Histological Degeneration Score Research Articles

Vertebral Endplate Defects Induced Mechanical Alterations and Disc Calcification.

Cross sectional comparative study. The current study aims to explore the calcification potential (BMP2 expression) of intervertebral discs and its association with the presence of vertebral endplate defects visible on MRI. Forty-seven herniated lumbar disc samples obtained from patients aged 20-76 (31M/16F) undergoing surgery. Five-µm thin sections were stained with H&E in order to assign a histological degeneration score (HDS) from 0-15 on the basis of cell density (0-5), structural alterations (0-4), granular changes (0-3) and mucus degeneration (0-3). Sections were immuno-stained with anti BMP-2 antibodies to observe the calcification potential in these discs. In addition, pre-operativeT2-T1 W MRI images of the lumbar spine were analyzed for the presence and type (typical or atypical) of vertebral endplate defects, grade of disc degeneration (Pfirrmann grade I-V), presence of high intensity zones (HIZ), and Modic changes at the operated level. Vertebral endplate defects, Modic changes & HIZ were observed in 81%, 29% and 21% of patients respectively. Mean HDS & BMP-2 expression was 9 ± 2 and mean 71 ± 36spots/mm2 respectively. Discs with adjacent vertebral endplate defects showed increased cell density (P = .004), mucus degeneration (P = .002), HDS (P = .01) and BMP-2 expression (P = .01). Discs with HIZ also had increased HDS, but significance was seen with increased BMP2 expression (P = .006). HDS showed a positive correlation with BMP 2 expression (r = .30, P = .04). These findings suggest that the altered mechanical environment of discs is strongly associated with BMP-2 expression which is an important marker of intervertebral disc calcification.

Expression of GADD45G and CAPRIN1 in Human Nucleus Pulposus: Implications for Intervertebral Disc Degeneration.

Marked cellular changes occur in human intervertebral disc (IVD) degeneration during disc degeneration with biochemical changes. Genome-wide analysis of the DNA methylation profile has identified 220 differentially methylated loci associated with human IVD degeneration. Among these, two cell-cycle-associated genes, growth arrest and DNA damage 45 gamma (GADD45G) and cytoplasmic activation/proliferation-associated protein-1 (CAPRIN1), were focused on. The expression of GADD45G and CAPRIN1 in human IVDs remains unknown. We aimed to examine the expression of GADD45G and CAPRIN1 in human nucleus pulposus (NP) cells and evaluate those in human NP tissues in the early and advanced stages of degeneration according to Pfirrmann magnetic resonance imaging (MRI) and histological classifications. Human NP cells were cultured as monolayers after isolation from NP tissues by sequential enzyme digestion. Total RNA was isolated, and the mRNA expression of GADD45G and CAPRIN1 was quantified using real-time polymerase chain reaction. To examine the effects of pro-inflammatory cytokines on mRNA expression, human NP cells were cultured in the presence of IL-1β. Protein expression was evaluated using Western blotting and immunohistochemistry. GADD45G and CAPRIN1 expression was identified in human NP cells at both mRNA and protein levels. The percentage of cells immunopositive for GADD45G and CAPRIN1 significantly increased according to the Pfirrmann grade. A significant correlation between the histological degeneration score and the percentage of GADD45G-immunopositive cells was identified, but not with that of CAPRIN1-immunopositive cells. The expression of cell-cycle-associated proteins (GADD45G and CAPRIN1) was enhanced in human NP cells at an advanced stage of degeneration, suggesting that it may be regulated during the progression of IVD degeneration to maintain the integrity of human NP tissues by controlling cell proliferation and apoptosis under epigenetic alteration.

Immuohistochemical score of matrix metalloproteinase-1 may indicate the severity of symptomatic cervical and lumbar disc degeneration

BACKGROUND CONTEXTIntervertebral disc (IVD) degeneration is related to numerous risk factors, including obesity. Leptin, one of the commonly measured adipokines, is proven to play an important role in the pathogenesis of IVD degeneration. In the context of IVD degeneration, matrix metalloproteinase-1 (MMP-1), which is upregulated and activated by leptin, is the most abundant catabolic enzyme. It remains unclear which of the factors mentioned above is most strongly associated with IVD degeneration. PURPOSETo investigate the influence of MMP-1 in IVD degeneration, we determined the strength of different predictors, including age, sex, magnetic resonance imaging (MRI), Modic changes (MCs), body mass index (BMI), leptin, and MMP-1. This was achieved by assessing the correlation among these factors and histologic degeneration score (HDS). STUDY DESIGNThis study included 89 patients undergoing cervical discectomy for disc herniation, 93 who underwent lumbar discectomy, and 90 control subjects. Herniated disc tissue and plasma were used after the study was approved by the Human Ethics Review Committee at the authors’ institution. METHODSHematoxylin and eosin (H&E), Alcian blue–PAS and immunohistochemical (IHC) staining were performed to measure the expression levels of leptin and MMP-1. Circulating plasma levels of leptin and MMP-1 were measured using an enzyme-linked immunosorbent assay. To assess the correlation with HDS, measurements of age, sex, BMI, MRI scale, MCs scale, leptin/MMP-1 plasma concentration, and leptin/MMP-1 IHC expression were analyzed. RESULTSPatients with cervical or lumbar discectomy had significantly higher BMI than controls. Significantly more men than women were involved in the lumbar patients as compared with the cervical patients and the control subjects. After adjustment for age and sex, plasma leptin and leptin IHC score correlated significantly with BMI in patients with cervical or lumbar discectomy. Age, sex, MRI scale, MCs scale, and leptin/MMP-1 plasma concentration were not positively correlated with HDS. HDS was significantly associated with BMI, leptin IHC score, and MMP-1 IHC score. After a stepwise-multiple linear regression analysis to evaluate the strength of the correlations between HDS and various factors, only the MMP-1 IHC score demonstrated an independent association with HDS in patients with degeneration of the cervical or lumbar disc. CONCLUSIONSMMP-1 IHC score is an independent predictor of the severity of cervical or lumbar IVD degeneration. CLINICAL SIGNIFICANCEMMP-1 IHC score may be used as an indicator of IVD degeneration.

Disc cell therapy with bone-marrow-derived autologous mesenchymal stromal cells in a large porcine disc degeneration model.

Disc regeneration through matrix-assisted autologous mesenchymal stromal cell therapy seems promising against disc degeneration with convincing results in small animal models. Whether these positive results can be transferred to larger animal models or humans is unclear. Fibrin matrix-assisted autologous bone-marrow-derived mesenchymal stromal cell therapy was compared to acellular fibrin matrix therapy in a porcine in vivo model. First, disc degeneration was induced by annular puncture and partial nucleotomy with a large 16G-needle, and 12weeks later, disc therapy was performed in a second surgery with a thinner 26G needle. Seventy-two lumbar discs from 12 aged adult pigs were evaluated by histology, micro-CT, and gene expression analysis 13 and 24 weeks after nucleotomy and 1 and 12 weeks after treatment, respectively. Radiologic disc height was not significantly different in both treatment groups. In the semi-quantitative histologic degeneration score, significant disc degeneration was still evident 1week after treatment both in the mesenchymal stromal cell group and in the acellular fibrin matrix group. 12 weeks after treatment, degeneration was, however, not further increased and mesenchymal-stromal-cell-treated discs showed significantly less disc degeneration in the annulus fibrosus (p = 0.02), whereas reduction in the nucleus pulposus did not reach statistical significance. Cell treatment compared to matrix alone found less Col1 gene expression as a marker for fibrosis and more expression of the trophic factor BMP2 in the nucleus pulposus, whereas the inflammation marker IL1ß was reduced in the annulus fibrosus. Disc treatment with fibrin matrix-assisted autologous mesenchymal stromal cells reduced degenerative findings compared to acellular fibrin matrix alone. Regenerative changes, however, were not significant for all parameters showing limitations in a large biomechanically demanding model with aged discs. These slides can be retrieved under Electronic Supplementary Material.

Quantitative MRI in early intervertebral disc degeneration: T1rho correlates better than T2 and ADC with biomechanics, histology and matrix content.

IntroductionLow-back pain (LBP) has been correlated to the presence of intervertebral disc (IVD) degeneration on T2-weighted (T2w) MRI. It remains challenging, however, to accurately stage degenerative disc disease (DDD) based on T2w MRI and measurements of IVD height, particularly for early DDD. Several quantitative MRI techniques have been introduced to detect changes in matrix composition signifying early DDD. In this study, we correlated quantitative T2, T1rho and Apparent Diffusion Coefficient (ADC) values to disc mechanical behavior and gold standard early DDD markers in a graded degenerated lumbar IVD caprine model, to assess their potential for early DDD detection.MethodsLumbar caprine IVDs were injected with either 0.25 U/ml or 0.5 U/ml Chondroïtinase ABC (Cabc) to trigger early DDD-like degeneration. Injection with phosphate-buffered saline (PBS) served as control. IVDs were cultured in a bioreactor for 20 days under axial physiological loading. High-resolution 9.4 T MR images were obtained prior to intervention and after culture. Quantitative MR results were correlated to recovery behavior, histological degeneration grading, and the content of glycosaminoglycans (GAGs) and water.ResultsCabc-injected IVDs showed aberrancies in biomechanics and loss of GAGs without changes in water-content. All MR sequences detected changes in matrix composition, with T1rho showing largest changes pre-to-post in the nucleus, and significantly more than T2 and ADC. Histologically, degeneration due to Cabc injection was mild. T1rho nucleus values correlated strongest with altered biomechanics, histological degeneration score, and loss of GAGs.ConclusionsT2- and T1rho quantitative MR-mapping detected early DDD changes. T1rho nucleus values correlated better than T2 and ADC with biomechanical, histological, and GAG changes. Clinical implementation of quantitative MRI, T1rho particularly, could aid in distinguishing DDD more reliably at an earlier stage in the degenerative process.

Assessment of the correlation between histological degeneration and radiological and clinical parameters in a series of patients who underwent lumbar disc herniation surgery

Background and objectiveThe use of histological degeneration scores in surgically-treated herniated lumbar discs is not common in clinical practice and its use has been primarily restricted to research. The objective of this study is to evaluate if there is an association between a higher grade of histological degeneration when compared with clinical or radiological parameters. Patients and methodRetrospective consecutive analysis of 122 patients who underwent single-segment lumbar disc herniation surgery. Clinical information was available on all patients, while the histological study and preoperative magnetic resonance imaging were also retrieved for 75 patients. Clinical variables included age, duration of symptoms, neurological deficits, or affected deep tendon reflex. The preoperative magnetic resonance imaging was evaluated using Modic and Pfirrmann scores for the affected segment by 2 independent observers. Histological degeneration was evaluated using Weiler's score; the presence of inflammatory infiltrates and neovascularization, not included in the score, were also studied. Correlation and chi-square tests were used to assess the association between histological variables and clinical or radiological variables. Interobserver agreement was also evaluated for the MRI variables using weighted kappa. ResultsNo statistically significant correlation was found between histological variables (histological degeneration score, inflammatory infiltrates or neovascularization) and clinical or radiological variables. Interobserver agreement for radiological scores resulted in a kappa of 0.79 for the Pfirrmann scale and 0.65 for the Modic scale, both statistically significant. ConclusionsIn our series of patients, we could not demonstrate any correlation between the degree of histological degeneration or the presence of inflammatory infiltrates when compared with radiological degeneration scales or clinical variables such as the patient's age or duration of symptoms.

Percutaneous posterolateral approach for the simulation of a far-lateral disc herniation in an ovine model.

This work describes a minimally invasive damage model for ovine lumbar discs via partial nucleotomy using a posterolateral approach. Two cadavers were dissected to analyze the percutaneous corridor. Subsequently, 28 ovine had their annulus fibrosus punctured via awl penetration under fluoroscopic control and nucleus pulposus tissue removed via rongeur. Efficacy was assessed by animal morbidity, ease of access to T12-S1 disc spaces, and production of a mechanical injury as verified by discography, radiography, and histology. T12-S1 were accessible with minimal nerve damage morbidity. Scar tissue sealed the disc puncture site in all animals within 6weeks, withstanding 1 MP of intradiscal pressure. Partial nucleotomy led to a significant reduction in intervertebral disk height and an increased histological degeneration score. Inducing a reproducible injury pattern of disc degeneration required minimal time, effort, and equipment. The posterolateral approach allows operation on several discs within a single surgery and multiple animal surgeries within a single day.

Validation of the intervertebral disc histological degeneration score in cervical intervertebral discs and their end plates

Background ContextVertebral joints consist of intervertebral discs (IVDs) and cartilaginous end plates (EP) that lie superiorly and inferiorly to the IVDs and separate them from the adjacent vertebral bodies. With aging, both IVDs and EPs undergo degeneration. The Histologic Degeneration Score (HDS) is a grading system that microscopically evaluates the degree of degeneration in lumbar discs and predicts it with high accuracy basing on several histological markers of IVD and EP. There is currently a lack of validated histologic grading schemes for cervical spine degeneration. PurposeThe aim of our study was to describe the changes in cervical IVDs and EPs with degeneration and to test the validity of the HDS in the cervical spine. Study DesignA histological study on degenerative changes in cervical IVDs and EPs was conducted. MethodsThirty human cadavers were dissected to obtain 60 cervical IVDs from the lower half of C4 to the level of the upper half of C6. The IVDs were carefully excised along with EPs and then sectioned to obtain midsagittal samples for macroscopic examination according to a five-grade classification system. The samples were further dissected, fixed, and stained for histological examination according to HDS. ResultsThirty C4–C5 IVDs and thirty C5–C6 IVDs were macroscopically examined for degeneration. The averaged Thompson's grade was found to be 2.9±1.3. The mean HDS for IVDs was 13.1±5.8 and for EP was 10.2±5.2. The interrater reliability estimates indicated excellent reliability (κ values>0.81, percentage agreement 86.1%-96.1%). Spearman's rank correlation coefficients for IVD and EP scores showed good consistency in predicting macroscopic degeneration. No significant differences were found between the values for cervical IVDs and EPs in the present study and those for lumbar discs derived in previous studies. ConclusionsThe HDS was confirmed to be as accurate in predicting the degree of degeneration in the cervical spine as in the lumbar region. To our best knowledge, this is the first reported and validated histological classification system intended for assessing histological degeneration in the cervical spine. Therefore, HDS can be recommended for academic and pathologic purposes in cervical disc degeneration.

P53 and VEGF expression in human temporomandibular joint discs with internal derangement correlate with degeneration

Aim: Temporomandibular joint (TMJ) disorders are one of the most relevant causes of chronic facial pain and disability. During histopathological conditions biomolecular mechanisms occur inducing histologic changes of the tissue itself. Human Tumor Protein p53 and Vascular Endothelial Growth Factor are related with cell-cycle control, angiogenesis and both play a central role during inflammation. The purpose of the present research was to investigate the immunoexpression and immunolocalization of Human Tumor Protein p53 and Vascular Endothelial Growth Factor in temporomandibular joint discs of individuals with internal derangement with anterior disc displacement in order to gain insights into the apoptotic and angiogenetic processes in the three bands of articular discs with or without reduction and compare them to the histological degeneration score. Methods: Paraffin samples of eighteen displaced temporomandibular joint and four control discs were analyzed by immunohistochemistry for the above evaluations. Results: Data showed a strong Human Tumor Protein p53 and Vascular Endothelial Growth Factor immunoexpression in the anterior and intermediate disc areas and a weak immunoexpression in posterior area of anterior disc displacement with reduction patients while anterior disc displacement without reduction patients demonstrated a weak Human Tumor Protein p53 and Vascular Endothelial Growth Factor immunolabelling in the anterior and intermediate areas and a strong immunoexpression in posterior band. These immunoexpressions correlated with histological degeneration score. Conclusions: According to our results it can be assumed in that when the more histopathological changes in the disc are releaved, major levels of p53 and VEGF are produced.

Mechanism of alpha-lipoic acid in treating TNBS-induced colitis in mice

Objective: To investigate whether α-lipoic acid (ALA) regulates autophagy in the pathogenesis of colitis through the mammalian target of rapamycin (mTOR) signaling pathway. Methods: Balb/c mouse colitis model was induced with 2, 4, 6-trinitrobenzenesulfonic acid (TNBS). Male Balb/c mice (22-25 g) were divided into four groups: control group, ALA group, colitis group, and ALA treatment group, with 10 mice in each group. ALA was administered at a dose of 80 mg/kg once a day for 7 days. The colon weight index, the disease activity index (DAI) and the histologic degeneration score (HDS) of colon tissue in each group were calculated. The autophagy gene Beclin-1 mRNA level was detected by RT-PCR. The levels of mTOR, phosphorylated mTOR (p-mTOR), and Beclin-1 proteins were detected by Western blot. Results: Compared with the control group, there was no statistically significant difference in colon weight index in the ALA group[(9.21±0.57)vs(8.91±0.91)g/kg, P>0.05], but increased in the colitis group [(12.65±1.33)g/kg, P<0.05] and decreased in the ALA treatment group [(10.04±1.02)g/kg, P<0.05]; there were no significant differences in DAI or HDS in the ALA group, but significantly increased in the colitis group, and decreased in the ALA treatment group (all P<0.05). The Beclin-1 mRNA and protein levels showed no significant differences between the control and the ALA groups (1.00±0.12 vs 1.05±0.05, 1.00±0.11 vs 1.00±0.06). However, the expression of Beclin-1 was significantly decreased in the colitis group compared to the control group (0.51±0.07 vs 1.00±0.12, 0.52±0.07 vs 1.00±0.11, both P<0.05), but significantly increased in the ALA treatment group compared to the colitis group (1.75±0.09 vs 0.51±0.07, 1.82±0.14 vs 0.52±0.07, both P<0.05). The mTOR total protein levels were not significantly different among the four groups, but the p-mTOR level was significantly higher in the colitis group than in the control group (3.07±0.20 vs 1.00±0.07), and reduced in the ALA treatment group than in the colitis group (1.49±0.11 vs 3.07±0.20) (all P<0.05). Conclusion: ALA may improve the TNBS-induced colitis in mice by inhibiting the phosphorylation of mTOR to promote autophagy.

Lumbar disc herniation: Is there an association between histological and magnetic resonance imaging findings?

Background:Although validated radiological scoring systems and histological scoring system of surgically removed degenerated disc are used in assessment of progression of intervertebral disc degeneration, there have not been many studies that integrate these two aspects of assessments. The data available in this respect are very limited. This clinical study was designed to find the correlation between quantitative radiological score (Pfirmann grading system and Modic changes [MC]) and quantitative histological degeneration score (HDS).Materials and Methods:A cohort of 77 patients (45 males, 32 females; mean age of 38 years [range 18–58 years]) who presented with complaints of discogenic pain or radiculopathy at single level were assessed radiologically. They were graded according to the radiological pattern. The surgically excised disc specimen was graded according to HDS. The degree of radiological changes were correlated with the degree of histological changes.Results:Though the overall HDS (0–15) did not show statistically significant correlation with Pfirmann grading system, there were positive association found between mucoid degeneration, chondrocyte proliferation with the Pfirmann grading and mucoid degeneration, which were statistically significant. Female sex also had a higher association with instability pattern.Conclusion:The study shows that the Pfirmann grading system, MCs and HDS can reliably be used as scoring systems for assessing lumbar disc degeneration. The radiological assessment can be used as a noninvasive tool to assess the probable change in content rather than the microstructure of a disc undergoing degeneration.

Histological Analysis of Degenerate Discs (Disc Study)—is there Support for Infection as a Possible Etiology for Disc Degeneration?

Introduction A controversial study implicated bacterial factors in chronic back pain and reported a potential treatment option with long-term antibiotics. Currently, a multicentric case–control study is being conducted looking at bacterial in surgical disc specimens: Is growth a true infection or a contaminant? A histopathological arm has been added to aid in this differentiation. The aim of this study was to look for histopathological evidence of degeneration and inflammation and to identify histological differences in surgically excised disc samples of patients who grew bacteria on disc cultures compared with those that did not. Material and Methods A subset of patients as a part of a DISC study operated at Prince of Wales Public and Private Hospitals, Sydney were included in the study. The study was approved by HREC 13/218 started in 2013 and is ongoing. Cervical and lumbar disc samples were sent for both bacterial culture and histopathology. Histopathology was graded by two independent pathologists (blinded to culture results) using the previously evidenced histologic degeneration score (HDS) and a newly devised disc inflammatory score (DIS). Demographic factors, surgical factors and MODIC changes on MRI were correlated with histopathology data. Results There were 125 samples from 104 patients. Of the patients, there was a 54:50, male to female ratio. Discs levels from the cervical and lumbar regions were sampled (45:80, respectively). Of the total number of samples 33/125 (26.4%) grew bacteria, and 57.6% (19/33) of these grew Propionibacterium acnes. Using the HIS, only disc degeneration was found, with no significant evidence of inflammation in disc specimens. Conclusion In our histopathological study, there was no evidence of inflammation in degenerate discs and no differences in histopathology between positive and negative disc cultures. This raises a strong possibility of contamination in positive cultures of disc samples. In addition to this, there is further validation required of the new DIS score.

Influence of lumbar intervertebral disc degeneration on the outcome of total lumbar disc replacement: a prospective clinical, histological, X-ray and MRI investigation

The role of fusion of lumbar motion segments for the treatment of axial low back pain (LBP) from lumbar degenerative disc disease (DDD) without any true deformities or instabilities remains controversially debated. In an attempt to avoid previously published and fusion-related negative side effects, motion preserving technologies such as total lumbar disc replacement (TDR) have been introduced. The adequate extent of preoperative DDD for TDR remains unknown, the number of previously published studies is scarce and the limited data available reveal contradictory results. The goal of this current analysis was to perform a prospective histological, X-ray and MRI investigation of the index-segment's degree of DDD and to correlate these data with each patient's pre- and postoperative clinical outcome parameters from an ongoing prospective clinical trial with ProDisc II (Synthes, Paoli, U.S.A.). Nucleus pulposus (NP) and annulus fibrosus (AF) changes were evaluated according to a previously validated quantitative histological degeneration score (HDS). X-ray evaluation included assessment of the mean, anterior and posterior disc space height (DSH). MRI investigation of DDD was performed on a 5-scale grading system. The prospective clinical outcome assessment included visual analogue scale (VAS), Oswestry Disability Index (ODI) scores as well as the patient's subjective satisfaction rates. Data from 51 patients with an average follow-up of 50.5 months (range 6.1-91.9 months) were included in the study. Postoperative VAS and ODI scores improved significantly in comparison to preoperative levels (p < 0.002). A significant correlation and interdependence was established between various parameters of DDD preoperatively (p < 0.05). Degenerative changes of NP tissue samples were significantly more pronounced in comparison to those of AF material (p < 0.001) with no significant correlation between each other (p > 0.05). Preoperatively, the extent of DDD was not significantly correlated with the patient's symptomatology (p > 0.05). No negative influence was associated with increasing stages of DDD on the postoperative clinical outcome parameters following TDR (p > 0.05). Increasing stages of DDD in terms of lower DSH scores were not associated with inferior clinical results as outlined by postoperative VAS or ODI scores or the patient's subjective outcome evaluation at the last FU examination (p > 0.05). Conversely, some potential positive effects on the postoperative outcome were observed in patients with advanced stages of preoperative DDD. Patients with more severe preoperative HDS scores of NP samples demonstrated significantly lower VAS scores during the early postoperative course (p = 0.02). Increasing stages of DDD did not negatively impact on the outcome following TDR in a highly selected patient population. In particular, no preoperative DDD threshold value was identified from which an inferior postoperative outcome could have been deduced. Conversely, some positive effects on the postoperative outcome were detected in patients with advanced stages of DDD. Combined advantageous effects of progressive morphological structural rigidity of the index segment and restabilizing effects from larger distraction in degenerated segments may compensate for increasing axial rotational instability, one of TDR's perceived disadvantages. Our data reveal a "therapeutic window" for TDR in a cohort of patients with various stages of DDD as long as preoperative facet joint complaints or degenerative facet arthropathies can be excluded and stringent preoperative decision making criteria are adhered to. Previously published absolute DSH values as contraindication against TDR should be reconsidered.

Histological analysis of surgical lumbar intervertebral disc tissue provides evidence for an association between disc degeneration and increased body mass index

BackgroundAlthough histopathological grading systems for disc degeneration are frequently used in research, they are not yet integrated into daily care routine pathology of surgical samples. Therefore, data on histopathological changes in surgically excised disc material and their correlation to clinical parameters such as age, gender or body mass index (BMI) is limited to date. The current study was designed to correlate major physico-clinical parameters from a population of orthopaedic spine center patients (gender, age and BMI) with a quantitative histologic degeneration score (HDS).MethodsExcised lumbar disc material from 854 patients (529 men/325 women/mean age 56 (15-96) yrs.) was graded based on a previously validated histologic degeneration score (HDS) in a cohort of surgical disc samples that had been obtained for the treatment of either disc herniation or discogenic back pain. Cases with obvious inflammation, tumor formation or congenital disc pathology were excluded. The degree of histological changes was correlated with sex, age and BMI.ResultsThe HDS (0-15 points) showed significantly higher values in the nucleus pulposus (NP) than in the annulus fibrosus (AF) (Mean: NP 11.45/AF 7.87), with a significantly higher frequency of histomorphological alterations in men in comparison to women. Furthermore, the HDS revealed a positive significant correlation between the BMI and the extent of histological changes. No statistical age relation of the degenerative lesions was seen.ConclusionsThis study demonstrated that histological disc alterations in surgical specimens can be graded in a reliable manner based on a quantitative histologic degeneration score (HDS). Increased BMI was identified as a positive risk factor for the development of symptomatic, clinically significant disc degeneration.

The role of matrix metalloproteinase 9 in intervertebral disc degeneration

The present study investigates the histological alterations and expression of matrix metalloproteinase 9 (MMP-9) in disc specimens of 43 patients who underwent surgery for lumbar disc herniation. The immunostaining for MMP-9 was evaluated semi-quantitatively. Histologic degeneration was scored between 0 and 12 depending on the degree of chondrocyte proliferation and presence of tears and clefts, granular changes and mucous degeneration. Herniation was graded as grade 1 (protrusion), grade 2 (extrusion) or grade 3 (sequestration) on MRI. Although there was no significant statistical difference between the histologic degeneration score and age, degenerative changes were more pronounced in higher grade of herniation ( p < 0.0001). MMP-9 expression was related to histologic degenerative score in all age groups ( p = 0.0065). MMP-9 was also related to herniation grade in patients younger than 30 years of age ( p = 0.0037). No significant association was found between MMP-9 expression and herniation grade in patients who were 30–60 years or over 60 years of age.

Age-Related Variation in Cell Density of Human Lumbar Intervertebral Disc

changes in cell density of endplate (EP), nucleus pulposus (NP), and anulus fibrosus (AF) during ageing were systematically investigated in defined regions of interest in complete human motion segments. to elucidate cell density and total cell number in distinct anatomic regions of the intervertebral disc; to test effects of gender, level and age on cell density; and to correlate changes in cell density with histologic signs of disc degeneration. the available information on the cell density within intervertebral discs and its age-related changes is sparse. This knowledge, however, is a crucial prerequisite for cell-based tissue engineering approaches of the intervertebral disc. in 49 complete cross-sections from lumbar motion segments (newborn to 86 years) from 22 specimens, cell density was determined by the Abercrombie method in EP, NP, and AF, and total cell number was counted per region of interest. cell density in EP, NP, and AF decreased significantly from 0 to 16 years with the main changes occuring from 0 to 3 years for NP and AF. No significant variations were observed thereafter. We found a significant correlation of cell density and histologic degeneration score between 0 and 1, but not for scores >1. Gender and disc level did not influence cell density. This study provides data concerning the total number of cells in the various regions of the intervertebral disc for different age groups. This knowledge will be beneficial for cell-based treatment approaches, which may evolve in the future.

Surface topography of viable articular cartilage measured with scanning white light interferometry

By means of scanning white light interferometry, develop a noncontact, nondestructive technique capable of measuring surface topography of viable cartilage. Using full thickness cylindrical cartilage explants obtained from bovine calf knees, experiments were performed to produce a surface preparation protocol that yields highly repeatable topographical measurements while maintaining cartilage viability. To further validate the technique, a series of human talar cartilage samples, displaying varying degrees of cartilage degeneration, was then subjected to interferometric measurements and compared to their histology. A key aspect of the technique of surface topographic measurement by interferometry was the development of an optimal surface preparation process. The technique was successfully validated against standard 2-D profilometry. The intrinsic variability of the technique is less than 2%, which is much less than the average point-to-point variability of 17% observed across a cartilage specimen. The technique was hence sufficiently sensitive to readily detect differences in roughness between surfaces of healthy cartilage in different locations on the bovine knee. Thus, the average roughness of the medial explants exceeded that of the lateral explants by 0.35 microm Ra (P=0.003) and the roughness of the trochlear explants exceeded that of the condylar explants by 0.55 microm Ra (P<0.0001). Also, applying this technique to diseased human talar cartilage samples, a statistically significant increase in the average surface roughness value per unit increase in histological degeneration score was observed (> or =0.2 microm Ra, P< or =0.041), making surface roughness obtained via interferometry a useful parameter for evaluating cartilage health nondestructively. The aim of developing a protocol based on white light interferometry to measure the surface topography of viable articular cartilage was achieved. This interferometric technique opens the door to monitoring the surface topography of live cartilage, as is desirable for ex vivo tests on cartilage explants.

Type II collagen synthesis in the articular cartilage of a rabbit model of osteoarthritis: expression of type II collagen C-propeptide and mRNA especially during early-stage osteoarthritis

BackgroundThe aim of this study was to observe time course changes in type II collagen synthesis in various regions of articular cartilage affected with osteoarthritis (OA) by examining the expression of type II collagen C-propeptide (pCOL II-C) and mRNA in a rabbit OA model. MethodsOsteoarthritis was experimentally induced by partial lateral meniscectomy in the knees of Japanese white rabbits. The cartilage of the animals was then examined histologically over time. The degenerative area of articular cartilage was divided into three areas, according to the degree of degeneration. The ability to synthesize type II collagen was estimated by the immunohistological staining of pCOL II-C and the in situ hybridization of mRNA in type II collagen. ResultsThe positive rate of pCOL II-C immunostaining in chondrocytes was highest in the central-degenerative region 1week after surgery, and the highest rate in the para-degenerative region was observed 2 and 4weeks after surgery. The percentage of pCOL II-C positive cells increased as the histological degeneration score increased to moderate degeneration and then decreased with further progression of the severity of cartilage degeneration. Examination by in situ hybridization revealed that the regions marked by strong pCOL II-C mRNA expression were similar to those indicated by the immunohistology results. ConclusionsThese results suggest that the type II collagen-synthesizing potential of chondrocytes is highest in moderately degenerated areas of OA articular cartilage. Cartilage repair continues to be seen even as OA advances, although the reaction varies depending on the stage of OA.

Expression and Distribution of Tumor Necrosis Factor Alpha in Human Lumbar Intervertebral Discs: A Study in Surgical Specimen and Autopsy Controls

Immunohistochemical study of tumor necrosis factor alpha expression in autopsy and surgical specimens of human lumbar intervertebral discs. To investigate the occurrence and localization of tumor necrosis factor alpha in intervertebral disc tissue and to correlate its expression with age and the degree of disc degeneration. The source and origin of discogenic pain are as yet unknown. Recently identified changes of the cellular phenotype during senescence and disc pathology with partly phagocytic properties suggest an 'inflammatory' phenotype. Tumor necrosis factor alpha is one of the most potent proinflammatory cytokines possibly modulating cellular phenotypes. It may also promote pain induction. Very little is known about the occurrence and localization of tumor necrosis factor alpha in intervertebral disc tissue of defined age and degree of histologic tissue degeneration. The study population comprised 20 cross-sections of the complete motion segment of human lumbar vertebrae (age range 0-86 years) obtained at autopsy and 28 surgical disc specimens of individuals undergoing lumbar surgical interventions for various reasons. The temporospatial distribution of tumor necrosis factor alpha-positive cells using a polyclonal antibody was correlated with a histologic degeneration score. Tumor necrosis factor alpha is expressed substantially in (nonsymptomatic) autopsy material in fetal/infantile and older adult nucleus pulposus, whereas it is sparsely expressed in adolescent and young adult nucleus pulposus. In the anulus fibrosus, tumor necrosis factor alpha is not found in young adults (<25 years), but then significantly increases in extent. In contrast, symptomatic nucleus pulposus and anulus fibrosus (surgical material) contain substantially more tumor necrosis factor alpha-positive cells. A significant positive correlation of tumor necrosis factor alpha expression and disc degeneration (histologic degeneration score) was found for the anulus fibrosus in both sample groups. In the surgical material, an additional significant positive correlation was identified for nuclear tumor necrosis factor alpha, disc degeneration, and age. Tumor necrosis factor alpha is substantially expressed in disc material of symptomatic patients (surgical specimens) in comparison to samples taken at autopsy. The expression of tumor necrosis factor alpha in early fetal/infantile nucleus pulposus may indicate 'physiologic' tissue disarrangement with closure of the blood vessel canals. The expression of tumor necrosis factor alpha in adult discs, in contrast, is statistically associated with disc degeneration. Its occurrence in adults of more advanced age suggests that tumor necrosis factor alpha is not involved in the initiation of disc degeneration, but may be associated with further promotion of degenerative disarrangement and pain induction.