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At least 883 records · Page 49Linked to original sources
PubMed1980

A morphological and histological study of the postnatal development of intervertebral discs in the lumbar spine of the rabbit.

Some basic features in the development of the structure of the annulus fibrosus and nucleus pulposus in the rabbit, as described by previous workers, have been confirmed in the present study. However, the greater thickness of the anterior part of the disc, as compared with the posterior region, and the distinctive arrangement of lamellae in the posterior part of the disc, cannot be attributed, as conventionally claimed from studies of the human spine, to a secondary curvature in the lumbar spine associated with an upright posture: for these features are present in the lumbar spine of the quadrupedal rabbit with its primary curvature. Secondary ossification produces a plate-like epiphysis separating the growth cartilage from the intervertebral disc. A distinct cartilaginous plate, limiting the nucleus pulposus in the rabbit intervertebral disc, only becomes apparent when collagen fibres cease to traverse the area above and below the nucleus pulposus.

Animals↗
PubMed2002

Acute intervertebral disc extrusion in a cat: clinical and MRI findings.

A 5 year old, neutered male, domestic shorthaired cat had acute left hemiparesis and Horner's syndrome. Magnetic resonance imaging (MRI) revealed a loss of the normal signal from the nucleus pulposus of the intervertebral disc at C3/4, narrowing of the ventral subarachnoid space and slight dorsal displacement of the spinal cord and a focal hyperintense lesion affecting the left side of the spinal cord at the same level. The presumptive diagnosis was focal spinal cord oedema associated with intervertebral disc extrusion. A traumatic aetiology was suspected. The cat was treated conservatively and improved gradually over a period of 6 months.

Animals↗
PubMed2001

Replacing the nucleus pulposus of the intervertebral disc.

OBJECTIVE: To determine whether replacement of the nucleus with a synthetic material would prevent the effects of nucleus removal. DESIGN: Laboratory experiments on excised tissues and a finite element model. BACKGROUND: Removal of the nucleus from the intervertebral disc causes the inner margins of the annulus to bulge inwards, instead of outwards, during compression. This may cause the annulus to degenerate further. METHODS: Video recordings of sheep discs, sectioned in the sagittal plane, were obtained during compression in a materials testing machine; the cut face of the disc was sealed with a Perspex window. Experiments were repeated with the nucleus removed and then replaced by a synthetic implant. A finite element model of an intact disc was also used to investigate the effect of nucleus replacement. RESULTS: When the nucleus of sectioned discs was replaced with the polymer materials, the inward bulging of the annulus was not observed. The predictions from the finite element model of the intact disc were consistent with this result. CONCLUSIONS: Replacement of the nucleus with a synthetic material can prevent the changes in annulus behaviour that result from removal of the nucleus. RELEVANCE: A suitable implant to replace the nucleus after surgical removal may help prevent inward bulging of the inner layers of the annulus.

Animals↗
PubMed2003

A fibronectin fragment stimulates intervertebral disc degeneration in vivo.

STUDY DESIGN: A radiographic, histologic, biochemical, and gene expression study was conducted in vivo in a rabbit model to determine the effect of injection of the N-terminal 30 kDa fibronectin fragment (Fn-f) into the intervertebral disc along with various control substances. OBJECTIVE: To determine if the Fn-f is able to induce disc degeneration in vivo. SUMMARY OF BACKGROUND DATA: Animal models of disc degeneration are crucial to defining the molecular events involved in disc degeneration. Although spontaneous and induced models of disc degeneration have been described, none is ideal for molecular studies. A better understanding of disc degeneration at the molecular level is necessary to promote rational design of therapies for degenerative disc disease. MATERIALS AND METHODS: Thirty-one New Zealand white rabbits underwent injection of Fn-f and control substances into the central region of separate lumbar discs using a fine needle. Euthanasia was performed at the 2-, 4-, 8-, 12-, and 16-week time points and the discs were examined radiographically, histologically, biochemically, and with gene expression. RESULTS: Radiographs demonstrated anterior osteophyte formation at Fn-f-injected disc spaces by the 12-week time point. Histology demonstrated a progressive loss of the normal architecture of the nucleus pulposus and anulus fibrosus over the 16-week study period. A progressive loss of proteoglycans was documented using GAG assay but total collagen did not appear to change appreciably. Gene expression studies demonstrated a significant down-regulation of both aggrecan and type II collagen mRNA between the 8- and 16-week time points. CONCLUSION: Fn-f appears to induce a progressive degenerative process within the intervertebral disc after injection that resembles degenerative disc disease. This model has several significant advantages for the study of disc degeneration at the molecular level. Further studies are warranted to elucidate the mechanism and molecular events associated with Fn-f-mediated disc degeneration.

Aggrecans↗
PubMed1976

The collagenous and non-collagenous protein of the canine intervertebral disc and their variation with age, spinal level and breed.

The total nitrogen, collagen and non-collagenous protein (NCP) content of the nucleus pulposus (NP), transitional zone (TZ) and annulus fibrosus (AF) of the beagle (a chondrodystrophoid breed) and greyhound (a non-chondrodystrophoid breed) intervertebral discs have been determined over the age range birth to 124 months. Discs were sampled at three spinal levels - lumbosacral, lumbar and thoracic regions. The beagle NP attains an average NP collagen content of 25% dry weight before 11 months of age, whereas the greyhound NP content is less than 5% collagen for most of its life. The NCP of the young greyhound disc is greater than that of the beagle of corresponding age. Plots of the ratio of collagen/NCP for discal regions at various ages highlight the large differences between the two breeds of dog. It is suggested that these differences in protein distribution are related to the elevated incidence of intervertebral disc prolapse in the beagle.

Aging↗
PubMed2005

The pathogenesis and clinical significance of a high-intensity zone (HIZ) of lumbar intervertebral disc on MR imaging in the patient with discogenic low back pain.

Recently, the presence of a high-intensity zone (HIZ) within the posterior annulus seen on T2-weighted MRI has aroused great interest and even controversy among many investigators, particularly on whether the HIZ was closely associated with a concordant pain response on awake discography. The study attempted to interpret the correlation between the presence of the HIZ on MRI and awake discography, as well as its characteristic pathology. Fifty two patients with low back pain without disc herniation underwent MRI and discography successively. Each disc with HIZ was correlated for an association between the presence of a HIZ and the grading of annular disruption and a concordant pain response. Eleven specimens of lumbar intervertebral discs which contain HIZ in the posterior annulus from 11 patients with discogenic low back pain were harvested for histologic examination to interpret the histologic basis of a nociceptive response during posterior lumbar interbody fusion (PLIF). The study found that in all of 142 discograms in 52 patients, 17 presented HIZ. All 17 discs with HIZ showed painful reproduction and abnormal morphology with annular tears extending either well into or through the outer third of the annulus fibrosus. The consecutive sagittal slices through the HIZ lesion showed that a notable histologic feature of the formation of vascularized granulation tissue in the outer region of the annulus fibrosus. The current study suggests that the HIZ of the lumbar disc on MRI in the patient with low back pain could be considered as a reliable marker of painful outer anular disruption.

Adolescent↗
PubMed1991

[Vacuum phenomenon in the intervertebral disc].

Author observed two cases of vacuum phenomenon (pneumatic shadow) in the intervertebral disc. Out of a detailed description of the patients the diagnostic significance of the X-ray sign is discussed.

Adult↗
PubMed1998

Experimental factors governing the internal stress state of the intervertebral disc.

This paper presents an experimental study of the response of the intervertebral disc to short-term static-axial loading within the conceptual framework of mechanical consolidation as applied to swelling materials. An experimental technique developed previously for articular cartilage was used to load the disc in compression and measure simultaneously the matrix internal excess pore pressure under both radially constrained and radially unconstrained conditions. Specifically the short-term pattern of development of the hydrostatic excess pore pressure was investigated. The average ratio of the maximum excess pore pressure u(i) to the nominal applied stress for unconstrained loading was approximately 1.9 while for constrained loading it was about 1.4. This behaviour is interpreted in terms of the generation of a pore pressure in the nucleus which reflects a non-uniform partitioning of the applied load across the inhomogeneous structure of the disc. These results provide a quantitative insight into the role that physico-chemically generated swelling plays in determining the internal mechanical response of the disc to an externally applied load and suggest a quantitative means of investigating the important influence of degenerative changes on the internal stress state of the disc without needing to pierce the annular wall in order to insert a pressure sensing device.

Animals↗
PubMed1991

Calcification of intervertebral discs in the dachshund. A radiographic study of 327 young dogs.

The vertebral columns of 327 clinically normal, 12 to 18 months old dachshunds, were x-rayed. This sample represented 16.1% of all dachshunds registered with the Norwegian Kennel Club in the period 1986-1988. Calcified intervertebral discs were identified in 79 (24.2%) of the dogs and the number of calcified discs in each individual varied from 1 to 11 with a mean of 2.3. Calcified discs were estimated to occur in 23.5% of Norwegian dachshunds. The occurrence of calcified discs in standard-sized dachshunds was higher in the wirehaired variety (27.1%) than in the smoothcoated (16.4%) or longhaired (9.1%) varieties. However, within the longhaired variety the occurrence was higher in dwarfs and kaninchens (36.0%) than in standard-sized dachshunds (9.1%). Calcification was identified in all cervical, thoracic and lumbar intervertebral discs other than T1-2, and was found to be most frequent in the caudal thoracic vertebral column.

Animals↗
PubMed2004

[Experiences with six different intervertebral disc spacers for spondylodesis of the cervical spine].

Spondylodesis of the cervical spine with autologous bone in cases of degenerative disease is associated with pain and complications in the os ilium region. Can this problem be solved when using intervertebral disc spacers? Between September 1997 and January 2003, 267 patients with degenerative disease of the cervical spine were treated operatively and monitored in a follow-up examination. In osteochondrosis of the cervical spine and/or disc herniation, we performed a discectomy using a ventral approach and removed dorsal osteophytes with a high-speed drill. The choice of the six different spacers was randomized. We used 66 titanium disc spacers manufactured by Aesculap, 54 titanium disc spacers by Weber, 52 titanium disc spacers by Intromed, 18 Wing spacers by Medinorm, 17 carbonium spacers by AcroMed, and 50 PEEK spacers by Intromed and did follow-up examinations after 3 and 12 months, respectively. The titanium spacer manufactured by Weber is characterized by good handling and a moderate price. The titanium cage from Intromed has the lowest price and good handling characteristics during operation. The X-ray contrast of the carbonium spacer made by AcroMed is not always sufficient for safe implantation, especially in the lower cervical spine. Handling is good, but the price is too high. The AcoMed, Medinorm, and Intromed titanium spacers show a tendency for penetrating ground plates of adjacent vertebra. The titanium cage Cespace manufactured by Aesculap has good handling characteristics and a moderate price. The PEEK spacer from Intromed can be implanted safely but shows a tendency for dislocation. Long-term results are yet to be reported.

Adult↗
PubMed2002

Current understanding of cellular and molecular events in intervertebral disc degeneration: implications for therapy.

Until recently, material removed from the intervertebral disc (IVD) at surgery consisted either of 'loose bodies' from the centre of the IVD or discal tissue displaced (prolapsed) into the intervertebral root or spinal canals. This material is best regarded as a by-product of disc degeneration and therefore not representative of the disease process itself. Recent advances in surgical techniques, particularly anterior fusion, in which large segments of the anterior part of the IVD are excised with the anatomical relationships between different components intact, have generated material that can be investigated with modern molecular and cell biological techniques. This is an important area of study because degeneration of the lumbar IVDs is associated, perhaps causally, with low back pain, one of the most common and debilitating conditions in the West. 'Degeneration' carries implications of inevitable progression of wear-and-tear associated conditions. Modern research on human IVD tissue has shown that this is far from the case and that disruption of the micro-anatomy described as degeneration is an active process, regulated by locally produced molecules. The exciting consequence of this observation is the possibility of being able to inhibit or even reverse the processes of degeneration using targeted therapy.

Cytokines↗
PubMed2001

Regulation of gelatinase-A (MMP-2) production by ovine intervertebral disc nucleus pulposus cells grown in alginate bead culture by Transforming Growth Factor-beta(1)and insulin like growth factor-I.

The aim of this study was to gain information relevant to disc repair processes. Limited degradation of the collagen matrix by matrix metalloproteases (MMPs) may facilitate the loosening of cell-cell and cell-matrix interactions within the injured intervertebral disc (IVD) to favour the penetration of blood vessels and migration of fibroblasts into the defect to promote repair processes. Gelatinase A (MMP-2) has a particularly important role to play in angiogenesis, in the present study we investigated the in vitro regulation of MMP-2 by Transforming Growth Factor-beta 1 (TGF-beta 1) and Insulin-like Growth Factor-1 (beta IGF-I) in cells from the nucleus pulposus (NP) of the ovine IVD. Ovine NP cells were grown in alginate bead cultures in complete medium (10% foetal calf serum) for 7 days, established in serum-free conditions for 24 h, then stimulated with TGF-beta 1 (0.1 or 10 ng/ml) or IGF-I (2 or 50 ng/ml) +/-Concanavalin A (20 microg/ml) for an additional 48 h. Conditioned medium was examined for matrix metalloproteases using gelatin zymography, Tissue Inhibitor of Metalloproteinase 2 (TIMP-2) and Membrane Type 1 Matrix Metalloproteinase (MT1-MMP) were immunolocalised in beads. Pro (72 kDa) and active (59 kDa) MMP-2 were the major gelatinolytic MMPs detected in control cultures, the TGF-beta 1 and IGF-I treatments significantly decreased levels of the active MMP-2, inclusion of Concanavalin A resulted in a complete reversal of this trend with IGF-I, and to a lesser extent with TGF-beta 1. Cell surface levels of TIMP-2 and MT1-MMP were decreased by the TGF-beta 1 treatment while IGF-I only appeared to decrease TIMP-2 expression. The findings of this study provide some insight as to why dense avascular connective tissues such as the intervertebral disc have such a poor healing potential.

Alginates↗
PubMed1959

Stretching of the sciatic nerve; a means of relieving postoperative pain following removal of ruptured lumbar intervertebral discs.

Stretching the sciatic nerve for the relief of "sciatica" was frequently employed before 1900 and was subsequently abandoned, probably because it was done without sufficient scrutiny of the indications. The procedure has recently been employed in cases in which "sciatica" remains following the operative removal of ruptured intervertebral discs, and it has been instrumental in relieving postoperative "sciatica" when the cause was the formation of adhesions about the lumbar nerve roots. If the nerve root is compressed by recurrent disc protrusion or by adjacent bone, the manipulation usually increases the pain, a phenomenon that has been helpful from a diagnostic standpoint.

Exercise Therapy↗
PubMed1991

Design of an intervertebral disc prosthesis.

This article presents criteria for the design of a lumbar intervertebral disc prosthesis that take into consideration issues of endurance, materials behavior, geometry, kinetics, motion constraints, fixation to bone, and safety. The criteria and design philosophies discussed are generally applicable in the synthesis of any new implant system. Specifications of the design of a disc prosthesis are presented along with an evaluation of the design based on some of the preliminary test data.

Chromium Alloys↗
PubMed1988

[A biomechanical study of the lumbar intervertebral disc by the finite element method].

The biomechanical characteristics of the lumbar intervertebral disc were investigated by 3-dimensional finite element method. The results were: (1) Under compression load, the nucleus pulposus received the strongest vertical force and the annulus fibrosus restrained its expansion. The inner posterolateral annulus fibrosus was vulnerable. (2) Under flexion load, some posterior shifting of the nucleus pulposus occurred, along with the decrease of posterior bulging and the increase of anterior bulging. The outer anterior and inner posterior annulus fibrosus were vulnerable. (3) Under either compression or flexion load, the increase in the nucleus pressure ratio (PN/Pa) for the same disc attained almost the same value. (4) At the nucleus area ratio of 37.5%, the maximum compressive stiffness value occurred. (5) PN/Pa decreased with the increase of the nucleus area ratio but increased as disc narrowing advanced. (6) When the nucleus pulposus lost its hydrostatic property, the compressive stiffness value decreased to 43%, the potential damage could encompass the entire annulus fibrosus.

Biomechanical Phenomena↗