174</td><td>or equivalent</td></tr><tr><td>Sealing film/Parafilm M</td><td>VWR or Fisher</td><td>100501-338, S37441</td><td></td></tr><tr><td colspan="4">*Generic sources are suitable for all other items such as gause, drapes, protective clothing, animal care equipment.</td></tr></tbody></table>

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.

الفئران عادة استرداد وعيه والقائمة الخلفية التنقل 5-10 دقائق بعد انسحاب التخدير. خلال 5 أيام الأولى، فمن المستحسن لإيواء الفئران بشكل فردي وإدخال تخصيب البيئي لمنع استخدام الفائض من أطرافهم. لهذا الغرض، القباني من نوع أعشاش تقلل من الحاجة لبناء العش وتشجع يستريح. وقد ?...

Watch this Scientific Journal Video about A Simple Critical-sized Femoral Defect Model in Mice at JoVE.com

A Simple Critical-sized Femoral Defect Model in Mice

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.

بسيطة الحرجة الحجم فخذي عيب النموذجي في الفئران

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 ...

a-simple-critical-sized-femoral-defect-model-in-mice

Research

JoVE Journal

Medicine

15.1K Views.  Texas A&M Health Science Center. 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. 

Video: A Simple Critical-sized Femoral Defect Model in Mice

Use of Human Perivascular Stem Cells for Bone Regeneration

Human perivascular stem cells (PSCs) can be isolated in sufficient numbers from multiple tissues for purposes of skeletal tissue engineering1-3. PSCs are a FACS-sorted population of 'pericytes' (CD146+CD34-CD45-) and 'adventitial cells' (CD146-CD34+CD45-), each of which we have previously reported to have properties of mesenchymal stem cells. PSCs, like MSCs, are able to undergo osteogenic differentiation, as well as secrete pro-osteogenic cytokines1,2. In the present protocol, we demonstrate the osteogenicity of PSCs in several animal models including a muscle pouch implantation in SCID (severe combined immunodeficient) mice, a SCID mouse calvarial defect and a femoral segmental defect (FSD) in athymic rats. The thigh muscle pouch model is used to assess ectopic bone formation. Calvarial defects are centered on the parietal bone and are standardly 4 mm in diameter (critically sized)8. FSDs are bicortical and are stabilized with a polyethylene bar and K-wires4. The FSD described is also a critical size defect, which does not significantly heal on its own4. In contrast, if stem cells or growth factors are added to the defect site, significant bone regeneration can be appreciated. The overall goal of PSC xenografting is to demonstrate the osteogenic capability of this cell type in both ectopic and orthotopic bone regeneration models.

Human perivascular stem cells (PSCs) are a novel stem cell class for skeletal tissue regeneration similar to mesenchymal stem cells (MSCs). PSCs can be isolated by FACS (fluorescence activated cell sorting) from adipose tissue procured during standard liposuction procedures, then combined with an osteoinductive scaffold to achieve bone formation in vivo.

استخدام الخلايا الجذعية البشرية ارتشاح لتجديد العظام

Human perivascular stem cells (PSCs) can be isolated in sufficient numbers from multiple tissues for purposes of skeletal tissue engineering1-3. PSCs are ...

Bioengineering

A Simple Guide Screw Method for Intracranial Xenograft Studies in Mice

The grafting of human tumor cells into the brain of immunosuppressed mice is an established method for the study of brain cancers including glioblastoma (glioma) and medulloblastoma. The widely used stereotactic approach only allows for the injection of a single animal at a time, is labor intensive and requires highly specialized equipment. The guide screw method, initially developed by Lal et al.,1 was developed to eliminate cumbersome stereotactic procedures. We now describe a modified guide screw approach that is rapid and exceptionally safe; both of which are critical ethical considerations. Notably, our procedure now incorporates an infusion pump that allows up to 10 animals to be simultaneously injected with tumor cells.
To demonstrate the utility of this procedure, we established human U87MG glioma cells as intracranial xenografts in mice, which were then treated with AMG102; a fully human antibody directed to HGF/scatter factor currently undergoing clinical evaluation2-5. Systemic injection of AMG102 significantly prolonged the survival of all mice with intracranial U87MG xenografts and resulted in a number of complete cures. 
This study demonstrates that the guide screw method is an inexpensive, highly reproducible approach for establishing intracranial xenografts. Furthermore, it provides a relevant physiological model for validating novel therapeutic strategies for the treatment of brain cancers.

In order to evaluate novel therapeutic paradigms for the treatment of glioma, physiological relevant models are essential. We utilize an implantable guide screw procedure for establishment of intracranial xenograft models that is more rapid and safer than stereotactic approaches.

برغي دليل بسيط أسلوب للدراسات طعم أجنبي داخل الجمجمة في الفئران

The grafting of human tumor cells into the brain of immunosuppressed mice is an established method for the study of brain cancers including glioblastoma ...

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.

إنشاء القطاعي فخذي الحرجة حجم عيب النموذجي في الفئران استقرت بواسطة لوحة تثبيت طرفي العظم

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 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.

نموذج موثوق بها واستنساخه الحرجة الحجم القطاعي فخذي عيب في الفئران التي استقرت مع التبعي خارجية المخصصة

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

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.

نموذج مينيملي لتحليل الكسر Endochondral الشفاء في الفئران تحت ظروف النشاط الحيوي موحدة

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.

جيل كسور الفخذ مغلقة في الفئران: نموذج لدراسة شفاء العظام

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

إنشاء وتقييم صندوق الفخذ الفئران: نموذج عيب التجويف

Creating a Box-Cavity Defect Model in the Cortical Bone of Rat Femora

Severe bone defects or complex fractures can result in serious complications such as nonunion or insufficient bone healing. Tissue engineering, which involves the application of cells, scaffolds, and cytokines, is considered a promising solution for bone regeneration. Consequently, various animal models that simulate bone defects play a crucial role in exploring the therapeutic potential of tissue engineering for bone healing. In this study, we established a box-shaped cortical bone defect model in the mid-femur of rats, which could serve as an ideal model for assessing the function of biomaterials in promoting bone healing. This box-shaped cortical bone defect was drilled using an oral low-speed handpiece and shaped by a lathe needle. Post-operative micro-CT analysis was immediately conducted to confirm the successful establishment of the box-cavity cortical bone defect. The femurs on the operated side of the rats were then harvested at multiple time points post-surgery (0 days, 2 weeks, 4 weeks, and 6 weeks). The healing process of each sample&#39;s defect area was evaluated using micro-CT, hematoxylin and eosin (H&#38;E) staining, and Masson trichrome staining. These results demonstrated a healing pattern consistent with intramembranous ossification, with healing essentially complete by 6 weeks. The categorization of this animal model&#39;s healing process provides an effective in vivo method for investigating novel biomaterials and drugs that target intramembranous ossification during bone tissue defect healing.

تسليط الضوء على المؤلف: النهج القشري ذو التجويف الصندوقي لتعزيز تقييم المواد الحيوية وتجديد العظام

Here, we present a protocol for creating a box-cavity defect in rat femoral diaphysis tissue. This model can assess biomaterial performance under biomechanical stress and explore mechanisms of bone regeneration related to intramembranous osteogenesis.

إنشاء نموذج عيب تجويف صندوقي في العظم القشري لفأر الفخذ

Severe bone defects or complex fractures can result in serious complications such as nonunion or insufficient bone healing. Tissue engineering, which ...

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.

كسر عرضي لعظم عظم الفخذ مع دبوس التثبيت

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 ...

بسيطة الحرجة الحجم فخذي عيب النموذجي في الفئران

Summary

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Chapters in this video

استخدام الخلايا الجذعية البشرية ارتشاح لتجديد العظام

برغي دليل بسيط أسلوب للدراسات طعم أجنبي داخل الجمجمة في الفئران

إنشاء القطاعي فخذي الحرجة حجم عيب النموذجي في الفئران استقرت بواسطة لوحة تثبيت طرفي العظم

نموذج موثوق بها واستنساخه الحرجة الحجم القطاعي فخذي عيب في الفئران التي استقرت مع التبعي خارجية المخصصة

نموذج مينيملي لتحليل الكسر Endochondral الشفاء في الفئران تحت ظروف النشاط الحيوي موحدة

جيل كسور الفخذ مغلقة في الفئران: نموذج لدراسة شفاء العظام

إنشاء نموذج عيب تجويف صندوقي في العظم القشري لفأر الفخذ

إنشاء نموذج عيب تجويف صندوقي في العظم القشري لفأر الفخذ

إنشاء نموذج عيب تجويف صندوقي في العظم القشري لفأر الفخذ

كسر عرضي لعظم عظم الفخذ مع دبوس التثبيت