Intervertebral disk degeneration related to reduced vertebral marrow perfusion at dynamic contrast-enhanced MRI

Does vertebral osteoporosis delay or accelerate lumbar disc degeneration? A systematic review

The effect of vertebral osteoporosis on disc degeneration is still debated. The purpose of this study was to provide a systematic review of studies in this area to further reveal the relationship between the two. Relevant studies were searched in electronic databases, and studies were screened according to inclusion and exclusion criteria, and finally, basic information of the included studies was extracted and summarized. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A total of 34 publications spanning 24 years were included in our study. There were 19 clinical studies, including 12 prospective studies and 7 retrospective studies. Of these, 7 considered vertebral osteoporosis to be positively correlated with disc degeneration, 8 considered them to be negatively correlated, and 4 considered them to be uncorrelated. Two cadaveric studies were included, one considered the two to be negatively correlated and one considered them not to be correlated. Seven animal studies were included, of which five considered a positive correlation between vertebral osteoporosis and disc degeneration and two considered a negative correlation between the two. There were also 6 studies that used anti-osteoporosis drugs for intervention, all of them were animal studies. Five of them concluded that vertebral osteoporosis was positively associated with disc degeneration, and the remaining one concluded that there was no correlation between the two. Our systematic review shows that the majority of studies currently consider an association between vertebral osteoporosis and disc degeneration, but there is still a huge disagreement whether this association is positive or negative. Differences in observation time and follow-up time may be one of the reasons for the disagreement. A large number of clinical and basic studies are still needed in the future to further explore the relationship between the two.

Two dimensional automatic active shape model of degenerative disc repaired by low-intensity laser

OBJECTIVE

Intervertebral disc degeneration is the main factor causing low back pain, and the related long-term treatment can improve the situation of degeneration. This study aimed to investigate the effect of low-intensity laser irradiation on the repair of degenerative intervertebral disc by two dimensional automatic active shape model (2D-AASM).

METHODS

Nine Bama miniature pigs were randomly divided into three groups: control group (Con), model group (Mod) and laser treatment group (Las). After one month, the discs were treated with low-energy laser for another month. MRI was performed for one month, and the statistical shape model and 2D-AASM of intervertebral disc were established based on the minimum description length method.

RESULTS

The model established by the proposed method is more accurate and the segmentation result is more accurate. From the segmented T2-weighted image, the signal intensity of the Mod group decreased significantly, and the signal intensity in the Las group was moderate and high compared with the Mod group. The HE staining display the structure of Con group was damaged, and the construction of Las group was restored compared with Mod group.

CONCLUSIONS

The 2D-AASM method effectively improves the accuracy of intervertebral disc segmentation. The low-intensity laser has a protective effect on the repair of the degenerative intervertebral disc.

Quantifying lumbar vertebral perfusion by a Tofts model on DCE-MRI using segmental versus aortic arterial input function

The purpose of this study was to investigate the influence of arterial input function (AIF) selection on the quantification of vertebral perfusion using axial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). In this study, axial DCE-MRI was performed on 2 vertebrae in each of eight healthy volunteers (mean age, 36.9 years; 5 men) using a 1.5-T scanner. The pharmacokinetic parameters K^trans, v_e, and v_p, derived using a Tofts model on axial DCE-MRI of the lumbar vertebrae, were evaluated using various AIFs: the population-based aortic AIF (AIF_PA), a patient-specific aortic AIF (AIF_A) and a patient-specific segmental arterial AIF (AIF_SA). Additionally, peaks and delay times were changed to simulate the effects of various AIFs on the calculation of perfusion parameters. Nonparametric analyses including the Wilcoxon signed rank test and the Kruskal–Wallis test with a Dunn–Bonferroni post hoc analysis were performed. In simulation, K^trans and v_e increased as the peak in the AIF decreased, but v_p increased when delay time in the AIF increased. In humans, the estimated K^trans and v_e were significantly smaller using AIF_A compared to AIF_SA no matter the computation style (pixel-wise or region-of-interest based). Both these perfusion parameters were significantly greater using AIF_SA compared to AIF_A.

Association between parity and lumbar spine degenerative disorders in young women

Introduction: Estrogen helps to maintain the health of collagen-containing tissues including the intervertebral disc. Estrogen deficiency after menopause negatively affects the quality of vertebral end plates and induces development of degenerative disc disease (DDD). However, there is no study examining the relationship between parity and spinal degeneration in young women. The aim of this study was to define the relationship between parity and development of vertebral endplate signal changes and DDD in young premenopausal women.Materials and methods: This case-control case study included 224 patients aged 20-40 years with a history of low back pain for at least 3 months. Pfirrmann's grade, Modic changes (MCs), and Schmorl's nodes (SNs) were graded based on magnetic resonance images. Patients' parity, demographics, body mass index, physical activity level, and disability scores were assessed using a questionnaire.Results: The prevalence of abnormal total Pfirrmann's score (>10) and MCs was higher in primiparous patients than multiparous and grand-multiparous; however, it was not statistically significant. The presence of SN was statistically significantly associated with low parity. According to multivariate logistic regression analysis, it was found that the number of births increases by 1 unit, the abnormality in Pfirrmann's score decreases by 1.36 times.Conclusions: This cross-sectional study shows that parity is associated with DDD and vertebral end plate changes. SNs were significantly associated with parity. Modic changes and DDD were less common in grand multipara and multipara young women than in primipara women. These results indicate that low parity may possibly be associated with the development of spinal degeneration.

A retrospective study: Does cigarette smoking induce cervical disc degeneration?

OBJECTIVE

To investigate cigarette smoking's relevance with cervical disc degeneration.

METHODS

We randomly selected 320 patients who came to our spine disease department outpatient clinic with chief complaint of neck-shoulder pain during June 2014-June 2016. According to the detailed smoking history, these patients were divided into 3 different groups, which were active smoker group (AS), passive smoking group (PS) and never-smoker group (NS). Each patient's Miyazaki's magnetic resonance imaging (MRI) classification of cervical disc degeneration was analyzed based on their cervical MRI films. In addition, VAS scores were applied to evaluate the degree of patients' neck-shoulder pain. With the help of statistical techniques, relevance between cigarette smoking, cervical disc degeneration and neck-shoulder pain were analyzed.

RESULTS

In the NS group, the overall Miyazaki score, especially for C2/3, C3/4, C5,6 segments, are superior to those in the PS group, in addition, the Miyazaki scores for C1/2 - C6/7 segments in NS group beat the same segments in AS group with statistical significance (P < 0.05). In the AS and PS group, discs from C4/5 to C5/6 segments which score IV and V on Miyazaki classification account for a larger proportion than those discs from C1/2 to C3/4 segments with statistical significance (P < 0.05). In the AS group, male cases have larger proportion of Miyazaki level IV and V discs than female with statistical significance (P < 0.05). While in the AS and PS group, Miyazaki scores of patients whose smoking history ranges from 5 to 10 years are superior to those with smoking history longer than 10 years, with statistical significance (P < 0.05). In addition, VAS scores also vary among the three groups, in which, VAS scores in AS group are higher than those in the NS group.

CONCLUSION

Smoking could accelerate the process of cervical disc degeneration, presenting with more severe neck-shoulder pain on the patients. In addition, the impact of smoking on the lower cervical discs is greater than the upper cervical discs.

The Clinical Correlations between Diabetes, Cigarette Smoking and Obesity on Intervertebral Degenerative Disc Disease of the Lumbar Spine

Study Design

Retrospective analysis of a nationwide private insurance database. Chi-square analysis and linear regression models were utilized for outcome measures.

Purpose

The purpose of this study was to investigate any relationship between lumbar degenerative disc disease, diabetes, obesity and smoking tobacco.

Overview of Literature

Diabetes, obesity, and smoking tobacco are comorbid conditions known to individually have effect on degenerative disc disease. Most studies have only been on a small populous scale. No study has yet to investigate the combination of these conditions within a large patient cohort nor have they reviewed the combination of these conditions on degenerative disc disease.

Methods

A retrospective analysis of insurance billing codes within the nationwide Humana insurance database was performed, using PearlDiver software (PearlDiver, Inc., Fort Wayne, IN, USA), to identify trends among patients diagnosed with lumbar disc degenerative disease with and without the associated comorbidities of obesity, diabetes, and/or smoking tobacco. Patients billed for a comorbidity diagnosis on the same patient record as the lumbar disc degenerative disease diagnosis were compared over time to patients billed for lumbar disc degenerative disease without a comorbidity. There were no sources of funding for this manuscript and no conflicts of interest.

Results

The total number and prevalence of patients (per 10,000) within the database diagnosed with lumbar disc degenerative disease increased by 241.4% and 130.3%, respectively. The subsets of patients within this population who were concurrently diagnosed with either obesity, diabetes, tobacco use, or a combination thereof, was significantly higher than patients diagnosed with lumbar disc degenerative disease alone (p <0.05 for all). The number of patients diagnosed with lumbar disc degenerative disease and smoking rose significantly more than patients diagnosed with lumbar disc degenerative disease and either diabetes or obesity (p <0.05). The number of patients diagnosed with lumbar disc degenerative disease, smoking and obesity rose significantly more than the number of patients diagnosed with lumbar disc degenerative disease and any other comorbidity alone or combination of comorbidities (p <0.05).

Conclusions

Diabetes, obesity and cigarette smoking each are significantly associated with an increased diagnosis of lumbar degenerative disc disease. The combination of smoking and obesity had a synergistic effect on increased rates of lumbar degenerative disc disease. Patient education and preventative care is a vital goal in prevention of degenerative disc disease within the general population.

Vitamin D improves the content of TGF-β and IGF-1 in intervertebral disc of diabetic rats

OBJECTIVE

The contents of transforming growth factor-β and insulin-like growth factor-1 in disc of diabetic rats were measured at three different periods after injected with 1,25-Dihydroxyvitamin D3, and compared with that in normal rats. The significance of content changes was also discussed.

METHODS

Fourty-five Sprague-Dawley (SD) rats were divided into three groups, namely the experimental group (STZ+calcitriol), control group (STZ+citrate buffer), and normal group (citrate buffer). Complete lumbar discs in these groups were obtained at the second, fourth, sixth week, respectively. After paraffin-embedded sections and HE staining, the structure and morphology changes of disc were observed. The content of transforming growth factor-β and insulin-like growth factor-1 was measured by immunohistochemical method, and the expression of transforming growth factor-β and insulin-like growth factor-1 was detected by Western Blot.

RESULTS

In hematoxylin-eosin staining, degenerative changes were observed in disc of experimental and control group at three different periods, and there were no changes in disc in normal group. Immunohistochemical method indicated the content of transforming growth factor-β and insulin-like growth factor-1 in experimental and control group was significantly lower than normal group at three different periods ( P < 0.05). And there were significant differences between experimental and control group at three different periods ( P < 0.05).

CONCLUSION

Vitamin D can protect the degeneration of intervertebral disc and improve the content of transforming growth factor-β and insulin-like growth factor-1 in the intervertebral disc, which provides a new idea for the prevention and treatment of degenerative changes of the intervertebral disc in diabetic patients. Impact statement No researchers reported Vitamin D could protect degeneration of intervertebral disc. That is to say, we found a new method to prevent and treat degenerative changes of the intervertebral disc in diabetic patients. And Vitamin D prevented the discs by improving the content of TGF-β and IGF-1.

Decrease with aging of the microcirculatory function of the lumbar vertebral marrow preceding the loss of bone material density and the onset of intervertebral discal degeneration: A study about the potential cause

Objective

Using a dynamic computed tomographic perfusion (CTP) imaging method to explore the age-related distribution of the microcirculation perfusion function in the vertebral marrow, the bone material density (BMD), and the intervertebral discal degeneration (IDD). Further, to discuss a possible causation relationship between them.

Methods

One hundred and eighty-six people were randomly enrolled by stratified sampling and grouped by age: ≤15, 16–25, 26–35, 36–45, 46–55, 56–65, 66–75, and ≥76 years old. The average CTP and BMD of the third and fourth lumbar vertebrae marrow were measured and the IDD incidence of the third-fourth vertebrae was assessed. The temporal–spatial distribution patterns of the age-related changes of the CTP, BMD, and IDD were described, and the correlations between them were calculated.

Results

The microcirculatory perfusion function of the vertebral marrow develops to maturity by 25 years and is maintained until age 35, then declines with aging. The BMD grew to a peak from 26 to 45 years old, then decreased yearly. The IDD showed a sudden increase after 45 years of age. The CTP [BF (r = 0.806, P = 0.000), BV (r = 0.685, P = 0.005) and PMB (r = 0.619, P = 0.001)] showed strong positive correlations and CTP [TTP (r = −0.211, P = 0.322) and MTT (r = −0.598, P = 0.002)] showed negative correlations with BMD. The CTP [BF (r = −0.815, P = 0.000), BV (r = −0.753, P = 0.000) and PMB (r = −0.690, P = 0.000)] had strong negative correlations, and CTP [TTP (r = 0.323, P = 0.126) and MTT (r = 0.628, P = 0.001)] had positive correlations with the incidence of IDD.

Conclusion

The decrease with aging of the microcirculatory perfusion in the lumbar vertebral marrow preceded, and is a potential causative factor for the loss of BMD and the onset of IDD.

Dysfunctional microcirculation of the lumbar vertebral marrow prior to the bone loss and intervertebral discal degeneration

STUDY DESIGN

Descriptive study, stratified sampling.

OBJECTIVE

Using dynamic computed tomographic perfusion (CTP) to explore the age-related distribution patterns of the microcirculation perfusion in the vertebral marrow, the vertebral bone mineral density (BMD), and the intervertebral discal degeneration (IDD) further to discuss the possible causation between them.

SUMMARY OF BACKGROUND DATA

A latest viewpoint deemed that reduced blood supply of the vertebral marrow was correlated with an increased incidence of IDD and loss of BMD. However, the causative relationship between them needs more investigation.

METHODS

One hundred eighty-six general people were randomly enrolled by stratified sampling and grouped by age: 15 years or less, 16 to 25 years, 26 to 35 years, 36 to 45 years, 46 to 55 years, 56 to 65 years, 66 to 75 years, and 76 years or more. Both CTP and BMD of the third and fourth lumbar vertebral marrow were measured, and the IDD incidence of the third-fourth vertebrae was assessed. The temporal-spatial distribution patterns of the age-related changes of CTP, BMD, and IDD were described, and the correlations between them were calculated.

RESULTS

Microcirculatory perfusion of the vertebral marrow developed to maturate by 25 years, maintained stable at 35 years, and then declined by age after 35 years. BMD grew to a peak phase in 26 to 45 years and then dropped by years. However, IDD presented a sudden increase after 45 years of age. CTP (blood flow [r=0.806], blood volume [r=0.685], and permeability [r=0.619]) showed strong positive correlations and CTP (time to peak [r=-0.211], mean transit time [r=-0.598]) showed negative correlations with BMD. Meanwhile, CTP (blood flow [r=-0.815], blood volume [r=-0.753], and permeability [r=-0.690]) had strong negative correlations and CTP (time to peak [r=0.323] and mean transit time [r=0.628]) had positive correlations with the incidence of IDD.

CONCLUSION

Aging-related decrease of the microcirculatory perfusion of the lumbar vertebral marrow preceded the loss of BMD and the onset of IDD, indicating their possible causal relationship.

LEVEL OF EVIDENCE

3.

Interference in the endplate nutritional pathway causes intervertebral disc degeneration in an immature porcine model

PURPOSE

Previous studies have shown that blocking the endplate nutritional pathway with bone cement did not result in obvious intervertebral disc degeneration (IDD) in mature animal models. However, there are very few comparable studies in immature animal models. As vertebroplasty currently is beginning to be applied in young, even biologically immature patients, it is important to investigate the effect of cement blocking at the endplate in an immature animal model.

METHODS

Two lumbar intervertebral discs in eight immature pigs were either blocked by cement in both endplate pathways or stabbed with a scalpel in the annulus fibrosus (AF) as a positive control, and with a third disc remaining intact as a normal control. Magnetic resonance imaging (MRI) and histology study were performed.

RESULTS

After three months, the cement-blocked discs exhibited severe IDD, with the percentage of disc-height index (DHI), nucleus pulposus (NP) area, and NP T2 value significantly lower than the normal control. These IDD changes were histologically confirmed. Post-contrast MRI showed diseased nutritional diffusion patterns in the cement-blocked discs. Moreover, the degenerative changes of the cement-blocked discs exceeded those of the injured AF positive controls.

CONCLUSIONS

The endplate nutritional pathway was interfered with and diseased after three months of bone cement intervention in an immature porcine model. Severe interference in the endplate nutritional pathway in an immature porcine model caused IDD. These findings also draw attention to the fact that interference in endplate nutritional pathways in immature or young patients may affect the vitality of adjacent discs.

Factors regulating viable cell density in the intervertebral disc: blood supply in relation to disc height

The intervertebral disc is an avascular tissue, maintained by a small population of cells that obtain nutrients mainly by diffusion from capillaries at the disc-vertebral body interface. Loss of this nutrient supply is thought to lead to disc degeneration, but how nutrient supply influences viable cell density is unclear. We investigated two factors that influence nutrient delivery to disc cells and hence cell viability: disc height and blood supply. We used bovine caudal discs as our model as these show a gradation in disc height. We found that although disc height varied twofold from the largest to the smallest disc studied, it had no significant effect on cell density, unlike the situation found in articular cartilage. The density of blood vessels supplying the discs was markedly greater for the largest disc than the smallest disc, as was the density of pores allowing capillary penetration through the bony endplate. Results indicate that changes in blood vessels in the vertebral bodies supplying the disc, as well as changes in endplate architecture appear to influence density of cells in intervertebral discs.

Morphological changes of lumbar vertebral bodies and intervertebral discs associated with decrease in bone mineral density of the spine: a cross-sectional study in elderly subjects

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To investigate changes in the morphology of the lumbar vertebrae and intervertebral discs associated with osteoporosis of the spine in elderly subjects.

SUMMARY OF BACKGROUND DATA

Osteoporosis is a common condition that primarily affects the elderly with significant impact on quality of life. How exactly osteopenia and osteoporosis influence vertebral and intervertebral disc morphology remains unknown and needs exploration.

METHODS

A total of 395 community-dwelling ambulatory adults from 67 to 89 years of age were studied. The lumbar bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry. T2-weighted sagittal images of the lumbar spine were obtained using a 1.5-T magnet. For each subject, the anterior height (Ha), middle height (Hm), posterior height (Hp), and anterior-posterior (AP) dimension of the 5 lumbar vertebrae (L1-L5) and 6 intervertebral discs (T12-L1 to L5-S1) were measured. To minimize the age effect, volume of these vertebrae and discs was measured in subgroups of 47 men (mean age = 74 yr, range: 73-75 yr) and 67 women (mean age = 72 yr, range: 71-73 yr). Continuous variables were examined by analysis of covariance after adjustment of height and age.

RESULTS

There was no significant age difference between the groups of normal BMD, osteopenia, and osteoporosis. For the vertebral bodies, lower BMD was associated with a decrease of Ha, Hm, and Hp but not AP in both sexes, leading to an increased biconcavity index. For the discs, lower BMD was associated with a decrease of Ha and Hp, as well as AP, and an increase in Hm in both men and women. The disc biconvexity index was increased. Lower BMD is associated with an overall decrease in both vertebral volume and disc volume.

CONCLUSION

Lower BMD is associated with a decreasing trend in both lumbar vertebral and disc volumes in elderly subjects but an increase in the Hm of the intervertebral discs.

Seeing double: a comparison of microstructure, biomechanical function, and adjacent disc health between double- and single-layer vertebral endplates

STUDY DESIGN

Experimental and computational assessment of thickness, porosity, biomechanical behavior, and adjacent disc glycosaminoglycan content in double- and single-layer bony endplate samples harvested from human cadaver spines.

OBJECTIVE

To determine if the second layer of bone in double-layer vertebral endplates allows the superficial layer to achieve a more optimal balance between its biomechanical and nutritional functions.

SUMMARY OF BACKGROUND DATA

Proper disc health requires the endplate to balance opposing biomechanical and nutritional functions. Previous studies investigating endplate function report seeing double: some endplates have a second layer of bone. However, it remains unclear whether the second layer of bone has any functional advantage. Such information could shed light on the factors that protect against disc degeneration.

METHODS

Six lumbar spines were obtained from human cadavers (32-84 yr) and scanned with magnetic resonance imaging. Cylindrical cores that included the endplate and underlying trabecular bone were harvested from the center of the superior vertebral endplates (6 double- and 12 single-layer endplates) and imaged using micro-computed tomography. The thickness and porosity of the bony endplate layers were measured for each core. High-resolution finite element analysis was performed to assess biomechanical behavior. Glycosaminoglycan content within the adjacent nucleus tissue was quantified using the dimethylmethylene blue technique.

RESULTS

The superficial layer of the double-layer endplates was 50% thinner (P = 0.009) and tended also to be more porous than single-layer endplates. Strains were higher in thinner endplates; however, the second layer of bone in the double-layer endplates had a stiffening effect so that despite being thinner than single-layer endplates, the superficial layer of the double-layer endplates had a similar risk of damage. After adjusting for age, glycosaminoglycan content was significantly higher in the nucleus tissue adjacent to the double-layer endplates (P = 0.01).

CONCLUSION

Compared with single-layer endplates, double-layer endplates seem to permit a more optimal balance between endplate biomechanical and nutritional functions, and may therefore offer a significant protective factor against disc degeneration.

Morphology of the human vertebral endplate

It is presumed that poor intervertebral disc cell nutrition is a contributing factor in degeneration, and is exacerbated by vertebral endplate sclerosis. Yet, quantitative relationships between endplate morphology and degeneration are unavailable. We investigated how endplate bone microstructure relates to indices of disc degeneration, such as morphologic grade, proteoglycan content, and cell density. Intervertebral core samples [n = 96, 14 subjects, L1-L5 level, ages 35-85 (64 ± 16 years), degeneration grade 1 (n = 4), grade 2 (n = 32), grade 3 (n = 44), grade 4 (n = 10), grade 5 (n = 6)] that included subchondral bone, cartilage endplate, and adjacent nucleus were harvested from human cadaveric lumbar spines. The morphology of the vertebral endplate was analyzed using µCT and the adjacent nucleus tissue was collected for biochemical and cellular analyses. Relationships between vertebral endplate morphology and adjacent disc degeneration were analyzed. Contrary to the prevailing notion, vertebral endplate porosity increased between 50% and 130% and trabecular thickness decreased by between 20% and 50% with advancing disc degeneration (p < 0.05). We also observed that nucleus cell density increased (R(2)  = 0.33, p < 0.05) and proteoglycan content decreased (R(2)  = 0.47, p < 0.05) as the endplate became more porous. Our data suggest that endplate sclerosis is not a fundamental factor contributing to disc degeneration. Rather, the opposite was observed in our samples, as the endplate became progressively more porous with age and degeneration. Since ischemic disc cell behavior is commonly associated with degenerative change, this may be related to other factors such as the quality of vertebral capillaries, as opposed to decreased permeability of intervening tissues.

Degenerative endplate changes of the lumbosacral spine: dynamic contrast-enhanced MRI profiles related to age, sex, and spinal level

PURPOSE

To investigate differences in perfusion profiles between degenerative endplate marrow changes and normal vertebral marrow in relation to spinal level, age, and sex with dynamic contrast-enhanced magnetic resonance imaging (DCE MRI).

MATERIALS AND METHODS

Ninety-two consecutive patients referred for evaluation of low back pain or sciatica, without history of malignant or chronic disease, underwent conventional and DCE MRI of the lumbosacral spine. Fifty-two of them demonstrated degenerative endplate marrow changes. Regions of interest were placed on sites of normal marrow (group A) and degenerative changes (group B) on subtracted images. Fitted time-intensity curves (fTICs) were generated and evaluated for curve pattern. Both groups were stratified into upper (L1-L2) and lower (L3-I1) levels, males and females younger or older than 50 years. Perfusion parameters were calculated and statistically compared for both groups and subgroups. Receiver operator curve (ROC) analysis was also performed.

RESULTS

Two fTIC patterns were identified. Perfusion parameters of degenerative changes and normal marrow differed significantly, even when groups were stratified for spinal level, age, and sex (P < 0.05). A time to peak value >108 seconds was characteristic for degenerative changes with sensitivity 69.5% and specificity 84.6%.

CONCLUSION

DCE MRI profiles of degenerative endplate marrow changes of the lumbosacral spine differ significantly from normal marrow regardless of spinal level, age, or sex.