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>

None of the authors have any conflicts of interest or any other financial disclosures.

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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2.5K Views.  All India Institute of Medical Sciences (AIIMS). 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 he...