Mechanical and Pathologic Consequences of Induced Concentric Anular Tears in an Ovine Model

Fazzalari, Nicola L.; Costi, John J.; Hearn, Trevor C.; Fraser, Robert D.; Vernon‐Roberts, B.; Hutchinson, J.; Manthey, Beverley A.; Parkinson, Ian H.; Sinclair, Case C.

doi:10.1097/00007632-200112010-00010

Cited by 85 publications

(69 citation statements)

References 27 publications

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“…Large animal models reduce the size discrepancy, but most still require artificial induction for degeneration, including dog, sheep, and pig. 4,29,33,35 Compared to humans, these animals have similar biology; however, their quadrupedal biomechanical loading of the disc does not accurately represent the human condition.…”

Section: Discussionmentioning

confidence: 99%

“…[13][14][15][16] The altered biomechanical response of degenerate disc tissues have been measured. [2][3][4][17][18][19][20][21][22][23][24] Disc stiffness decreases with low-grade degeneration and increases with the most severe degeneration, while energy absorption decreases throughout degeneration. Further, spinal segment range of motion and neutral zone increase with advancing degeneration up to the most severely degenerated discs, where these properties reverse course with increasing stiffness.…”

mentioning

confidence: 99%

“…Lumbar intervertebral discs change morphologically, biochemically, and biomechanically with advancing age, [1][2][3][4][5][6][7][8][9][10] changes that are characterized as disc degeneration and are implicated as the origin of low back pain. Unfortunately, the initiating and perpetuating factors of disc degeneration are unknown, so despite the pain, disability, and economic loss associated with disc degeneration, intervention and mitigation strategies cannot effectively proceed.…”

mentioning

confidence: 99%

“…28,29 Animal models can clarify pathomechanisms and aid in development of therapeutic strategies. While most animal models require mechanical or chemical induction, 4,[29][30][31][32][33][34][35][36][37][38] the macaque has naturally degenerating intervertebral discs (Fig. 1).…”

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confidence: 99%

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Intervertebral disc degeneration in a naturally occurring primate model: Radiographic and biomechanical evidence

Nuckley

Kramer

Rosario

et al. 2008

Journal Orthopaedic Research

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Classic degenerative disc disease is a serious health problem worldwide, whose etiological basis-mechanical stimulus, biochemical changes, or natural aging-is poorly understood. Animal models are critical to the study of degenerative disc disease initiation and progression and for attempts to regulate, ameliorate, or eliminate it. The macaque represents a primate model with natural disc degeneration that might serve to advance the field; we aimed to provide radiographic (morphologic) and biomechanical evidence of natural disc degeneration in this model. A factorial study design was used to examine the relationship between the radiographic appearance of disc degeneration and its biomechanical consequences. Eighteen macaques of advanced age (22.3 AE 0.9 years) had radiographs taken to assess the degree of thoracolumbar intervertebral disc degeneration using a standard atlas method. Each spine was harvested and dynamic biomechanical tests were performed. Advancing disc degeneration (degree of disc space narrowing and osteophytosis) was associated with increased stiffness, decreased energy absorption, and increased natural frequency of the intervertebral disc. These associations linking the dynamics of the intervertebral disc and its degree of degeneration are similar to those found in humans. Our results indicate the macaque model with morphologic and biomechanical efficacy could aid in understanding the progression of disc degeneration and in developing therapeutic strategies to prevent or inhibit its course. Keywords: intervertebral disc; disc degeneration; Macaca fascicularis; disc dynamics; biomechanics Lumbar intervertebral discs change morphologically, biochemically, and biomechanically with advancing age, 1-10 changes that are characterized as disc degeneration and are implicated as the origin of low back pain. Unfortunately, the initiating and perpetuating factors of disc degeneration are unknown, so despite the pain, disability, and economic loss associated with disc degeneration, intervention and mitigation strategies cannot effectively proceed. Morphologically, dehydration and diminished cellularity of the nucleus pulposus and disorganization and lesions of the annulus fibrosus demarcate disc degeneration. These changes manifest as decreased disc height, increased radial bulging, and osteophyte formation. 11,12 Morphologic changes are intrinsically tied to the biochemistry and biomechanics of the system, and visible and radiographic changes are used to define gradations of disc degeneration. [13][14][15][16] The altered biomechanical response of degenerate disc tissues have been measured. [2][3][4][17][18][19][20][21][22][23][24] Disc stiffness decreases with low-grade degeneration and increases with the most severe degeneration, while energy absorption decreases throughout degeneration. Further, spinal segment range of motion and neutral zone increase with advancing degeneration up to the most severely degenerated discs, where these properties reverse course with increasing stiffness. Unfortun...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Intervertebral disc degeneration in a naturally occurring primate model: Radiographic and biomechanical evidence

Nuckley

Kramer

Rosario

et al. 2008

Journal Orthopaedic Research

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“…[13][14][15][16][17] It is generally believed that needle puncture injury with small-gauge needles is not expected to cause damage, whereas needle puncture injury with large-gauge needles leads to degenerative changes. AF needle puncture injury to the disc in rabbits using needles of different gauges has been demonstrated to result in slow progressive degeneration as measured using magnetic resonance imaging (MRI), radiograph, histology, and polymerase chain reaction.…”

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confidence: 99%

Needle Puncture Injury Affects Intervertebral Disc Mechanics and Biology in an Organ Culture Model

Korecki¹,

Costi²,

Iatridis³

2008

Spine

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133

114

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Study Design-A bovine intervertebral disc organ culture model was used to study the effect of needle puncture injury on short-term disc mechanics and biology.Objective-To test the hypothesis that significant changes in intervertebral disc structure, mechanics, and cellular response would be present within 1 week of needle puncture injury with a large-gauge needle but not with a small-gauge needle.Summary of Background Data-Defects in anulus fibrosus induced by needle puncture injury can compromise mechanical integrity of the disc and lead to degeneration in animal models. The immediate and short-term mechanical and biologic response to anulus injury through needle puncture in a large animal model is not known.Methods-Bovine caudal intervertebral discs were harvested, punctured posterolaterally using 25G and 14G needles, and placed in organ culture for 6 days. Discs underwent a daily dynamic compression loading protocol for 5 days from 0.2 to 1 MPa at 1 Hz for 1 hour. Disc structure and function were assessed with measurements of dynamic modulus, creep, height loss, water content, proteoglycan loss to the culture medium, cell viability, and histology.Results-Needle puncture injury caused a rapid decrease in dynamic modulus and increase in creep during 1-hour loading, although no changes were detected in water content, disc height, or proteoglycan lost to the media. Cell viability was maintained except for localized cell death at the needle insertion site. An increase in cell number and possible remodeling response was seen in the insertion site in the nucleus pulposus.Conclusion-Relatively minor disruption in the disc from needle puncture injury had immediate and progressive mechanical and biologic consequences with important implications for the use of discography, and repair-regeneration techniques. Results also suggest diagnostic techniques sensitive to mechanical changes in the disc may be important for early detection of degenerative changes in response to anulus injury. Keywordsspine; intervertebral disc; organ culture; needle puncture; bovine; discography; mechanics; dynamic compression loading ©2008, Lippincott Williams & WilkinsAddress correspondence and reprint requests to James C. Iatridis, PhD, 201 Votey Building, 33 Colchester Avenue, Burlington, VT, 05405; E-mail: E-mail: james.iatridis@uvm.edu. NIH Public AccessAuthor Manuscript Spine (Phila Pa 1976 Current and future procedures for intervertebral disc (IVD) diagnosis, repair, and regeneration often require needle injection to the nucleus pulposus (NP) through the anulus fibrosus (AF). For example, discography, which requires injection of a radio opaque dye into the NP, has a best-case positive predictive value of 50% to 60%, and results in potential AF damage through needle puncture. 4 Intradiscal electrothermal treatment also requires puncture of the AF and additional anular disruption using a catheter. 5 Future treatments including growth factor therapy, 6 tissue engineering, 7 and gene and cell therapy 8,9 may also require puncture of t...

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Injectable, high‐density collagen gels for annulus fibrosus repair: Anin vitrorat tail model

Borde

Grunert

Härtl

et al. 2014

J Biomedical Materials Res

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A herniated intervertebral disc often causes back pain when disc tissue is displaced through a damaged annulus fibrosus. Currently the only methods available for annulus fibrosus repair involve mechanical closure of defect, which does little to address biological healing in the damaged tissue. Collagen hydrogels are injectable and have been used to repair annulus defects in vivo. In this study, high-density collagen hydrogels at 5, 10 and 15 mg/ml were used to repair defects made to intact rat caudal intervertebral discs in vitro. A group of gels at 15 mg/ml were also crosslinked with riboflavin at 0.03 mM, 0.07 mM or 0.10 mM . These crosslinked, high-density collagen gels maintained presence in the defect under loading and contributed positively to the mechanical response of damaged discs. Discs exhibited increases to 95% of undamaged effective equilibrium and instantaneous moduli as well as up to four fold decreases in effective hydraulic permeability from the damaged discs. These data suggest that high density collagen gels may be effective at restoring mechanical function of injured discs as well as potential vehicles for delivery of biological agents such as cells or growth factors that may aid in the repair of the annulus fibrosus.

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Mechanical and Pathologic Consequences of Induced Concentric Anular Tears in an Ovine Model

Abstract: Concentric tears and needlestick injury in the anterior anulus lead to mechanical changes in the disc and both anular lamellar thickness and vertebral body bone volume fraction. A needlestick injury through the anulus parallel to the lamellae produces progressive damage.

Cited by 85 publications

References 27 publications

Intervertebral disc degeneration in a naturally occurring primate model: Radiographic and biomechanical evidence

Intervertebral disc degeneration in a naturally occurring primate model: Radiographic and biomechanical evidence

Needle Puncture Injury Affects Intervertebral Disc Mechanics and Biology in an Organ Culture Model

Injectable, high‐density collagen gels for annulus fibrosus repair: Anin vitrorat tail model

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