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At least 919 records · Page 51Linked to original sources
PubMed1994

Anular incision technique on the strength and multidirectional flexibility of the healing intervertebral disc.

STUDY DESIGN: This study used a sheep model to biomechanically analyze the healing strength of the anulus fibrosus after two types of anular incisions. OBJECTIVE: This study evaluated whether the type of anular incision made at the time of lumbar discectomy plays a role in the subsequent healing strength of the anulus and the biomechanical flexibility of the corresponding motion segment. METHODS: Two types of anular incision, a full thickness removal of a box or window of anulus and a full thickness straight transverse slit through the anulus, were made in the intervertebral discs of 18 adult sheep. After healing times of 2, 4, and 6 weeks, the intervertebral discs were tested versus control levels for strength of anular healing and biomechanical flexibility of the corresponding motion segment. RESULTS: The box incised discs showed a significantly greater loss in strength during the early healing phase (2 to 4 weeks) and a longer response before recovering anular strength when compared with the slit-incised discs. The type of incision also affected the multidirectional flexibility of the motion segments in a differentiated manner. Larger amounts of motion were seen with the box incision when compared with the slit incision at all time periods and in all pure moments. CONCLUSION: The technique of anular incision plays a definite role in the timing and strength of subsequent anular healing. The box incision through the anulus led to significantly weaker healing than did the slit incision in the early healing phase (2-4 weeks). Also, larger amounts of motion were seen in the vertebral motion segments of those discs undergoing box incision when compared with slit or control levels.

Animals↗
PubMed1975

Extreme lateral ruptures of lumbar intervertebral discs.

Several cases are presented of extreme lateral rupture of the lumbar intervertebral disc in which symptoms of localized nerve root compression were not manifest and in which myelography was negative or misleading. Ordinary exploration techniques failed to disclose these lesions. The most striking pain patterns seen in these patients were flank pain, gluteal, groin, and sometimes upper anterior thigh pain, induced or aggravated by back motion. This pain, plus radiating leg pain, when it occurred, was generally exceedingly severe and disproportionate to the neurological deficit. Lumbar discography was useful in detecting these ruptures.

Adult↗
PubMedDate not supplied

In vitro measurement of pressure in intervertebral discs and annulus fibrosus with and without annular tears during discography.

BACKGROUND CONTEXT: Discogram studies have shown that pain reproduction correlates with the extent of annular disruption. However, it has not been assessed if pressure changes in the annulus fibrosus vary incrementally with intradiscal pressure. PURPOSE: To determine the relationship between intradiscal pressure and outer annular pressure during discography in intervertebral discs with and without annular tears. STUDY DESIGN: Intradiscal and periannular pressures were measured simultaneously in vitro during intradiscal injection in porcine cadaver spines. METHODS: Twenty fresh porcine cadaver lumbar spines with intervening discs were tested. Intradiscal and periannular pressures were measured simultaneously using two pressure sensors during intradiscal contrast injection. The tip of a 25-gauge needle connected with a pressure manometer was placed in the center of the nucleus pulposus. A second pressure transducer was located at the outer third of the annulus fibrosus. Needle and transducer locations were confirmed by fluoroscopy. To compare the intact and torn annulus fibrosus, annular disruptions were created with a 20-gauge needle and confirmed by fluoroscopy. RESULTS: During intradiscal injections of discs with an intact annulus, annulus fibrosus pressure remained low and a sharp increase in intradiscal pressure was observed. Significantly higher pressures were noted in the outer annulus in discs with annular tears (p<.01). Mean pressures at the central nucleus pulposus, the outer third of intact annuli and torn annuli were 93.4+/-40.9 psi, 14.8+/-1.9 psi and 85.7+/-24.8 psi, respectively. CONCLUSIONS: Volumetric injection of intervertebral discs with a torn annulus fibrosis during discography may increase intra-annular pressure similar to the increase in pressure that may occur during spinal loading activities. This effect may not occur in discs with an intact annulus fibrosus.

Animals↗
PubMed1990

[Influence of finger pressing massage on cAMP and cGMP in the cerebrospinal fluid in prolapsed intervertebral disc].

This paper used RIA method to observe 11 cases of prolapsed intervertebral disc patients, detect the change of cAMP and cGMP in the cerebrospinal fluid before and after finger pressing massage in acupuncture point Weizhong and Chengshan in order to discuss the mechanism of analgesia of finger pressing massage. The results showed that the pain was relieved after finger pressing massage. cAMP of the cerebrospinal fluid increased from 0.51 +/- 0.19 to 0.63 +/- 0.13 pm/ml, in average 32% higher than that before the therapy (P less than 0.05). Since cGMP decreased from 30.52 +/- 26.42 to 23.20 +/- 16.91 pm/ml, it showed that the mechanism of analgesia of finger pressing massage might be due to the fact that the therapy excited selectively endogenous analgesia system, caused the increase of endorphin releasing, and was accompanied by the regulation of cAMP and cGMP.

Acupuncture Points↗
PubMed2002

The influence of intervertebral disc tissue on anterior spinal interbody fusion: an experimental study on pigs.

Intervertebral disc has been shown to be related to low back pain and nerve root injury in pathologic conditions. However, little is known about its influence on spinal fusion. With the development of minimal invasive operations, such as laparoscopic anterior spinal fusion with cages, insufficient discectomy may occur. With its inflammatory properties, the residue nucleus pulposus may have an effect on spinal fusion. In this study, a two-level lumbar spine interbody fusion (L3/4, L5/6) with a Brantigan cage was performed on ten Danish Landrace pigs. Each level was randomly assigned to one of the following methods: (1) implantation of Brantigan cage filled with autogenous iliac crest bone graft, or (2) implantation of Brantigan cage filled with a mixture of autograft and the nucleus pulposus tissue harvested from the disc level in which it was to be inserted. Each level was stabilized with two staples. The pigs were followed for 12 weeks in the same standardized condition. After sacrifice, the lumbar spines were taken out, and plain X-ray, computed tomographic (CT) scanning and histomorphometry were performed to study the fusion mass inside the cages. From plain radiographs, new bone formation could be seen inside and around the cage. CT evaluation showed that the nucleus pulposus level had a 20% (2/10) fusion rate, while the pure autograft level had a 70% (7/10) fusion rate ( P=0.07). The histological fusion rate was even lower in the nucleus pulposus level (10%), and was significantly different from the autograft level (70%, P=0.02). Histomorphometric parameters of new bone formation, bone marrow space and fibrous tissue differed significantly between the two levels ( P=0.04; P=0.02; P=0.04 respectively). We conclude that when nucleus pulposus is mixed with the autogenous bone graft, it can delay or decrease the bone formation inside the cage, thus influencing the final fusion.

Animals↗
PubMedDate not supplied

Investigations of fluorescent peptides and lipofuscins of human intervertebral disc relating to atherosclerosis.

(1) Annulus fibrosus and nucleus pulposus of human intervertebral discs at different degrees of atherosclerosis were disintegrated by elastase. (2) The material disintegrated by elastase -- called elastolysate -- could be separated into hydrophobic (apolar) and hydrophilic (polar) peptides. Parallel with the degree of atherosclerosis the amount of hydrophobic peptides increased, whereas that of the hydrophilic peptides decreased. (3) In annulus fibrosus and nucleus pulposus two kinds of fluorescence maxima were measured. The one, A:F 350:405, is known as fluorescence maxima of elastin- and collagen-peptides. The other, A:F 410:470, is related to a similar substance called atherofluorescent component (AFC), which has been isolated before from the plaques of atherosclerotic aorta. This substance accumulates mainly in nucleus pulposus and resembles lipofuscin-like bodies. (4) These bodies show a positive reaction with thiobarbituric acid, giving a red coloration characteristic for malondialdehyde. In nucleus pulposus the amount of lipofuscin-like substances is much greater than in annulus fibrosus. (5) The hydrophilic peptides, although they show the same fluorescence maxima as the hydrophobic peptides, do not give any reaction with thiobarbituric acid. It is supposed that in these cases the cross-linked protein contains instead of malondialdehyde other reactive aldehydes.

Adolescent↗
PubMedDate not supplied

Cellular immunohistochemical localization of the matricellular protein myocilin in the intervertebral disc.

Myocilin is a 55-57-kDa protein that is a member of the olfactomedin protein family. It is expressed in the cornea, sclera and trabecular network of the eye, myelinated peripheral nerves, heart, skeletal muscle, trachea and other tissues. Myocilin binds to a domain of fibronectin, type IV collagen and laminen in the trabecular meshwork of the eye, and its expression is influenced by transforming growth factor beta. Because these extracellular matrix components also are common in the intervertebral disc, the objective of our study was to determine whether the matricellular protein myocilin could be detected in the human or sand rat intervertebral disc using immunohistochemistry and to assess its localization. We investigated 16 specimens of human disc tissue and discs from six sand rats. Three human disc cell cultures grown in three-dimensional culture also were evaluated. Immunocytochemical annulus analysis showed the presence of myocilin within the disc cell cytoplasm in some, but not all, cells. Extracellular matrix in both the human and sand rat disc was negative for myocilin localization. Myocilin is believed to play a role in cell-cell adhesion and/or signaling. Myocilin may have such functions within the disc cell population in a manner similar to tenascin, SPARC and thrombospondin, which are other matricellular proteins recently shown to be present in the disc.

Adult↗
PubMed2003

Release of active and depot GDF-5 after adenovirus-mediated overexpression stimulates rabbit and human intervertebral disc cells.

To develop new therapeutic options for the treatment of disc degeneration we tested the possibility of overexpression of active growth and differentiation factor (GDF) 5 and of transforming growth factor (TGF) beta(1) by adenoviral gene transfer and characterized its effect on cell proliferation and matrix synthesis of cultured rabbit and human intervertebral disc cells. Recombinant adenovirus encoding for GDF-5 or TGF-beta(1) was developed and transgene expression characterized by RT-PCR, western blot and ELISA. Growth and matrix synthesis of transduced cells was measured by [(3)H]thymidine or [(35)S]sulfate incorporation. Disc cells expressed the receptors BMPR1A, BMPR1B, and BMPR2, which are relevant for GDF-5 action. Adenovirus efficiently transferred the GDF-5 gene or the TGF-beta(1) gene to rabbit and human intervertebral disc cells. About 50 ng GDF-5 protein/10(6 )cells per 24 h or 7 ng TGF-beta(1) protein/10(6 )cells per 24 h was produced. According to western blotting, two GDF-5 forms, with molecular weights consistent with the activated GDF-5 dimer and the proform, were secreted over the 3 weeks following gene transfer. Overexpressed GDF-5 and TGF-beta(1) were bioactive and promoted growth of rabbit disc cells in monolayer culture. Our results suggest that ex vivo gene delivery of GDF-5 and TGF-beta(1) is an attractive approach for the release of mature and pre-GDF-5 in surrounding tissue. This leads us to hope that it will prove possible to improve the treatment of degenerative disc disease by means of ex vivo gene transfer of single or multiple growth factors.

Adenoviridae↗
PubMed1975

An epidemiological study of the relationship between occupations and acute herniated lumbar intervertebral discs.

A case-control study of the epidemiology of acute herniated lumbar intervertebral discs in the New Haven, Connecticut, area indicates that sedentary occupations increase the risk for herniated lumbar discs, particularly among those aged 35 years and older who have had sedentary jobs for several years. People in occupations requiring prolonged driving of motor vehicles, such as truck drivers, appear to be at particularly high risk. The results of this study provide no evidence that people whose jobs involve heavy manual labour are at greater risk for acute herniated lumbar disc than others of their age and sex.

Adult↗
PubMed1991

Morphometric changes in the heights and anteroposterior diameters of the lumbar intervertebral discs with age.

Changes in the heights and anteroposterior diameters of human lumbar intervertebral discs have been studied by means of measurements from radiographs. The results confirm previous reports that there is overall increase in the various dimensions of the disc with age. Growth of the discs apparently does not follow a linear pattern. There are alternating periods of overgrowth and thinning. After the 5th decade of life there is an appreciable decline of disc height. The significance of the findings is discussed.

Adolescent↗
PubMed2006

Calcium phosphate microcrystal deposition in the human intervertebral disc.

A variety of crystals have been identified in both normal and pathological connective tissues. Calcium phosphate 'cuboidal' microcrystal deposition has been found, using transmission electron microscopy (TEM), in femoral articular cartilage, where they are distributed as a band 5-50 microm beneath the articular surface. These cuboid microcrystals have been identified as magnesium whitlockite. Our objective was to investigate their presence in the human intervertebral disc. In this study, two degenerate and 15 scoliotic discs were examined using light microscopy and TEM techniques to determine the presence of calcium phosphate crystals. Calcium pyrophosphate dihydrate (CPPD) deposition was identified in one degenerate disc specimen. Using TEM and electron probe analysis, cuboid microcrystals were identified in the annulus fibrosus and nucleus pulposus of both degenerate specimens, but not in the discs from young scoliotic patients. Cuboid microcrystal deposition was found predominantly around cells, which were mainly necrotic, with some association with extracellular lipidic/membranous debris. This is the first TEM report of whitlockite in the intervertebral disc. In one specimen coexistence of cuboid and CPPD crystal deposition was found.

Adult↗
PubMed2006

Modeling changes in intervertebral disc mechanics with degeneration.

Mechanical response of the spine to various dynamic loading conditions can be analyzed by way of in vitro and in vivo studies. Ethical concerns, interpretation of conclusions reached in animal studies, and lack of detailed stress distributions in the disc components are the major disadvantages of relying solely on in vivo studies. Intraspecimen variability, difficulty in including muscle activity, and inability to mimic fluid exchange into the disc during unloading are some of the disadvantages of in vitro models. The poroelastic finite element models can provide a method of understanding the relationship between biomechanical performance of the disc due to cyclic loading and disc degeneration. A poroelastic finite element model, including regional variation of strain-dependent permeability and osmotic pressure, was used to study the effect of disc degeneration on biomechanical properties as well as propagation of failure in the disc components when cyclic loading was applied to the lumbar disc. The results predicted that healthy discs were much more flexible than degenerated discs, and the disc stiffness decreased with increasing the number of load cycles independent of degenerative condition. Failure was found to progress as the drained elastic properties of the disc components decreased due to the presence of failure. Poroelastic finite element modeling, including strain-dependent permeability and osmotic pressure, is the most advanced analytical tool currently available that can be used to understand how cyclic loading affects the biomechanical characteristics of a degenerated lumbar disc. However, a complete understanding of behavior of the intervertebral disc will ultimately be achieved only with use of a combination of computational models together with in vitro and in vivo experimental methods. Finite element models of discs with varying degrees of disc degeneration will help clinicians understand the initiation and progression of disc failure and degeneration and will assist in the development of approaches to stimulate the regeneration of disc tissues.

Animals↗