Name: protocol for developing a femur osteotomy model in wistar albino rats
Uploaded: 2022-08-31T12:30:00
Description: Watch this Scientific Journal Video about Protocol for Developing a Femur Osteotomy Model in Wistar Albino Rats at JoVE.com

The authors would like to thank Central Council for Research in Homoeopathy (CCRH), Ministry of AYUSH, Govt. of India, for research funding. The authors are grateful for the help and support of Central Animal Facility, AIIMS, New Delhi, for their help and support with the animal experiments and CMET, AIIMS, New Delhi, for their help and support in photography and videography.

Animal experiments were done after taking ethical approval from the Institutional Animal Ethics Committee (IAEC), AIIMS, New Delhi, India (286/IAEC-1/2021).
1. Preoperative procedure
<ol>
	<li>House male Wistar albino rats 6-8 weeks of age, weighing between 150-200 g each, at a Central Animal Facility (CAF) in separate individual cages. This ensures no surgical/fracture site injury when multiple rats share cages.</li>
	<li>Keep the rats at a temperature of 23 &#176;C &#177; ...

<ol>
	<li>Wang, T., Zhang, X., Bikle, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteogenic+differentiation+of+periosteal+cells+during+fracture+healing.">Osteogenic differentiation of periosteal cells during fracture healing.</a> Journal of Cellular Physiology. 232 (5), 913-921 (2017).</li><li>Fakhry, M., Hamade, E., Badran, B., Buchet, R., Magne, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mechanisms+of+mesenchymal+stem+cell+differentiation+towards+osteoblasts.">Molecular mechanisms of mesenchymal stem cell differentiation towards osteoblasts.</a> World Journal of Stem Cells. 5 (4), 136-148 (2013).</li><li>Bishop, J. A., Palanca, A. A., Bellino, M. J., Lowenberg, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+compromised+fracture+healing.">Assessment of compromised fracture healing.</a> JAAOS - Journal of the American Academy of Orthopaedic Surgeons. 20 (5), 273-282 (2012).</li><li>Fong, 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=Predictors+of+nonunion+and+reoperation+in+patients+with+fractures+of+the+tibia:+an+observational+study.">Predictors of nonunion and reoperation in patients with fractures of the tibia: an observational study.</a> BMC Musculoskeletal Disorders. 14 (1), 103 (2013).</li><li>Ramoutar, D. N., Rodrigues, J., Quah, C., Boulton, C., Moran, C. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Judet+decortication+and+compression+plate+fixation+of+long+bone+nonunion:+Is+bone+graft+necessary.">Judet decortication and compression plate fixation of long bone nonunion: Is bone graft necessary.</a> Injury. 42 (12), 1430-1434 (2011).</li><li>Goulet, J. A., Senunas, L. E., DeSilva, G. L., Greenfield, M. L. V. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autogenous+iliac+crest+bone+graft:+Complications+and+functional+assessment.">Autogenous iliac crest bone graft: Complications and functional assessment.</a> Clinical Orthopaedics and Related Research. 339, 76-81 (1997).</li><li>Stevenson, 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=A+systematic+review+and+economic+evaluation+of+alendronate,+etidronate,+risedronate,+raloxifene+and+teriparatide+for+the+prevention+and+treatment+of+postmenopausal+osteoporosis.">A systematic review and economic evaluation of alendronate, etidronate, risedronate, raloxifene and teriparatide for the prevention and treatment of postmenopausal osteoporosis.</a> Health Technology Assessment. 9 (22), 1 (2005).</li><li>Haffner-Luntzer, M., Kovtun, A., Rapp, A. E., Ignatius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+in+bone+fracture+healing+research.">Mouse models in bone fracture healing research.</a> Current Molecular Biology Reports. 2 (2), 101-111 (2016).</li><li>Mills, L. A., Simpson, A. H. R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+models+of+bone+repair.">In vivo models of bone repair.</a> The Journal of Bone and Joint Surgery. British Volume. 94 (7), 865-874 (2012).</li><li>Houdebine, L. -. M., Sioud, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenic+Animal+Models+in+Biomedical+Research.">Transgenic Animal Models in Biomedical Research.</a> Target Discovery and Validation Reviews and Protocols: Volume 1, Emerging Strategies for Targets and Biomarker Discovery. , (2007).</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=Small+animal+bone+healing+models:+Standards,+tips+and+pitfalls+results+of+a+consensus+meeting.">Small animal bone healing models: Standards, tips and pitfalls results of a consensus meeting.</a> Bone. 49 (4), 591-599 (2011).</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>Klein, 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=Comparison+of+healing+process+in+open+osteotomy+model+and+open+fracture+model:+delayed+healing+of+osteotomies+after+intramedullary+screw+fixation.">Comparison of healing process in open osteotomy model and open fracture model: delayed healing of osteotomies after intramedullary screw fixation.</a> Journal of Orthopaedic Research. 33 (7), 971-978 (2015).</li><li>Kolios, 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=Do+estrogen+and+alendronate+improve+metaphyseal+fracture+healing+when+applied+as+osteoporosis+prophylaxis.">Do estrogen and alendronate improve metaphyseal fracture healing when applied as osteoporosis prophylaxis.</a> Calcified Tissue International. 86 (1), 23-32 (2010).</li><li>Holstein, J. H., 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=Advances+in+the+establishment+of+defined+mouse+models+for+the+study+of+fracture+healing+and+bone+regeneration.">Advances in the establishment of defined mouse models for the study of fracture healing and bone regeneration.</a> Journal of Orthopaedic Trauma. 23, 31-38 (2009).</li><li>Umiatin, U., Dilogo, I. H., Sari, P., Wijaya, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histological+analysis+of+bone+callus+in+delayed+union+model+fracture+healing+stimulated+with+pulsed+electromagnetic+fields+(PEMF).">Histological analysis of bone callus in delayed union model fracture healing stimulated with pulsed electromagnetic fields (PEMF).</a> Scientifica. 2021, 4791172 (2021).</li><li>Han, W., 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+osteogenic+potential+of+human+bone+callus.">The osteogenic potential of human bone callus.</a> Scientific Reports. 6, 36330 (2016).</li><li>Haffner-Luntzer, 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=A+novel+mouse+model+to+study+fracture+healing+of+the+proximal+femur.">A novel mouse model to study fracture healing of the proximal femur.</a> Journal of Orthopaedic Research. 38 (10), 2131-2138 (2020).</li><li>Aur&#233;gan, J. 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+rat+model+of+femur+fracture+for+bone+and+mineral+research:+An+improved+description+of+expected+comminution,+quantity+of+soft+callus+and+incidence+of+complications.">The rat model of femur fracture for bone and mineral research: An improved description of expected comminution, quantity of soft callus and incidence of complications.</a> Bone &amp; Joint Research. 2 (8), 149-154 (2013).</li><li>Li, Z., 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=Drill+hole+models+to+investigate+bone+repair.">Drill hole models to investigate bone repair.</a> Methods in Molecular Biology. 2221, 193-204 (2021).</li><li>Handool, K. O., 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=Optimization+of+a+closed+rat+tibial+fracture+model.">Optimization of a closed rat tibial fracture model.</a> Journal of Experimental Orthopaedics. 5 (1), 13 (2018).</li><li>Kobata, S. 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=Prevention+of+bone+infection+after+open+fracture+using+a+chitosan+with+ciprofloxacin+implant+in+animal+model.">Prevention of bone infection after open fracture using a chitosan with ciprofloxacin implant in animal model.</a> Acta Cirurgica Brasileira. 35 (8), 202000803 (2020).</li></ol>

This method lucidly describes the details needed to develop a fracture osteotomy model in Wistar albino rats. This model can be used to evaluate the osteogenic effect of a promising osteoanabolic drug in fracture healing, as well as understand the intricacies of bone healing. The salient feature of this method is that it is simple and does not need too much time or sophisticated equipment. In this method, adult male Wistar albino rats were selected as the rodent model for the experiments. Uniform gender was selected to r...

Bone is a dense connective tissue consisting of bone-forming cells, the osteoblasts, and bone-resorbing cells, the osteoclasts. Fracture healing is a physiological process resulting in the regeneration of bone defects by the coordinated action of osteoblasts and osteoclasts1. When there is a fracture, osteoblastic and osteoclastic activity at the fracture site are some of the important factors that determine bone healing2. When fracture healing deviates from its normal course, it results in a delayed union, malunion, or nonunion. A fracture is said to be in nonunion when there is a failure of union of the fracture for 9 months, with no progression of repair in the last 3 months3. Approximately 10%-15% of all fractures experience a delay in repair that may progress to nonunion4. The nonunion rate for all fractures is 5%-10% and varies depending on the bone involved and the site of fracture5.
The current regimen for the treatment of fracture nonunion comprises surgical and/or medical modalities. Currently, delayed or nonunion of fractures can be overcome by surgical strategies like bone grafting. However, bone grafting has its limitations and complications like availability of graft tissue, donor site pain, morbidity, and infection6. Medical treatment comprises osteoanabolic drugs like bone morphogenetic protein (BMP) and teriparatide (parathormone analog). Currently used osteoanabolic agents have the potential to augment the repair of fractures but have constraints like exorbitant costs or undesirable side effects7. Hence, there is scope for identifying cost-effective, nonsurgical alternatives for bone healing. 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. A drug that is known to enhance bone healing should be evaluated in vitro and, if found promising, can be used for in vivo animal model studies. If the drug proves to promote bone formation and remodeling in the in vivo model, it could proceed to the next stage (i.e., clinical trials).
Assessing fracture healing in animals is a logical step forward to evaluate a novel agent introduced for bone healing before it undergoes human trials. For in vivo animal model studies of fracture healing, rodents have become an increasingly popular model8. The rodent models have generated increasing interest due to the low operational costs, limited need for space, and less time needed for bone healing9. In addition, rodents have a broad spectrum of antibodies and gene targets, which allow studies on the molecular mechanisms of bone healing and regeneration10. A consensus meeting comprehensively highlighted various small animal bone healing models and focused on the different parameters influencing bone healing, as well as emphasizing several small animal fracture models and implants11.
Basic fracture models can be broadly divided into open or closed models. Closed fracture models use a three- or four-point bending force on the bone and do not require a conventional surgical approach. They lead to oblique or spiral fractures, resembling long bone fractures in humans, but the lack of standardization of fracture location and dimensions may act as a confounding factor in them12. Open fracture models require surgical access for osteotomy of the bone, help to achieve a more consistent fracture pattern at the fracture site, but are associated with delayed healing compared to the closed models13. The choice of bone used to study fracture healing mainly remains the tibia and femur due to their dimensions and accessibility. The choice of the site of fracture is usually the diaphysis or metaphysis. The metaphyseal region is specially chosen in cases where fracture healing is studied in osteoporotic subjects, as the metaphysis is more affected by osteoporosis14. Several implants like intramedullary pins and external fixators can be used to stabilize the fracture11,15.
The objective of this study was to develop a simple and easy-to-follow rodent model that could help researchers not only understand the development of the callus following fracture of the femur but could help to determine whether a potential drug has bone healing properties by understanding the mechanism by which it acts.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Alcohol</td>
			<td>Raman &#38; Weil Pvt. Ltd, Mumbai, Maharashtra, India</td>
			<td>MFG/MD/2019/000189</td>
			<td>Sterillium hand disinfectant</td>
		</tr>
		<tr>
			<td>Artery forceps&#160;</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>G.105.05S</td>
			<td>5&#34;, straight</td>
		</tr>
		<tr>
			<td>Bard-Parker handle&#160;</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>G.103.03</td>
			<td>Size number 3</td>
		</tr>
		<tr>
			<td>Betadine solution</td>
			<td>Win-medicare New Delhi, India</td>
			<td>UP14250000001</td>
			<td>10% w/v Povidone iodine solution</td>
		</tr>
		<tr>
			<td>Cat&#39;s-paw skin retractor&#160;</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>908.S</td>
			<td>Small</td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Sisco research laboratories Pvt. Ltd, Maharashtra, India</td>
			<td>43272</td>
			<td>Disodium salt</td>
		</tr>
		<tr>
			<td>Eosin</td>
			<td>Sigma Aldrich, Merck Life Sciences Pvt Ltd, Mumbai, Maharashtra, India</td>
			<td>115935</td>
			<td>For preparing the staining solution&#160;</td>
		</tr>
		<tr>
			<td>Forceps (plain)</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>115.06</td>
			<td>6&#34;, plain</td>
		</tr>
		<tr>
			<td>Forceps (toothed)</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>117.06</td>
			<td>6&#34;, toothed</td>
		</tr>
		<tr>
			<td>Formaldehyde</td>
			<td>Sisco research laboratories Pvt. Ltd, Maharashtra, India</td>
			<td>84439</td>
			<td>For preparing the neutral buffered formalin&#160;</td>
		</tr>
		<tr>
			<td>Haematoxylin</td>
			<td>Sigma Aldrich, Merck Life Sciences Pvt Ltd, Mumbai, Maharashtra, India</td>
			<td>104302</td>
			<td>For preparing the staining solution&#160;</td>
		</tr>
		<tr>
			<td>Hammer</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>401.M</td>
			<td></td>
		</tr>
		<tr>
			<td>Injection Cefuroxime</td>
			<td>Akumentis Healthcare Ltd, Thane, Maharashtra, India</td>
			<td>48/UA/SC/P-2013</td>
			<td>Cefuroxime sodium IP, 1.5 g/vial&#160;</td>
		</tr>
		<tr>
			<td>Injection Ketamine</td>
			<td>Baxter Pharmaceuticals India Private Limited, Gujarat, India</td>
			<td>G/28-B/6</td>
			<td>Ketamine hydrochloride IP, 50 mg/mL&#160;</td>
		</tr>
		<tr>
			<td>Injection Xylazine</td>
			<td>Indian Immunologicals Limited, Hyderabad, Telangana, India</td>
			<td>28/RR/AP/2009/F/G</td>
			<td>Xylazine hydrochloride USP, 20 mg/mL</td>
		</tr>
		<tr>
			<td>Injection Lignocaine</td>
			<td>Jackson laboratories Pvt Limited, Punjab, India&#160;</td>
			<td>1308-B</td>
			<td>2% Lignocaine Hydrochloride IP, 21.3 mg/mL</td>
		</tr>
		<tr>
			<td>Injection Tramadol&#160;</td>
			<td>Intas Pharmaceuticals Limited, Ahmedabad, Gujarat, India</td>
			<td>MB/07/500</td>
			<td>Tramadol hydrochloride IP, 50 mg/mL</td>
		</tr>
		<tr>
			<td>K-wire&#160;</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>166 (1mm)</td>
			<td>12&#34;, double ended</td>
		</tr>
		<tr>
			<td>Mechanical drill for inserting K-wire</td>
			<td>&#8206;Bosch, Germany&#160;</td>
			<td>06019F70K4</td>
			<td>GSR 120-LI Professional</td>
		</tr>
		<tr>
			<td>Metzenbaum cutting scissors&#160;</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>G.121.06S</td>
			<td>6&#34;, straight</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>G.108.06</td>
			<td>6&#34;, straight</td>
		</tr>
		<tr>
			<td>Ophthalmic ointment&#160;</td>
			<td>GlaxoSmithKline Pharmaceutical Limited, Bengaluru, Karnataka, India</td>
			<td>KTK/28a/467/2001</td>
			<td>Neomycin, Polymixin B sulfate and Bacitracin zinc ophthalmic ointment USP</td>
		</tr>
		<tr>
			<td>Osteotome (chisel)</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>1001.S.10</td>
			<td>10 mm, straight</td>
		</tr>
		<tr>
			<td>Periosteal elevator&#160;</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>918.10.S</td>
			<td>10 mm, straight</td>
		</tr>
		<tr>
			<td>Pliers cum wire cutter</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>604.65</td>
			<td></td>
		</tr>
		<tr>
			<td>Reynold&#8217;s scissors</td>
			<td>Nebula surgical, Gujarat, India</td>
			<td>G.110.06S</td>
			<td>6&#34;, straight</td>
		</tr>
		<tr>
			<td>Standard semi-synthetic diet&#160;</td>
			<td>Ashirvad Industries, Chandigarh, India</td>
			<td>No catalog number available</td>
			<td>Detailed composition provided in materials used</td>
		</tr>
		<tr>
			<td>Steel cup for keeping betadine for application</td>
			<td>Local purchase</td>
			<td>No catalog number available</td>
			<td></td>
		</tr>
		<tr>
			<td>Steel tray with lid for autoclaving instruments</td>
			<td>Local purchase</td>
			<td>No catalog number available</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile gauze</td>
			<td>Ideal Healthcare Industries, Delhi, India&#160;</td>
			<td>E(0047)/14/MNB/7951</td>
			<td>Sterile, 5cmx5cm, 12 ply</td>
		</tr>
		<tr>
			<td>Sterile marble block for support</td>
			<td>Local purchase</td>
			<td>No catalog number available</td>
			<td>Locally fabricated; autoclavable</td>
		</tr>
		<tr>
			<td>Syringe and needle (1 mL)&#160;</td>
			<td>Becton Dickinson India Pvt. Ltd., Haryana, India</td>
			<td>REF 303060</td>
			<td>1 mL sterile Syringe with 26 G x 1/2 (0.45 mm x 13 mm) needle</td>
		</tr>
		<tr>
			<td>Syringe and needle (2 mL)&#160;</td>
			<td>Becton Dickinson India Pvt. Ltd., Haryana, India</td>
			<td>REF 307749</td>
			<td>2 mL sterile syringe with 24 G x 1&#39;&#39; (0.55 mm x 25 mm) needle</td>
		</tr>
		<tr>
			<td>Syringe and needle (10 mL)&#160;</td>
			<td>Hindustan Syringes &#38; Medical Devices Ltd. Faridabad, India&#160;</td>
			<td>334-B(H)</td>
			<td>10 mL sterile syringe with 21 G x1.5&#34; (0.80 mm x 38 mm) needle</td>
		</tr>
		<tr>
			<td>Surgical blades (size no.15)</td>
			<td>Paramount Surgimed Ltd, New Delhi, India for Medline Industries Inc, IL, USA</td>
			<td>REF MDS15115E</td>
			<td>Sterile, Single use</td>
		</tr>
		<tr>
			<td>Surgical blades (size no.24)</td>
			<td>Paramount Surgimed Ltd, New Delhi, India for Medline Industries Inc, IL, USA</td>
			<td>REF MDS15124E</td>
			<td>Sterile, Single use</td>
		</tr>
		<tr>
			<td>Sutures</td>
			<td>Healthium Medtech Pvt Ltd, Bangalore, Karnataka, India</td>
			<td>SN 3318</td>
			<td>4-0, 16 mm, 3/8 circle cutting needle, monofilament polyamide suture&#160;</td>
		</tr>
		<tr>
			<td>Wax block in aluminium tray&#160;</td>
			<td>Locally fabricated</td>
			<td>No catalog number available</td>
			<td>30 cm x 30 cm x 4 cm aluminium tray containing wax (to prevent animal from slipping)</td>
		</tr>
		<tr>
			<td>X-ray machine</td>
			<td>Philips India Ltd, Gurugram, Haryana</td>
			<td>SN19861013</td>
			<td>Model: Philips Digital Diagnost R 4.2&#160;</td>
		</tr>
	</tbody>
</table>

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.

This study was undertaken to develop a femur osteotomy model in Wistar albino rats. This model can be used to evaluate bone healing, as well as the osteogenic effect of a promising osteoanabolic drug in bone healing. Standard surgical precautions and protocols were followed. Sterile gowns, drapes, and surgical equipment were used for the procedure (Figure 1). The equipment (Table 1) was sterilized 48 h before surgery. Anesthetic, analgesic, and antibiotics were used as per t...

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Protocol for Developing a Femur Osteotomy Model in Wistar Albino Rats

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.

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

This femur osteotomy model can help researchers study the process of fracture healing and evaluate how a drug could influence fracture healing. It is a simple and easy to follow rodent model that can help researchers identify if a drug has bone-healing properties and understand its mechanism of action. Even though it mainly focuses on observing and analyzing fracture healing, it can also give insights into disease pathogenesis.This method can guide future research on bone-healing in health and disease. It can be used to evaluate the effect of potential osteoanabolic drugs. Inducing a proper fracture line and fracture fixation with with a K-wire are challenging.A couple of practice sessions should help. The simplicity and reproducibility of this method are evident in its visual demonstration Pawan Pagaku, a junior resident from my laboratory, will help to demonstrate the procedure. To begin place the wax block containing wax up to a depth of 2.5 centimeters on the operating table and cover it with sterile drapes.After making a one centimeter vertical skin incision on the lateral side of the right thigh, expose the vastus lateralis muscle by separating the deep fascia using Metzenbaum scissors. Split the vastus lateralis in line with the muscle fibers until the shaft of the femur is reached. Then, use the periosteal elevator to free the bone from the muscles attached to it.After injecting local anesthesia in and around the periosteum, create an indentation in the middle third of the shaft of the femur using the number 15 surgical blade. Place a chisel on the indentation and gently tap the chisel with a hammer to completely fracture the bone in the middle third of the shaft. Internally fix the fracture using a one-millimeter sterile K-wire held with the help of a battery operated power drill.Pass the K-wire into the medullary canal of the distal fragment through the fracture site. Then, drill out the K-wire through the distal end of the femur. After reducing the fracture, advance the K-wire from the distal end into the canal of the proximal fragment until it obtains purchase in the trochanteric region.Cut off the distal part of the K-wire protruding through the skin using a wire cutter. Bend the tip of the K-wire to around 90 degrees using pliers and use a gauze bandage soaked in Betadine for pin site dressing. The K-wire acts as an intramedullary splint for keeping the fracture in a reduced position.Apply pressure on the bleeding area using sterile gauze or artery forceps to stop any bleeding. Ensure complete hemostasis before closing the skin using a 4-0 nylon suture. Clean the wound with Betadine and cover it with sterile gauze and micropore adhesive tape.For postoperative care, return the rats to their cages and continue giving a standard semi-synthetic diet as well as antibiotics and analgesics intraperitoneally for five days after the procedure. Finally, assess bone healing by X-ray of the fractured site once weekly. X-rays of the rat's femur with the K-wire NC2 before inducing the fracture, and one day after surgery are shown here.The fracture healing is monitored radiologically by taking sequential weekly X-rays of the operated site to assess callus formation. The fracture remains reduced and immobilized with the intramedullary K wire. After sacrifice at a predetermined time point, the femur was carefully preserved in formalin, followed by bone decalcification.Bone with callus was obtained after optimal decalcification. The intact callus, and sagittal section of the callus are shown here. The callus is intermittently assessed to ensure optimal decalcification before evaluating it using other techniques.Low magnification and high magnification images of the hematoxylin and eosin stained section of the fracture site are shown here. The stained sections of the fracture site show a hard callus with the formation of cartilage and new bone. The fractured end of the bone and the second cortical region can be seen here.The periosteum most pain-sensitive part of the wound, and it is essential to infiltrate the periosteum at the fracture site with a local anesthetic before the osteotomy. It can be followed by immunohistochemical and radiological analysis of the callous, micro-CT for quantitative histomorphometry, analyzing the biomechanical strength of the callus analyze of serum. This technique is useful to determine the osteogenic potential, mechanism of action, and comparative analysis of promising osteoanabolic drugs.

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Quantifying Glomerular Permeability of Fluorescent Macromolecules Using 2-Photon Microscopy in Munich Wistar Rats

Kidney diseases involving urinary loss of large essential macromolecules, such as serum albumin, have long been thought to be caused by alterations in the permeability barrier comprised of podocytes, vascular endothelial cells, and a basement membrane working in unison. Data from our laboratory using intravital 2-photon microscopy revealed a more permeable glomerular filtration barrier (GFB) than previously thought under physiologic conditions, with retrieval of filtered albumin occurring in an early subset of cells called proximal tubule cells (PTC)1,2,3.
Previous techniques used to study renal filtration and establishing the characteristic of the filtration barrier involved micropuncture of the lumen of these early tubular segments with sampling of the fluid content and analysis4. These studies determined albumin concentration in the luminal fluid to be virtually non-existent; corresponding closely to what is normally detected in the urine. However, characterization of dextran polymers with defined sizes by this technique revealed those of a size similar to serum albumin had higher levels in the tubular lumen and urine; suggesting increased permeability5.
Herein is a detailed outline of the technique used to directly visualize and quantify glomerular fluorescent albumin permeability in vivo. This method allows for detection of filtered albumin across the filtration barrier into Bowman's space (the initial chamber of urinary filtration); and also allows quantification of albumin reabsorption by proximal tubules and visualization of subsequent albumin transcytosis6. The absence of fluorescent albumin along later tubular segments en route to the bladder highlights the efficiency of the retrieval pathway in the earlier proximal tubule segments. Moreover, when this technique was applied to determine permeability of dextrans having a similar size to albumin virtually identical permeability values were reported2. These observations directly support the need to expand the focus of many proteinuric renal diseases to included alterations in proximal tubule cell reclamation.

A technique utilizing high resolution intavital 2-photon microscopy to directly visualize and quantify gloemrular filtration in surface glomeruli. This method allows for direct determination of permeability characteristics of macromolecules in both normal and diseased states.

Kidney  diseases involving urinary loss of large essential macromolecules, such as  serum albumin, have long been thought to be caused by alterations in ...

A Contusion Model of Severe Spinal Cord Injury in Rats

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is described to obtain a consistent model of severe SCI. Use of a stereotactic frame and computer controlled impactor allows for creation of reproducible injury. Hypothermia and urinary tract infection pose significant challenges in the post-operative period. Careful monitoring of animals with daily weight recording and bladder expression allows for early detection of post-operative complications. The functional results of this contusion model are equivalent to transection models. The contusion model can be utilized to evaluate the efficacy of both neuroprotective and neuroregenerative approaches.

A contusion model of severe spinal cord injury is described. Detailed pre-operative, operative and post-operative steps are described to obtain a consistent model.

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is ...

Adjustable Stiffness, External Fixator for the Rat Femur Osteotomy and Segmental Bone Defect Models

The mechanical environment around the healing of broken bone is very important as it determines the way the fracture will heal. Over the past decade there has been great clinical interest in improving bone healing by altering the mechanical environment through the fixation stability around the lesion. One constraint of preclinical animal research in this area is the lack of experimental control over the local mechanical environment within a large segmental defect as well as osteotomies as they heal. In this paper we report on the design and use of an external fixator to study the healing of large segmental bone defects or osteotomies. This device not only allows for controlled axial stiffness on the bone lesion as it heals, but it also enables the change of stiffness during the healing process in vivo. The conducted experiments have shown that the fixators were able to maintain a 5 mm femoral defect gap in rats in vivo during unrestricted cage activity for at least 8 weeks. Likewise, we observed no distortion or infections, including pin infections during the entire healing period. These results demonstrate that our newly developed external fixator was able to achieve reproducible and standardized stabilization, and the alteration of the mechanical environment of in vivo rat large bone defects and various size osteotomies. This confirms that the external fixation device is well suited for preclinical research investigations using a rat model in the field of bone regeneration and repair.

One constraint of preclinical research in the field of bone repair is the lack of experimental control over the local mechanical environment within a healing bone lesion. We report the design and use of an external fixator for bone repair with the ability to change fixator stiffness in vivo.

The mechanical environment around the healing of broken bone is very important as it determines the way the fracture will heal. Over the past decade there ...

A Novel Model of Mild Traumatic Brain Injury for Juvenile Rats

Despite growing evidence that childhood represents a major risk period for mild traumatic brain injury (mTBI) from sports-related concussions, motor vehicle accidents, and falls, a reliable animal model of mTBI had previously not been developed for this important aspect of development. The modified weight-drop technique employs a glancing impact to the head of a freely moving rodent transmitting acceleration, deceleration, and rotational forces upon the brain. When applied to juvenile rats, this modified weight-drop technique induced clinically relevant behavioural outcomes that were representative of post-concussion symptomology. The technique is a rapidly applied procedure with an extremely low mortality rate, rendering it ideal for high-throughput studies of therapeutics. In addition, because the procedure involves a mild injury to a closed head, it can easily be used for studies of repetitive brain injury. Owing to the simplistic nature of this technique, and the clinically relevant biomechanics of the injury pathophysiology, the modified weight-drop technique provides researchers with a reliable model of mTBI that can be used in a wide variety of behavioural, molecular, and genetic studies.

The modified weight-drop technique is an easy, cost-effective procedure used for the induction of mild traumatic brain injury in juvenile rats. This novel technique produces clinically relevant symptomology that will advance the study of mild traumatic brain injury (mTBI) and concussion.

Despite growing evidence that childhood represents a major risk period for mild traumatic brain injury (mTBI) from sports-related concussions, motor ...

Studying Pancreatic Cancer Stem Cell Characteristics for Developing New Treatment Strategies

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor initiation, metastasis and resistance to radio- and chemotherapy. Here we describe a specific methodology for culturing primary human pancreatic CSCs as tumor spheres in anchorage-independent conditions. Cells are grown in serum-free, non-adherent conditions in order to enrich for CSCs while their more differentiated progenies do not survive and proliferate during the initial phase following seeding of single cells. This assay can be used to estimate the percentage of CSCs present in a population of tumor cells. Both size (which can range from 35 to 250 micrometers) and number of tumor spheres formed represents CSC activity harbored in either bulk populations of cultured cancer cells or freshly harvested and digested tumors 1,2. Using this assay, we recently found that metformin selectively ablates pancreatic CSCs; a finding that was subsequently further corroborated by demonstrating diminished expression of pluripotency-associated genes/surface markers and reduced in vivo tumorigenicity of metformin-treated cells. As the final step for preclinical development we treated mice bearing established tumors with metformin and found significantly prolonged survival. Clinical studies testing the use of metformin in patients with PDAC are currently underway (e.g., NCT01210911, NCT01167738, and NCT01488552). Mechanistically, we found that metformin induces a fatal energy crisis in CSCs by enhancing reactive oxygen species (ROS) production and reducing mitochondrial transmembrane potential. In contrast, non-CSCs were not eliminated by metformin treatment, but rather underwent reversible cell cycle arrest. Therefore, our study serves as a successful example for the potential of in vitro sphere formation as a screening tool to identify compounds that potentially target CSCs, but this technique will require further in vitro and in vivo validation to eliminate false discoveries.

Pancreatic cancer stem cells (CSCs) can be expanded in vitro using the anchorage-independent sphere culture technique, which represents a powerful tool to study CSC biology and can serve as the first step to develop novel CSC-targeting therapies. Here the methodology for expanding, analyzing and targeting of pancreatic CSCs is provided.

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor ...

Heterotopic Renal Autotransplantation in a Porcine Model: A Step-by-Step Protocol

Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality of life when compared to dialysis. Although the last few decades have seen major improvements in patient outcomes following kidney transplantation, the increasing shortage of available organs represents a severe problem worldwide. To expand the donor pool, marginal kidney grafts recovered from extended criteria donors (ECD) or donated after circulatory death (DCD) are now accepted for transplantation. To further improve the postoperative outcome of these marginal grafts, research must focus on new therapeutic approaches such as alternative preservation techniques, immunomodulation, gene transfer, and stem cell administration.
Experimental studies in animal models are the final step before newly developed techniques can be translated into clinical practice. Porcine kidney transplantation is an excellent model of human transplantation and allows investigation of novel approaches. The major advantage of the porcine model is its anatomical and physiological similarity to the human body, which facilitates the rapid translation of new findings to clinical trials. This article offers a surgical step-by-step protocol for an autotransplantation model and highlights key factors to ensure experimental success. Adequate pre- and postoperative housing, attentive anesthesia, and consistent surgical techniques result in favorable postoperative outcomes. Resection of the contralateral native kidney provides the opportunity to assess post-transplant graft function. The placement of venous and urinary catheters and the use of metabolic cages allow further detailed evaluation. For long-term follow-up studies and investigation of alternative graft preservation techniques, autotransplantation models are superior to allotransplantation models, as they avoid the confounding bias posed by rejection and immunosuppressive medication.

Porcine models of organ transplantation provide an important platform to study mechanisms of organ preservation. This article describes a heterotopic porcine renal autotransplantation model, which allows investigating new approaches to improve the outcome of transplantation using marginal kidney grafts.

Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality ...

A Reproducible Intensive Care Unit-Oriented Endotoxin Model in Rats

Sepsis and septic shock remain the leading cause of death in intensive care units. Despite significant improvements in sepsis management, mortality still ranges between 20 and 30%. Novel treatment approaches in order to reduce sepsis-related multiorgan failure and death are urgently needed. Robust animal models allow for one or multiple treatment approaches as well as for testing their effect on physiological and molecular parameters. In this article, a simple animal model is presented.
First, general anesthesia is induced in animals either with the use of volatile or by intraperitoneal anesthesia. After placement of an intravenous catheter (tail vein), tracheostomy, and insertion of an intraarterial catheter (tail artery), mechanical ventilation is started. Baseline values of mean arterial blood pressure, arterial blood oxygen saturation, and heart rate are recorded.
The injection of lipopolysaccharides (1 milligram/kilogram body weight) dissolved in phosphate-buffered saline induces a strong and reproducible inflammatory response via the toll-like receptor 4. Fluid corrections as well as the application of norepinephrine are performed based on well-established protocols.
The animal model presented in this article is easy to learn and strongly oriented towards clinical sepsis treatment in an intensive care unit with sedation, mechanical ventilation, continuous blood pressure monitoring, and repetitive blood sampling. Also, the model is reliable, allowing for reproducible data with a limited number of animals in accordance with the 3R (reduce, replace, refine) principles of animal research. While animal experiments in sepsis research cannot easily replaced, repetitive measurements allow for a reduction of animals and keeping septic animals anesthetized diminishes suffering.

Here, we present a reproducible intensive care unit-oriented endotoxin model in rats.

Sepsis and septic shock remain the leading cause of death in intensive care units. Despite significant improvements in sepsis management, mortality still ...

A Protocol for Roux-en-Y Gastric Bypass in Rats using Linear Staplers

Roux-en-Y gastric bypass (RYGB) is commonly performed for the treatment of severe obesity and type 2 diabetes. However, the mechanism of weight loss and metabolic changes are not well understood. Multiple factors are thought to play a role, including reduced caloric intake, decreased nutrient absorption, increased satiety, the release of satiety-promoting hormones, shifts in bile acid metabolism, and alterations in the gut microbiota.
The rat RYGB model presents an ideal framework to study these mechanisms. Prior work on mouse models have had high mortality rates, ranging from 17 to 52%, limiting their adoption. Rat models demonstrate more physiologic reserve to surgical stimulus and are technically easier to adopt as they allow for the use of surgical staplers. One challenge with surgical staplers, however, is that they often leave a large gastric pouch which is not representative of RYGB in humans. 
In this protocol, we present a RYGB protocol in rats that result in a small gastric pouch using surgical staplers. Utilizing two stapler fires which remove the forestomach of the rat, we obtain a smaller gastric pouch similar to that following a typical human RYGB. Surgical stapling also results in better hemostasis than sharp division. Additionally, the forestomach of the rat does not contain any glands and its removal should not alter the physiology of RYGB.
Weight loss and metabolic changes in the RYGB cohort were significant compared to the sham cohort, with significantly lower glucose tolerance at 14 weeks. Furthermore, this protocol has an excellent survival of 88.9% after RYGB. The skills described in this protocol can be acquired without previous microsurgical experience. Once mastered, this procedure will provide a reproducible tool for studying the mechanisms and effects of RYGB.

Roux-en-Y gastric bypass (RYGB) is performed to treat obesity and diabetes. However, the mechanisms underlying RYGB's efficacy are not fully understood, and studies are limited by technical difficulty leading to high mortality in animal models. This article provides instructions on how to perform RYGB in rats with high success rates.

Roux-en-Y gastric bypass (RYGB) is commonly performed for the treatment of severe obesity and type 2 diabetes. However, the mechanism of weight loss and ...

A Protocol for Constructing a Rat Wound Model of Type 1 Diabetes

A single high dose of streptozotocin injection followed by full-thickness skin excision on the dorsum of rats is a common method for constructing animal models of type 1 diabetic wounds. However, improper manipulation can lead to model instability and high mortality in rats. Unfortunately, there are few existing guidelines on type 1 diabetic wound modeling, and they lack detail and do not present specific reference strategies. Therefore, this protocol details the complete procedure for constructing a type 1 diabetic wound model and analyzes the progression and angiogenic characteristics of the diabetic wounds. Type 1 diabetic wound modeling involves the following steps: preparation of the streptozotocin injection, induction of type 1 diabetes mellitus, and construction of the wound model. The wound area was measured on day 7 and day 14 after wounding, and the skin tissues of the rats were extracted for histopathological and immunofluorescence analysis. The results revealed that type 1 diabetes mellitus induced by 55 mg/kg streptozotocin was associated with lower mortality and a high success rate. The blood glucose levels were relatively stable after 5 weeks of induction. The diabetic wound healing rate was significantly lower than that of normal wounds on day 7 and day 14 (p &#60; 0.05), but both could reach more than 90% on day 14. Compared with the normal group, the epidermal layer closure of diabetic wounds on day 14 was incomplete and had delayed re-epithelialization and significantly lower angiogenesis (p &#60; 0.01). The type 1 diabetic wound model constructed based on this protocol has the characteristics of chronic wound healing, including poor closure, delayed re-epithelialization, and decreased angiogenesis compared to normal rat wounds.

The streptozotocin-induced diabetic wound model in male SD rats is currently the most widely used model for studying wound healing in type I diabetes mellitus. This protocol describes the methods used to construct this model. It also presents and addresses potential challenges and examines the progression and angiogenic characteristics of diabetic wounds.

A single high dose of streptozotocin injection followed by full-thickness skin excision on the dorsum of rats is a common method for constructing animal ...

Subclavian Vein Puncture Method for Repeated Blood Collection in Conscious Rats

Subclavian Vein Blood Sampling in Conscious Rats

There are several established methods for obtaining repeated blood samples from rats, with the most commonly employed methods being lateral tail vein sampling without anesthesia and jugular vein sampling with anesthesia. However, most of these methods require assistance and anesthetic equipment and sometimes pose difficulties in terms of blood collection or the poor quality of blood samples. In addition, these methods of blood collection consume significant time and human resources when repeated blood sampling is required for a large number of rats. This study presents a technique for repetitive blood sampling in non-anesthetized rats by a single proficient individual. Highly satisfactory blood samples can be obtained by puncturing the subclavian vein. The method demonstrated an impressive overall success rate of 95%, with a median time of merely 2 min from rat restraint to the completion of blood collection. Furthermore, performing consecutive blood collections within the designated range does not inflict any harm on the rats. This method is worth promoting for blood collection, especially in large-scale pharmacokinetic studies.

Author Spotlight: Developing an Efficient Blood Collection Method in Non-Anesthetized Rats 

Here we present a combination of effective rat restriction and subclavian vein puncture methods that enable rapid, safe, and repeated blood collection in rats without anesthesia.

There are several established methods for obtaining repeated blood samples from rats, with the most commonly employed methods being lateral tail vein ...