This work was supported by the National Natural Science Foundation of China (81973607) and Essential Drug Research and Development (2019ZX09201004-003-032) from Ministry of Science and Technology of China.

The investigations described conform to the Guidelines for the Care and Use of Laboratory Animals of the National Institutes of Health and were approved by Shanghai University of Traditional Chinese Medicine Animal Care and Use Committee. All surgical manipulations were performed under deep anesthesia and the animals did not experience pain at any stage during the procedure.
1. Pre-operation preparation
<ol>
	<li>Instrument sterilization: Steam-sterilize surgical instruments in an autoclave ...

<ol>
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E., Coulson, W. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+collagenase+upon+the+intervertebral+disc+in+monkeys.">Effects of collagenase upon the intervertebral disc in monkeys.</a> Journal of Neurosurgery. 44 (1), 32-44 (1976).</li><li>Silva, M. J., Holguin, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=LRP5-deficiency+in+OsxCreERT2+mice+models+intervertebral+disc+degeneration+by+aging+and+compression.">LRP5-deficiency in OsxCreERT2 mice models intervertebral disc degeneration by aging and compression.</a> bioRxiv. , (2019).</li><li>Nemoto, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histological+changes+in+intervertebral+discs+after+smoking+and+cessation:+experimental+study+using+a+rat+passive+smoking+model.">Histological changes in intervertebral discs after smoking and cessation: experimental study using a rat passive smoking model.</a> Journal of Orthopaedic Science: Official Journal of the Japanese Orthopaedic Association. 11 (2), 191-197 (2006).</li><li>Mulholland, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+myth+of+lumbar+instability:+the+importance+of+abnormal+loading+as+a+cause+of+low+back+pain.">The myth of lumbar instability: the importance of abnormal loading as a cause of low back pain.</a> European Spine Journal. 17 (5), 619-625 (2008).</li><li>Bian, Q., 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=Mechanosignaling+activation+of+TGF&#946;+maintains+intervertebral+disc+homeostasis.">Mechanosignaling activation of TGF&#946; maintains intervertebral disc homeostasis.</a> Bone Research. 5, 17008 (2017).</li><li>Bian, Q., 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=Excessive+activation+of+tgf&#946;+by+spinal+instability+causes+vertebral+endplate+sclerosis.">Excessive activation of tgf&#946; by spinal instability causes vertebral endplate sclerosis.</a> Scientific Reports. 6, 27093 (2016).</li><li>Ni, S., 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=Sensory+innervation+in+porous+endplates+by+Netrin-1+from+osteoclasts+mediates+PGE2-induced+spinal+hypersensitivity+in+mice.">Sensory innervation in porous endplates by Netrin-1 from osteoclasts mediates PGE2-induced spinal hypersensitivity in mice.</a> Nature Communications. 10 (1), 5643 (2019).</li><li>Liu, S., Cheng, Y., Tan, Y., Dong, J., Bian, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ligustrazine+prevents+intervertebral+disc+degeneration+via+suppression+of+aberrant+tgf&#946;+activation+in+nucleus+pulposus+cells.">Ligustrazine prevents intervertebral disc degeneration via suppression of aberrant tgf&#946; activation in nucleus pulposus cells.</a> BioMed Research International. 2019, 5601734 (2019).</li><li>Boos, N., 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=Classification+of+age-related+changes+in+lumbar+intervertebral+discs:+2002+Volvo+Award+in+basic+science.">Classification of age-related changes in lumbar intervertebral discs: 2002 Volvo Award in basic science.</a> Spine. 27 (23), 2631-2644 (2002).</li><li>Miyamoto, S., Yonenobu, K., Ono, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+cervical+spondylosis+in+the+mouse.">Experimental cervical spondylosis in the mouse.</a> Spine. 16, 495-500 (1991).</li></ol>

We developed the lumbar spine instability mouse model based on the cervical spondylosis mouse model in which the posterior paravertebral muscles from the vertebrae were detached and the spinous processes along with the supraspinous and interspinous ligaments were resected25. We performed a similar operation onto the lumbar spine, which has more prominent spinous processes. The LSI mouse model developed similar IDD in the lumbar spine.
The advantages of the LSI model inc...

Intervertebral disc degeneration (IDD) is commonly seen in aging and even young people caused by many factors1. Surgery for patients who suffer from IDD, causing low back pain and impaired movement, is usually performed at a later stage or in severe cases and has potential risks such as nonunion or infection2. Ideal non-operative treatment requires comprehensive understanding of the IDD mechanism. The IDD animal model serves as a crucial tool for studies of IDD mechanism and evaluation of IDD treatment.
Larger animals have been chosen for IDD models such as primates, sheep, goats, dogs, and rabbits due to their similarity with human anatomical structure to a great extent and the strong operability in terms of size of intervertebral discs (IVDs)3,4,5,6,7,8. However, these animal models are time-consuming and cost-intensive9. Mouse IVD is a poor representation of the human IVD based on geometrical measurements of the aspect ratio, nucleus pulposus to disc area ratio, and normalized height10. Despite the difference in size, mouse lumbar IVD segment exhibits mechanical properties similar to human IVD such as compression and torsion stiffness11. In addition, mouse IDD model has the advantage of low cost, relatively short IDD development, and more options for genetically modified animals and antibodies utilized in further mechanistic studies12,13,14,15.
Experimental-induced IDD models vary from the inducers and applications. For example, collagenase-induced extracellular matrix (ECM) degeneration is appropriate for ECM regeneration research16. Genetically modified phenotype are suitable for studying the gene function in the IDD process and in genetic therapies17. Annulus fibrosus incision and smoke models mimic trauma and non-inflammation induced IDD12,18.
Spinal instability (SI) leads to an unstable spine that is not in an optimal state of equilibrium. It can be caused by abnormal movement of a lumbar motion segment due to the weakness of the surrounding supportive tissue such as ligaments and muscles. It is also commonly seen post spinal fusion operation19. SI is considered as the main cause of IDD. Therefore, we aim to develop a SI mice model (focused on lumbar spine) that mimics the human IDD process20,21.
In the protocol, we introduced the procedure of establishing lumbar spinal instability (LSI) mouse model by the resection of lumbar third (L3) to lumbar fifth (L5) spinous processes along with the supraspinous and interspinous ligaments (Figure 1A,B). The animal model develops IDD as early as 1-week post-surgery as shown by hypertrophy and porosity in endplates (EPs). IVD volume starts to decrease 2 weeks post-surgery through 16 weeks along with increased IVD score, which indicates the degree of IDD. We believe the detailed and visualized procedure is useful for researchers to establish the LSI mouse model in their laboratory and apply to IDD research as needed.

<table>
	<tbody>
		<tr>
			<td>Chlortetracycline Hydrochloride Eye Ointment</td>
			<td>Shanghai General Pharmaceutical Co., Ltd.</td>
			<td>H31021931</td>
			<td>Prevent eye dry, Prevent wound infection</td>
		</tr>
		<tr>
			<td>C57BL/6J male mice</td>
			<td>Tian-jiang Pharmaceuticals Company (Jiangsu, CN)</td>
			<td>SCXK2018-0004</td>
			<td>Animal model</td>
		</tr>
		<tr>
			<td>Disposable medical towel</td>
			<td>Henan Huayu Medical Devices Co., Ltd.</td>
			<td>20160090</td>
			<td>Platform for surgical operation</td>
		</tr>
		<tr>
			<td>Inhalant anesthesia equipment</td>
			<td>MIDMARK</td>
			<td>Matrx 3000</td>
			<td>Anesthesia</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Shenzhen RWD Life Technology Co., Ltd.</td>
			<td>1903715</td>
			<td>Anesthesia</td>
		</tr>
		<tr>
			<td>Lidocaine hydrochloride</td>
			<td>Shandong Hualu Pharmaceutical Co., Ltd.</td>
			<td>H37022839</td>
			<td>Pain relief</td>
		</tr>
		<tr>
			<td>Medical suture needle</td>
			<td>Shanghai Pudong Jinhuan Medical Products Co., Ltd.</td>
			<td>20S0401J</td>
			<td>Suture skin</td>
		</tr>
		<tr>
			<td>Ophthalmic forceps</td>
			<td>Shanghai Medical Devices (Group) Co., Ltd. Surgical Instruments Factory</td>
			<td>JD1050</td>
			<td>Clip the skin</td>
		</tr>
		<tr>
			<td>Ophthalmic scissors(10cm)</td>
			<td>Shanghai Medical Devices (Group) Co., Ltd. Surgical Instruments Factory</td>
			<td>Y00030</td>
			<td>Skin incision</td>
		</tr>
		<tr>
			<td>silk braided</td>
			<td>Shanghai Pudong Jinhuan Medical Products Co., Ltd.</td>
			<td>11V0820</td>
			<td>Suture skin</td>
		</tr>
		<tr>
			<td>Small animal trimmer</td>
			<td>Shanghai Feike Electric Co., Ltd.</td>
			<td>FC5910</td>
			<td>Hair removal</td>
		</tr>
		<tr>
			<td>Sterile surgical blades(12#)</td>
			<td>Shanghai Pudong Jinhuan Medical Products Co., Ltd.</td>
			<td>35T0707</td>
			<td>Muscle incision</td>
		</tr>
		<tr>
			<td>Veet hair removal cream</td>
			<td>RECKITT BENCKISER (India) Ltd</td>
			<td>NA</td>
			<td>Hair removal</td>
		</tr>
		<tr>
			<td>Venus shears</td>
			<td>Mingren medical equipment</td>
			<td>Length:12.5cm</td>
			<td>Clip the muscle and spinous process</td>
		</tr>
	</tbody>
</table>

a mouse model of lumbar spine instability

Intervertebral disc degeneration (IDD) is a common pathological change leading to low back pain. Appropriate animal models are desired for understanding the pathological processes and evaluating new drugs. Here, we introduced a surgically induced lumbar spine instability (LSI) mouse model that develops IDD starting from 1 week post operation. In detail, the mouse under anesthesia was operated by low back skin incision, L3&#8211;L5 spinous processes exposure, detachment of paraspinous muscles, resection of processes and ligaments, and skin closure. L4&#8211;L5 IVDs were chosen for the observation. The LSI model develops lumbar IDD by porosity and hypertrophy in endplates at an early stage, decrease in intervertebral disc volume, shrinkage in nucleus pulposus at an intermediate stage, and bone loss in lumbar vertebrae (L5) at a later stage. The LSI mouse model has the advantages of strong operability, no requirement of special equipment, reproducibility, inexpensive, and relatively short period of IDD development. However, LSI operation is still a trauma that causes inflammation within the first week post operation. Thus, this animal model is suitable for study of lumbar IDD.

The LSI mouse model is applied in the studies of IDD mechanism, IDD treatment, endplate (EP) degeneration such as sclerosis, and sensory innervation in EP20,21,22,23. The LSI mouse develops IDD and EP degenerative changes, as identified, by decreased IVD volume and height, increased EP volume, and increased IVD and EP scores.
The dissected and fixed lower thoracic an...

Watch this Scientific Journal Video about A Mouse Model of Lumbar Spine Instability at JoVE.com

A Mouse Model of Lumbar Spine Instability

We developed a lumbar intervertebral disc degeneration mouse model by resection of L3&#8211;L5 spinous processes along with supra- and inter-spinous ligaments and detachment of paraspinous muscles.

Intervertebral disc degeneration (IDD) is a common pathological change leading to low back pain. Appropriate animal models are desired for understanding ...

This is a surgery to induce the mouse model offers an alternative for lumbar intervertebral disc degeneration related studies. This robust LSI mode requires no special equipment. It's reproducible and it can be used to induce the intervertebral disc degeneration in a relatively short period of time.Controlling the incision depths and the hemorrhage and perform for resection of each interspinous process are two key expense for implantation of our success for experiment. After confirming a lack of response to pedal reflex, place an anesthetized eight week old, male, C57 black six mouse onto a surgical pad in the supine position and apply ointment to the animal's eyes. Use a small animal trimmer to shave the surgical area from the lower thoracic region to the top of the sacral region and remove the shaved fur with tissue wipes.Apply depilatory cream to the shaved area using gauze to remove the cream after no more than three minutes and flush the exposed skin with two milliliters of 0.9 sterile saline. Then place a custom-made surgical cylindrical pad under the abdomen to raise the lumbar spine. To expose the L3 and L5 vertebrae use the index finger to touch the subcutaneous spinous processes of the lumbar vertebrae and palpate to compare the processes with those of the thoracic vertebrae and sacral vertebrae to identify the lumbar region.Rinse the skin with 75%alcohol, and using a dissecting microscope use a scalpel to make a three to four centimeter midline skin incision over the lumbar region from the mid thoracic region to the hip. Identify the lumbar spine by the V-shape of the posterior fascia inserted, into the tip so the spinous processes and use the scalpel to make shallow posterior paraspinous muscle incisions along the spinous processes from L3 to L5 laterally on both sides of the spine. Then use two pairs of ophthalmic forceps to separate the muscle layers to expose the L3 to L5 spinous processes and supraspinous ligaments.To separate individual spinous processes use venous sheers to cut off interspinous ligaments and to resect the L3 to L5 spinous processes and interspinous ligaments. Then use sterile number five silk braided sutures to close the skin incision without reattaching the paravertebral muscles and apply chlortetracycline hydrochloride ointment to the surgical site. 3D histomorphometric analysis allows intervertebral disc measurement, while 3D structural analysis allows quantification of the total tissue volume.The intervertebral disc volume significantly increases one week after surgery before decreasing two to 16 weeks after the procedure consistent with a decrease in the intervertebral disc height measured over the same time period. Increased cavities within the cranial endplates are also observed in LSI mice as quantified by an increased percentage of trabecular separation values greater or equal to 0.089 and a significant increase in the endplate volumes post-surgery. Model endplates exhibit a similar phenotype, indicating that LSI leads to endplate hypertrophy and an increase in cavity number.L5 vertebra volumes slightly increase post-surgery with statistical differences observed at 16 weeks. A significant decrease in the bone to total tissue volume ratio is also present 16 weeks after surgery, indicating that LSI causes vertebral bone loss at a later stage. A reduction in intracellular vacuoles of nucleus pulposus cells is also accelerated in LSI animals with increased numbers of osteoclasts observed in LSI endplates.This model can be modified by attaching different number of vertebrae, such as the fifth lumbar only, or from first lumbar to fifth lumbar.

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7.1K visualizações.  Shanghai University of Traditional Chinese Medicine. Trata-se de uma cirurgia para induzir o modelo de camundongos que oferece uma alternativa para estudos relacionados à degeneração do disco intervertebral lombar. Este modo LSI robusto não requer nenhum equipamento especial. É reprodutível e pode ser usado para induzir a degeneração do disco intervertebral em um período relativamente curto de tempo.Controlar as profundidades de incisão e a hemorragia e realizar a ressecção de cada processo interspino são duas despesas funda...