Name: ovine lumbar intervertebral disc degeneration model utilizing a lateral retroperitoneal drill bit injury
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Dr. Chris Daly is the recipient of the Foundation for Surgery Richard Jepson Research Scholarship. The authors would like to thank Dr. Anne Gibbon, Dr. Dong Zhang and the staff of Monash Animal Services, Monash University for their assistance with animal surgery and care.

The protocol detailed in this manuscript follows the animal care guidelines of Monash University Animal Ethics. Animal ethics approval for this protocol has been granted by Monash University Animal Ethics. Ethics approval number: MMCA/2014/55
1. Sheep Preparation
NOTE: Ewes aged two to four years were used.
<ol>
	<li>Fast sheep for 18 h prior to anesthesia. Provide animals with access to water until 6-12 h prior to operation19.</li>
	<li>Sedate animals by intravenous injection of medetomidine hydrochloride (0.015-0.020 mg/kg) to facilitate transfer to operating suite. 
	NOTE: The medetomidine hydrochloride serves to reduce animal stress and agitation associated with separation from other animals for transfer to the operating suite.</li>
	<li>Inject thiopentone (10-13 mL/kg) for induction of anesthesia upon arrival to the operating suite.</li>
	<li>Administer prophylactic intravenous antibiotics (amoxicillin 1 g IV) immediately following thiopentone injection.</li>
	<li>Intubate sheep using a size 7.5-9 mm (internal diameter) endotracheal tube20.</li>
	<li>Maintain anesthesia using inhaled isoflurane (2-3%) in 100% oxygen at a flow rate of 2 L/min. Attach a pulse oximeter to the sheep&#39;s ear.</li>
	<li>Closely monitor the sheep&#39;s vital signs (heart rate, respiratory rate and oxygen saturation via pulse oximeter and observation) and level of consciousness. 
	NOTE: Indicators of light anesthesia such as spontaneous chewing, active regurgitation, and spontaneous movements should prompt increase in the level of anesthesia. Red flag signs indicating urgent lightening of anesthesia include respiratory compromise and severe bradycardia. Rotation of the eye is not a consistent indicator of depth of anesthesia in sheep19.</li>
</ol>
2. Disc Level and Incision
<ol>
	<li>Collect the surgical tools needed for this procedure: veterinary clippers, 20 mL luer-lock syringe, 21G IV Needle, #4 scalpel handle, #22 scalpel blades, Gillies tissue forceps, Metzenbaum curved dissecting scissors, Deaver retractor, Hohmann retractor blade, 3.5 mm Brad point drill bit, drill bit stop, drill, autoclavable veterinary drill bag, needle holder, 2-0 absorbable synthetic braided sutures, 3-0 absorbable synthetic braided suture and Mayo suture scissors.</li>
	<li>Prepare the operating suite. Clean the operative table and instrument stand with 70% ethanol. Autoclave all surgical instruments prior to operation. Perform pre-operative anesthetic check.</li>
	<li>Place the sheep on the operating table in the right lateral position.</li>
	<li>Using electronic clippers, shave the region defined superiorly by the lower ribs, inferiorly by the iliac bone, medially by the contralateral lumbar transverse processes and approximately 10 cm lateral to the ipsilateral lumbar transverse processes.</li>
	<li>Palpate the iliac crest, lumbar transverse processes (L1-6) and costo-vertebral angle for the landmarks for surgical incision site. Mark these landmarks with a sterile pen.</li>
	<li>Prepare the lateral abdomen by disinfecting with chlorhexidine and alcoholic-iodide antiseptic wash.</li>
	<li>Observe standard surgical aseptic techniques throughout the operation. The surgical team scrubs prior to the operation. Place a sterile fenestrated square drape over the surgical site, and a large sterile square drape on the overhead table.
	<ol>
		<li>Sterilize all items to be used within the operative site prior to the operation. Monitor and maintain sterility of the surgical site throughout the operation. Ensure all items introduced into the sterile field are sterile and transferred in a sterile fashion.</li>
	</ol>
	</li>
	<li>Use surgical loupe magnification and a headlight to facilitate visualization during the surgical procedure.</li>
	<li>Make a longitudinal incision using the #22 scalpel blade attached to the #4 scalpel handle parallel to and 1 cm anterior to one to two lumbar transverse processes above and below the intervertebral disc levels of interest. 
	NOTE: Further information regarding incision planning can be found in the discussion.</li>
	<li>Use the monopolar diathermy to divide the underlying subcutaneous tissue and the lateral aspect of the abdominal wall musculature; direct the dissection towards the tips of the lumbar transverse processes above and below the intervertebral discs of interest.</li>
	<li>Divide the thoracolumbar fascia longitudinally at its attachment to the transverse processes.</li>
	<li>Visualize and preserve the underlying quadratus lumborum, psoas muscles and the traversing neurovascular bundles.</li>
	<li>Maintain hemostasis through the procedure using diathermy.</li>
	<li>Sweep the fingers between the plane of the peritoneum and posterior abdominal wall musculature at the exposed intervertebral disc levels to perform digital blunt dissection.</li>
	<li>Retract the quadratus lumborum and psoas muscles posterolaterally using a Deaver retractor to further expose of the intervertebral discs.</li>
	<li>Palpate for the concave intervertebral bodies and the convex intervertebral discs.</li>
	<li>Position the retractors immediately over the discs and take care to ensure lumbar vessels are not damaged.</li>
	<li>Using surgical loupe magnification with a headlight, identify the lumbar vessels which are located approximately 1 cm caudal to the inferior endplate.</li>
	<li>Perform an intraoperative lateral X-ray to confirm the disc level.21 
	Note: Radiograph settings: 47kV; 4 mAs21</li>
	<li>Depending on the disc levels desired, expose the intervertebral disc by separating the surrounding structures and attachments as below.
	<ol>
		<li>For levels L3/4 and above, sweep aside the muscular attachments over the disc using digital blunt dissections.</li>
		<li>For levels L4/5 and below, sharply divide the thicker tendinous muscular attachments over the disc using bipolar diathermy and scissors. 
		NOTE: L6/S1 disc can be difficult to access due to obstruction by the iliac crest. If access cannot be accomplished via the lateral approach an anterior approach may be utilized.</li>
	</ol>
	</li>
</ol>
3. Drill Bit Injury
NOTE: Pre-operative planning includes the allocation of injury/treatment levels and control levels. Further information regarding level allocation can be found in the discussion.
<ol>
	<li>Define the drill bit entry point by observing the left lateral and anterior extremities of the intervertebral disc. 
	NOTE: The entry point is located at the midpoint of this left anterolateral quadrant (defined by the anterior and lateral extremities of the disc). The drill bit is inserted at this entry point with a trajectory aimed towards the center of the intervertebral discs and directed slightly cranial to perpendicular.</li>
	<li>Fit a Brad-point drill bit into the power drill. Ensure the diameter of the drill bit is slightly less than the intervertebral disc height i.e. ~3.5 mm for lumbar intervertebral disc in 60-70 kg sheep.
	<ol>
		<li>Apply a drill bit stop to provide an unprotected drill bit length of approximately half the diameter of the lumbar intervertebral disc i.e. ~12 mm for lumbar intervertebral discs in 60-70 kg sheep.</li>
	</ol>
	</li>
	<li>Apply the drill bit to the entry point and direct it in a trajectory slightly cranial to the center of the intervertebral disc. The slight cranial angulation is to minimize the risk of endplate injury.</li>
	<li>Advance the drill bit slowly into the intervertebral disc with the drill on low power for 1 s. Adjust the trajectory in a slight cranial or caudal fashion if excessive resistance is encountered 
	NOTE: Such excessive resistance likely indicates contact with the endplate.</li>
</ol>
4. Closure
<ol>
	<li>Once hemostasis is achieved, irrigate the wound with Ringers&#39; solution.</li>
	<li>Perform layered closure, preferably using 2-0 absorbable synthetic braided sutures to the lateral abdominal wall tissues and continuous 3-0 undyed absorbable synthetic braided subcuticular suture to the skin.</li>
</ol>
5. Post-operative Management
<ol>
	<li>Place a fentanyl transdermal patch (75 &#181;g/h) in the inguinal region for post-surgical analgesia for 3 days.</li>
	<li>Additionally, use intravenous buprenorphine (0.005-0.01 mg/kg) for top-up analgesia if needed.</li>
	<li>Cease the inhalational anesthetic. When spontaneous breathing occurs, remove the endotracheal tube.</li>
	<li>Allow the animal to recover in a holding cage under constant observation. 
	NOTE: The animal should not be left unattended until it has regained sufficient consciousness to retain sternal recumbency.</li>
	<li>Once the animal is fully alert and standing, re-introduce food and water. Once fully recovered, return the animal to its operative facility holding pen with other animals.</li>
	<li>Monitor closely for 24 h and continue observation for one week. Monitor for evidence of post-surgical pain or distress. 
	NOTE: Post-operative transdermal fentanyl patch applied for three days should provide sufficient analgesia. Additional analgesic requirements should prompt animal review.</li>
	<li>Feed the sheep normally, and allow the sheep to carry out normal activities without restriction. Observe the sheep for any evidence of neurological deficit such as lameness. 
	NOTE: The intervertebral disc defect produced by the drill bit injury method is on the anterolateral aspect of the disc and the injury depth is limited by the drill bit stop to the mid nucleus. As the neural elements are located posterior/posterolateral to the intervertebral disc, the risk of neural compromise secondary to symptomatic nucleus pulposus is remote. This anatomical characteristic of the model precludes the use of neurological examination to distinguish intervertebral disc degeneration with and without nucleus pulposus herniation.</li>
	<li>Return the sheep to the university farm to await euthanasia and necropsy at the end of the experimental period.</li>
</ol>
6. Euthanasia
<ol>
	<li>Perform sheep euthanasia at an appropriate time interval following drill bit intervertebral disc injury.</li>
	<li>Inject intravenous pentobarbitone sodium (&#62;100 mg/kg) for euthanasia.</li>
</ol>

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The authors declare they have no competing financial interests to disclose.

This minimally invasive lateral access approach is efficacious and safe with no post-operative herniae, abdominal wound dehiscence or infection observed in this series. Use of the drill bit intervertebral disc injury model with a depth stop provides a reproducible method of inducing a consistent intervertebral disc injury of known dimension (i.e. a 3.5 mm diameter x 12 mm depth injury in this study). In our experience, this method produces a less severe degree of disc degeneration than that observed in conventio...

Lower back pain is the leading cause of disability worldwide1. Lumbar intervertebral disc degeneration associated discogenic pain is considered a significant contributor to lower back pain2. There is an increasing demand for reliable animal models of intervertebral disc disease for broadening the understanding of the degenerative process and for the investigation of potential therapies.
Numerous animal models of intervertebral disc degeneration exist3. Animals models used in the investigation of degenerative disc disease range in size from mice4, to larger mammals such as dogs5, sheep6, and non-human primates7. Methods used to induce intervertebral disc degeneration can be broadly classified into the categories of mechanical (e.g. intervertebral disc compression8 or surgical injury6), chemical (e.g. chemical nucleolysis5) or, less commonly, spontaneous degeneration (e.g. the sand rat9).
Given the complexity of human intervertebral disc degeneration, a perfect animal model does not exist. However, important considerations in choosing an appropriate animal model to mimic this condition closely have been identified3. Such considerations include the absence of notochordal cells (primitive cells with possible progenitor cell function10 absent from the adult nucleus pulposus in humans, sheep, goats and chondrodystrophic dogs but present in most mammals), similarities in animal and intervertebral disc size relative to humans, comparable biomechanical forces to the clinical condition, mechanistic and ethical considerations3.
Non-human primates meet many of the above criteria. Baboon and macaque models of spontaneous intervertebral disc degeneration have been described11,12,13. Both species spend large amounts of time in erect or semi-erect postures &#8212; a distinct advantage relative to other animal models. However, ethical and practical consideration (e.g. expense, housing, delayed onset of spontaneous degeneration) restrict their use in many institutions.
The ovine spine is an established model of intervertebral disc degeneration, with advantages including cellular, biomechanical and anatomical similarities to the human spine10,14,15. Despite the quadrupedal stature of sheep the ovine lumbar intervertebral disc is exposed to similar stresses to the human disc14. The ovine model is also more widely accepted, from an ethical perspective, than non-human primate models. Varied methods have been described to initiate the degenerative process, many of which require direct access to the intervertebral disc. Due to the termination of the spinal cord in the sacral region and ossification of the posterior longitudinal ligament in the ovine lumbar spine, posterior approaches to the intervertebral disc are technically challenging and less commonly used in the sheep16. The traditional access routes to the sheep lumbar spine, i.e. via anterior or anterolateral approaches, require large abdominal incisions, are fraught with risks of hernia, and damage to internal viscera and neurovascular structures16. The use of a relatively small lateral incision away from dependent abdominal areas may decrease such risks17.
We present an ovine model of degenerative lumbar intervertebral disc disease using drill bit injury performed through a minimally invasive lateral approach, and inspired by the work of Zhang et. al18. The goal of this protocol is to enable a reliable lumbar disc injury model that is readily reproducible, produces a consistent injury, and is safe and well tolerated. This approach is well-suited to investigators seeking to induce a milder degree of lumbar intervertebral disc degeneration than that observed with traditional surgical annulotomy (unpublished data) for the investigation of either intervertebral disc degeneration or regenerative therapies. These findings will be described in a forthcoming publication.

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ovine lumbar intervertebral disc degeneration model utilizing a lateral retroperitoneal drill bit injury

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration have been developed. The ideal animal model should closely mimic the human intervertebral disc with regard to morphology, biomechanical properties and the absence of notochordal cells. The sheep lumbar intervertebral disc model fulfils these criteria. We present an ovine model of intervertebral disc degeneration utilizing a drill bit injury through a lateral retroperitoneal approach. The lateral approach significantly reduces the incision and potential morbidity associated with the traditional anterior approach to the ovine spine. Utilization of a drill-bit method of injury affords the ability to produce a consistent and reproducible injury, of precise dimensions, that initiates a consistent degree of intervertebral disc degeneration. The focal nature of the annular and nucleus pulposus defect more closely mimics the clinical condition of focal intervertebral disc herniation. Sheep recover rapidly following this procedure and are typically mobile and eating within the hour. Intervertebral disc degeneration ensues and sheep undergo necropsy and subsequent analysis at periods from eight weeks. We believe that the drill bit injury model of intervertebral disc degeneration offers advantages over more conventional annular injury models.

Pre-operatively, sheep underwent baseline 3T magnetic resonance imaging (MRI) for assessment of underlying intervertebral disc morphology and degeneration. Sheep underwent additional intra-operative lateral radiography for confirmation of intervertebral disc level and calculation of disc height index. A pre-operative sagittal plane slice from 3T MRI and an intra-operative radiograph are demonstrated in Figure 1.
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Ovine Lumbar Intervertebral Disc Degeneration Model Utilizing a Lateral Retroperitoneal Drill Bit Injury

Intervertebral disc degeneration is a significant contributor to back pain and a leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration exist. We demonstrate an ovine model of intervertebral disc degeneration, utilizing a drill bit, which achieves a consistent disc injury and reproducible level of disc degeneration.

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous ...

ovine-lumbar-intervertebral-disc-degeneration-model-utilizing-lateral

Research

JoVE Journal

Medicine

11.5K Views.  Monash University.  Intervertebrale schijfdegeneratie is een belangrijke bijdrage aan rugpijn en een belangrijke oorzaak van handicap wereldwijd. Er zijn talrijke diermodellen van de tussenwervelschijfdegeneratie. Wij tonen een schaap model van intervertebrale disc degeneratie, met behulp van een boorboor, die een consistente schade verwonding en reproduceerbare niveau van schijf degeneratie bereikt. 

Video: Ovine Lumbar Intervertebral Disc Degeneration Model Utilizing a Lateral Retroperitoneal Drill Bit Injury

Renal Ischaemia Reperfusion Injury: A Mouse Model of Injury and Regeneration

Renal ischaemia reperfusion injury (IRI) is a common cause of acute kidney injury (AKI) in patients and occlusion of renal blood flow is unavoidable during renal transplantation. Experimental models that accurately and reproducibly recapitulate renal IRI are crucial in dissecting the pathophysiology of AKI and the development of novel therapeutic agents. Presented here is a mouse model of renal IRI that results in reproducible AKI. This is achieved by a midline laparotomy approach for the surgery with one incision allowing both a right nephrectomy that provides control tissue and clamping of the left renal pedicle to induce ischaemia of the left kidney. By careful monitoring of the clamp position and body temperature during the period of ischaemia this model achieves reproducible functional and structural injury. Mice sacrificed 24 hr&#160;following surgery demonstrate loss of renal function with elevation of the serum or plasma creatinine level as well as structural kidney damage with acute tubular necrosis evident. Renal function improves and the acute tissue injury resolves during the course of 7 days following renal IRI such that this model may be used to study renal regeneration. This model of renal IRI has been utilized to study the molecular and cellular pathophysiology of AKI as well as analysis of the subsequent renal regeneration.

The mouse model of renal ischaemia reperfusion injury described here comprises of a right nephrectomy that provides control tissue and clamping of the left renal pedicle to induce ischaemia that results in acute kidney injury. This model uses a midline laparotomy approach with all steps performed via one incision.

Renal ischaemia reperfusion injury (IRI) is a common cause of acute kidney injury (AKI) in patients and occlusion of renal blood flow is unavoidable ...

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and dampen loads in the spine. The IVD consists of a proteoglycan-rich nucleus pulposus (NP) and a collagen-rich annulus fibrosis (AF) sandwiched by cartilaginous end-plates. Together with the adjacent vertebrae, the vertebrae-IVD structure forms a functional spine unit (FSU). These microstructures contain unique cell types as well as unique extracellular matrices. Whole organ culture of the FSU preserves the native extracellular matrix, cell differentiation phenotypes, and cellular-matrix interactions. Thus, organ culture techniques are particularly useful for investigating the complex biological mechanisms of the IVD. Here, we describe a high-throughput approach for culturing whole lumbar mouse FSUs that provides an ideal platform for studying disease mechanisms and therapies for the IVD. Furthermore, we describe several applications that utilize this organ culture method to conduct further studies including contrast-enhanced microCT imaging and three-dimensional high-resolution finite element modeling of the IVD.

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Whole organ culture of the intervertebral disc (IVD) preserves the native extracellular matrix, cell phenotypes, and cellular-matrix interactions. Here we describe an IVD culture system using mouse lumbar and caudal IVDs in their functional spinal units and several applications utilizing this system.

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and ...

Bioengineering

Utilizing Murine Inducible Telomerase Alleles in the Studies of Tissue Degeneration/Regeneration and Cancer

Telomere dysfunction-induced loss of genome integrity and its associated DNA damage signaling and checkpoint responses are well-established drivers that cause tissue degeneration during ageing. Cancer, with incidence rates greatly increasing with age, is characterized by short telomere lengths and high telomerase activity. To study the roles of telomere dysfunction and telomerase reactivation in ageing and cancer, the protocol shows how to generate two murine inducible telomerase knock-in alleles 4-Hydroxytamoxifen (4-OHT)-inducible TERT-Estrogen Receptor (mTERT-ER) and Lox-Stopper-LoxTERT (LSL-mTERT). The protocol describes the procedures to induce telomere dysfunction and reactivate telomerase activity in mTERT-ER and LSL-mTERT mice in vivo. The representative data show that reactivation of telomerase activity can ameliorate the tissue degenerative phenotypes induced by telomere dysfunction. In order to determine the impact of telomerase reactivation on tumorigenesis, we generated prostate tumor model G4 PB-Cre4 PtenL/L p53L/L LSL-mTERTL/L and thymic T-cell lymphoma model G4 Atm-/- mTERTER/ER. The representative data show that telomerase reactivation in the backdrop of genomic instability induced by telomere dysfunction can greatly enhance tumorigenesis. The protocol also describes the procedures used to isolate neural stem cells (NSCs) from mTERT-ER and LSL-mTERT mice and reactivate telomerase activity in NSCs in vitro. The representative data show that reactivation of telomerase can enhance the self-renewal capability and neurogenesis in vitro. Finally, the protocol describes the procedures for performing telomere FISH (Fluorescence In Situ Hybridization) on both mouse FFPE (Formalin Fixed and Paraffin Embedded) brain tissues and metaphase chromosomes of cultured cells.

Telomere and telomerase play essential roles in ageing and tumorigenesis. The goal of this protocol is to show how to generate two murine inducible telomerase knock-in alleles and how to utilize them in the studies of tissue degeneration/regeneration and cancer.

Telomere dysfunction-induced loss of genome integrity and its associated DNA damage signaling and checkpoint responses are well-established drivers that ...

A Proinflammatory, Degenerative Organ Culture Model to Simulate Early-Stage Intervertebral Disc Disease.

Symptomatic intervertebral disc (IVD) degeneration (IDD) is a major socioeconomic burden and is characterized by inflammation and tissue degradation. Due to the lack of causative therapies, there is an urgent need for innovative experimental organ culture models to study the mechanisms involved in the progression of the disease, find therapeutic targets, and reduce the need for animal models. We here present a novel, three-dimensional organ culture model protocol mimicking the proinflammatory and catabolic microenvironment, which is present during IDD. 
Initially, bovine caudal IVDs were dissected, cleaned, and cultured in the tissue culture medium. Dynamic physiologic or pathologic loading was applied in a custom-made bioreactor for 2 hours per day. IVDs were assigned to a control group (high glucose medium, physiological loading, phosphate-buffered saline injection) and a pathological group (low glucose medium, pathological loading, tumor necrosis factor-alpha injection) for four days. Gene expression analysis from collected nucleus pulposus cells of the IVDs and enzyme-linked immunosorbent assay of the conditioned organ culture media was performed. 
Our data revealed a higher expression of inflammatory markers and reduced disc heights after loading in the pathological group compared to the control group. This protocol is reliable to simulate IVD inflammation and degeneration and can be further expanded to broaden its application scope.

This protocol presents a novel experimental model of proinflammatory, degenerative bovine organ culture to simulate early-stage intervertebral disc degeneration.

Symptomatic intervertebral disc (IVD) degeneration (IDD) is a major socioeconomic burden and is characterized by inflammation and tissue degradation. Due ...

Targeted Tuina Stimulation Protocol in Lumbar Region of IDD Model Rabbits

Operational and Intervention Effects of Targeted Tuina in Lumbar Intervertebral Disc Degeneration Model Rabbits

Tui Na or massage therapy alleviates symptoms related to intervertebral disc degeneration (IDD). However, precise, repeatable, standardized instructions for Tuina manipulation are lacking. This study establishes IDD model rabbits induced by fibrous ring puncture, creates targeted Tuina stimulation protocols at the acupuncture points in the lumbar region, and describes in detail the operation methods and requirements of kneading, pointing, and flicking. New Zealand male white rabbits (n = 15) were selected and randomly divided into a blank group, a model group, and a Tuina group. The rabbits in the model group and the Tuina group were molded by fibrous ring puncture; the rabbits in the model group were only immobilized on the operating table without treatment. In contrast, the Tuina group used the "8N/10N, 30 cycles/min" prescription for kneading, pointing, and flicking to perform the intervention, using tactile sensory aids to monitor and regulate the intensity of the Tuina operation. Imaging diagnosis and pathological tests were used to assess the effect of Tuina in rabbits, and the results showed improved imaging features and significantly lowered pathology scores of lumbar disc degeneration in the Tuina group compared to the model group (P &lt; 0.01). Targeted Tuina in the lumbar region may be beneficial in the alleviation of lumbar disc degeneration, but further verification is needed. By regularly performing Tuina and recording the mechanical information involved enables reproducible manipulation prescriptions and helps to observe the basic features of the underlying mechanism of Tuina for IDD.

The finger tactile measurement system quantifies tactile pressure on the finger using a highly sensitive electrosurgical pressure sensor, with software displaying and accurately recording the pressure data and video in real time. Two analysis modules unify the data processing for thumb tracking and conditioning during Tuina.

Tui Na or massage therapy alleviates symptoms related to intervertebral disc degeneration (IDD). However, precise, repeatable, standardized instructions ...

Induction of Lumbar Disc Degeneration in Rabbits Through a Transabdominal Approach

Lower back pain is an extremely common medical issue in populations worldwide. One of the main contributors to lower back pain is intervertebral disc (IVD) degeneration. An ideal animal model of IVD degeneration is essential to study the pathophysiology of lower back pain and investigate potential therapeutic strategies. Rabbit models are reliable, economical, and easily established animal models. The retroperitoneal approach has been widely used to induce IVD degeneration in rabbit models. However, there are reported complications associated with this technique, such as the avulsion of segmental arteries and nerve root injury. In this paper, we aim to show a surgical protocol using needle puncture to establish rabbit lumbar disc degeneration via a transabdominal approach. Consequently, radiological checks and histological analyses indicated that lumbar disc degeneration was successfully established in rabbits. This surgical protocol presents the precise location of target discs and high reproducibility of IVD degeneration models with fewer complications.

Here, we describe a surgical protocol using needle puncture to establish rabbit lumbar disc degeneration via a transabdominal approach. Radiological checks and histological analyses were used to confirm the successful establishment of lumbar disc degeneration.

Lower back pain is an extremely common medical issue in populations worldwide. One of the main contributors to lower back pain is intervertebral disc ...

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.

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 ...

Biology

Optical Sectioning and Visualization of the Intervertebral Disc from Embryonic Development to Degeneration

Intervertebral disc (IVD) degeneration is a leading cause of low back pain and it entails a high degree of impairment for the affected individuals. To decode disc degeneration and to be able to develop regenerative approaches a thorough understanding of the cellular biology of the IVD is essential. One aspect of this biology that still remains unanswered is the question of how cells are spatially arranged in a physiological state and during degeneration. The biological properties of the IVD and its availability make this tissue difficult to analyze. The present study investigates spatial chondrocyte organization in the anulus fibrosus from early embryonic development to end-stage degeneration. An optical sectioning method (Apotome) is applied to perform high resolution staining analyses using bovine embryonic tissue as an animal model and human disc tissue obtained from patients undergoing spine surgery. From a very high chondrocyte density in the early embryonic bovine disc, the number of cells decreases during gestation, growth, and maturation. In human discs, an increase in cellular density accompanied the progression of tissue degeneration. As had already been demonstrated in articular cartilage, cluster formation represents a characteristic feature of advanced disc degeneration.

We present a method to investigate spatial chondrocyte organization in the anulus fibrosus of the intervertebral disc using an optical sectioning method.

Intervertebral disc (IVD) degeneration is a leading cause of low back pain and it entails a high degree of impairment for the affected individuals. To ...

Comparing Transperitoneal Retroperitoneal Access and Percutaneous Puncture for Lumbar Disc Degeneration Modeling in Rabbits

This study compares the efficacy of two methods for inducing intervertebral disc degeneration (IVDD) in rabbits: percutaneous and trans-retroperitoneal puncture of the annulus fibrosus. Fifteen healthy male New Zealand White rabbits were randomly assigned to three groups: sham, percutaneous puncture, and trans-retroperitoneal puncture. A comprehensive assessment, including mortality rates, morphological and histological evaluations, radiological imaging, and biomarker analysis, was conducted to ensure an accurate and detailed comparison between the two methods. The results demonstrate that both puncture techniques successfully induced IVDD in the rabbit model. However, the trans-retroperitoneal approach resulted in more pronounced degenerative changes in the intervertebral discs while maintaining a significantly lower mortality rate compared to the percutaneous method. These findings highlight the advantages of the trans-retroperitoneal approach in IVDD modeling. This study provides valuable insights into the establishment of IVDD models and lays a foundation for future investigations into effective treatment strategies for low back pain, ultimately improving patient outcomes.

This protocol compared percutaneous and trans-retroperitoneal punctures in a rabbit intervertebral disc degeneration (IVDD) model. Both methods induced IVDD; however, the trans-retroperitoneal approach resulted in more extensive changes and lower mortality.

This study compares the efficacy of two methods for inducing intervertebral disc degeneration (IVDD) in rabbits: percutaneous and trans-retroperitoneal ...

Generating a Pro-Inflammatory Organ Culture Model to Simulate an Early Intervertebral Disc Disease

Source: Saravi, B., et al. <a href="https://app.jove.com/v/62100">A Proinflammatory, Degenerative Organ Culture Model to Simulate Early-Stage Intervertebral Disc Disease.</a> J. Vis. Exp. (2021).
This video demonstrates a technique for culturing bovine intervertebral discs in bioreactors to develop a three-dimensional organ culture model. Specific nutrient-deprived media and degenerative pressure conditions are applied to the discs, mimicking the pro-inflammatory and degenerative microenvironment observed during early-stage intervertebral disc disease. The disc heights are measured post-treatment to analyze the effects of nutrient deprivation and degenerative loading.

All procedures involving animal samples have been reviewed and approved by the appropriate animal ethical review committee.
1. Dissection of the bovine ...

Ovine Lumbar Intervertebral Disc Degeneration Model Utilizing a Lateral Retroperitoneal Drill Bit Injury

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