A Comparative MRI Study of Upper and Lower Lumbar Motion Segments in Patients With Low Back Pain

Obesity increases the odds of intervertebral disc herniation and spinal stenosis; an MRI study of 1634 low back pain patients

PURPOSE

The objective of this study was to examine the relationships between BMI and intervertebral disc degeneration (DD), disc herniation (DH) and spinal stenosis (SS) using a large, prospectively recruited and heterogeneous patient population.

METHODS

Patients were recruited through the European Genodisc Study. An experienced radiologist scored MRI images for DD, DH and SS. Multivariate linear and logistic regression analyses were used to model the relationship between these variables and BMI with adjustment for patient and MRI confounders.

RESULTS

We analysed 1684 patients with a mean age of 51 years and BMI of 27.2 kg/m2.
The mean DD score was 2.6 (out of 5) with greater DD severity with increasing age (R2 = 0.44). In the fully adjusted model, a 10-year increase in age and a 5 kg/m2 increase in BMI were associated, respectively, with a 0.31-unit [95% CI 0.29,0.34] and 0.04-unit [CI 0.01,0.07] increase in degeneration. Age (OR 1.23 [CI 1.06,1.43]) and BMI (OR 2.60 [CI 2.28,2.96]) were positively associated with SS. For DH, age was a negative predictor (OR 0.70 [CI 0.64,0.76]) but for BMI (OR 1.19 [CI 1.07,1.33]), the association was positive. BMI was the strongest predictor of all three features in the upper lumbar spine.

CONCLUSIONS

While an increase in BMI was associated with only a slight increase in DD, it was a stronger predictor for DH and SS, particularly in the upper lumbar discs, suggesting weight loss could be a useful strategy for helping prevent disorders associated with these pathologies.

Vertebral endplate defects are associated with bone mineral density in lumbar degenerative disc disease

PURPOSE

Evidence has shown that lumbar vertebral endplate defects are clinically relevant and closely related to disc degeneration, but the relationship between endplate defects and bone mineral density (BMD) remains unclear. This study aimed to explore the association between endplate defects and BMD-related values in patients with lumbar degenerative disc disease (LDD).

METHODS

Three hundred and twenty-five Chinese adult subjects diagnosed with LDD underwent dual energy X-ray absorptiometry. Endplate defects were classified using lumbar MRI. Groups were subdivided based on the occurrence rates of defect endplates. BMD at the lumbar vertebral and bilateral femur necks was compared between groups, and the association between endplate defects and lumbar BMD-related values was analyzed and adjusted for confounders including age, sex, serum levels of 25-hydroxy vitamin D (25(OH)D), calcium (Ca) and phosphorus (P).

RESULTS

Of 325 patients and 3250 endplates, 59.72% had defects, and 188 patients were divided into the higher defect rate group (occurrence rate > 50%). The higher defect rate group was associated with older age, more common postmenopausal females, higher osteoporosis rates and lower serum Ca and P levels. Lumbar BMD was greater than that at bilateral femur necks and was not equal to osteoporosis diagnosis. Endplate defects were more prevalent in lower segments. The occurrence of endplate defects was positively associated with lumbar BMD-related values in the partial correlation analysis. The association between endplate defects and lumbar BMD varies for subtypes and segments, with a trend of positive association in rim and erosive subtypes after adjusting for confounders.

CONCLUSIONS

The present study demonstrated that the occurrence of endplate defects was associated with greater lumbar BMD values in patients with LDD. This association varies for different defect subtypes and segments. The results indicated that endplate defects should be taken into consideration in osteoporosis treatment to alleviate disc degeneration.

Smoking and degenerative spinal disease: A systematic review

Smoking is a major cause of morbidity and mortality worldwide and is responsible for the death of more than 8 million people per year globally. Through a systematic literature review, we aim to review the harmful effects of tobacco smoking on degenerative spinal diseases (DSD). DSD is a debilitating disease and there is a need to identify if smoking can be an attributable contender for the occurrence of this disease, as it can open up avenues for therapeutic options. Sources such as PubMed and Embase were used to review literature, maintaining tobacco smoking and spinal diseases as inclusion factors, excluding any article that did not explore this relationship. Risk of bias was assessed using analysis of results, sample size and methods and limitations. Upon review of the literature, tobacco smoking was found to be a major risk factor for the occurrence of DSDs, particularly lumbar spinal diseases. Smokers also experienced a greater need for surgery and greater postoperative wound healing complications, increased pain perception, delay in recovery and decreased satisfaction after receiving surgery. These effects were noted along the entire spine. Many mechanisms of action have been identified in the literature that provide plausible pictures of how smoking leads to spinal degeneration, exploring possible primary targets which can open up opportunities to develop potential therapeutic agents. More studies on cervical and thoracic spinal degeneration would be beneficial in identifying the effect of nicotine on these spinal levels. Some limitations included insufficient sample size, inconclusive evidence and lack of sufficient repeat studies. However, there appears to be a sufficient amount of research on smoking directly contributing to lumbar spinal pathology.

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Smoking is a risk factor for the occurence of degenerative spinal disease (DSD).

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There are numerous pathological mechanisms attributed to spinal pathology by smoking.

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Smoking appears to be a significant risk factor for lumbar DSDs, with smoke studies also suggesting its role in cervical DSDs.

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There is insufficient research on the effect of smoking on the thoracic spine.

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Smoking leads to worse outcomes and potential complications post-surgery, as well as increased pain perception and poorer subjective response post-surgery.

The association between occupational loading and spine degeneration on imaging - a systematic review and meta-analysis

Background

There are inconsistencies in findings regarding the relationship of occupational loading with spinal degeneration or structural damage. Thus, a systematic review was conducted to determine the current state of knowledge on the association of occupational loading and spine degeneration on imaging.

Methods

We performed electronic searches on MEDLINE, CINAHL and EMBASE. We included cross-sectional, case control and cohort studies evaluating occupational loading as the exposure and lumbar spine structural findings on imaging as the outcomes. When possible, results were pooled.

Results

Seventeen studies were included in the review. Ten studies evaluated the association of occupational loading with disc degeneration (signal intensity), four of which were pooled into a meta-analysis. Of the 10 studies, only two did not identify a relationship between occupation loading and disc degeneration. A meta-analysis including four of the studies demonstrated an association between higher loading and degeneration for all spinal levels, with odds ratios between 1.6 and 3.3. Seven studies evaluated disc height narrowing and seven evaluate disc bulge, with six and five identifying an association of loading and with imaging findings respectively. Three studies evaluated modic changes and one identified and association with occupational load.

Conclusions

There was moderate evidence suggesting a modest association between occupational loading and disc degeneration (signal intensity), and low-quality evidence of an association between occupational loading and disc narrowing and bulging.

Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain

OBJECTIVE

To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients.

METHODS

Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP.

RESULTS

Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP.

CONCLUSION

The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients.

KEY POINTS

• The location of vertebral endplate signal changes supports a mechanical aetiology. • Several sacroiliac joint findings were associated with female gender and pregnancy-related back pain. • Sacroiliac joint bone marrow oedema was frequent and age-associated, indicating a possible degenerative aetiology. • More knowledge of the clinical importance of sacroiliac joint MRI findings is needed.

ALIF and total disc replacement versus 2-level circumferential fusion with TLIF: a prospective, randomized, clinical and radiological trial

STUDY DESIGN

Prospective, randomized trial.

PURPOSE

The treatment of degenerative disc disease (DDD) with two-level fusion has been associated with a reasonable rate of complications. The aim of the present study was to compare (Hybrid) stand-alone anterior lumbar interbody fusion (ALIF) at L5/S1 with total disc replacement at L4/5 (TDR) as an alternative surgical strategy to (Fusion) 2-level circumferential fusion employing transforaminal lumbar interbody fusion (TLIF) with transpedicular stabilization at L4-S1.

METHODS

A total of 62 patients with symptomatic DDD of segments L5/S1 (Modic ≥2°) and L4/5 (Modic ≤2°; positive discography) were enrolled; 31 were treated with Hybrid and 31 with Fusion. Preoperatively, at 0, 12, and a mean follow-up of 37 months, clinical (ODI, VAS) and radiological evaluations (plain/extension-flexion radiographs evaluated for implant failure, fusion, global and segmental lordosis, and ROM) were performed.

RESULTS

In 26 of 31 Hybrid and 24 of 31 Fusion patients available at the final follow-up, we found a significant clinical improvement compared to preoperatively. Hybrid patients had significantly lower VAS scores immediately postoperatively and at follow-up compared to Fusion patients. The complication rates were low and similar between the groups. Lumbar lordosis increased in both groups. The increase was mainly located at L4-S1 in the Hybrid group and at L1-L4 in the Fusion group. Hybrid patients presented with increased ROM at L4/5 and L3/4, and Fusion patients presented with increased ROM at L3/4, with significantly greater ROM at L3/4 compared to Hybrid patients at follow-up.

CONCLUSIONS

Hybrid surgery is a viable surgical alternative for the presented indication. Approach-related inferior trauma and the balanced restoration of lumbar lordosis resulted in superior clinical outcomes compared to two-level circumferential fusion with TLIF.

[Review of dose-response relationship between low level vibration and lower back pain]

OBJECTIVES

Whole-body vibration (WBV) with high level acceleration is found in the workplaces of construction and mining, and has been reported to be associated with low back pain (LBP) experienced by operators of heavy vehicles as an occupational health problem. Because the work conditions with exposure to WBV include bending and twisting of the low back and other factors, the causal relationship between WBV and LBP has not yet been affirmed. A review suggesting the dose-response relationship between WBV with low acceleration and LBP has been published, although there is little evidence supporting the causal relationship. Therefore, we reviewed the dose-response relationship between WBV with low acceleration and LBP.

METHODS

We examined original articles which reported a dose-response relationship between WBV and LBP in addition to review articles with almost the same aims.

RESULTS AND DISCUSSION

Studies which examined imaging findings such as CT and MRI, objective indicators of LBP, do not confirm the causal relationship. Although many studies demonstrated a positive relationship between working periods and incidence of LBP, there were very few reports which recognized a dose-response relationship for the vibration acceleration below 1.0 m/s(2) in which the 8-h energy-equivalent, combined frequency-weighted vibration of three diagonal, that is x, y and z, axes (root-sum-of-squares), Asum(8) was used as an index of vibration exposure.

CONCLUSION

This paper reject the hypothesis of a dose-response relationship between WBV with low acceleration and LBP, concluding there is no evidence linking low level exposure to WBV with LBP for the Japan Society for Occupational Health to recommend 0.35 m/s(2)/as of Asum(8) as a tentative occupational exposure limits for WBV.

Whole-body vibration: is there a causal relationship to specific imaging findings of the spine?

STUDY DESIGN

Systematic review.

OBJECTIVE

To perform a systematic review of the available literature for those studies that evaluated the role of whole-body vibration (WBV) on the spine, using imaging modalities as well as an estimation of WBV exposure.

SUMMARY OF BACKGROUND DATA

Numerous comparative studies have reported a possible association between the occurrence of spinal symptoms and exposure to WBV. These exposures have commonly been examined in the work environment largely through self-reported questionnaires only. From a scientific perspective, the majority of studies emphasize symptoms and lack objective medical evidence, such as spinal imaging, to help establish a specific spinal disorder. Because both neck and low back pain comprise symptoms that can arise from a host of factors including age, a casual link between spinal disorders and WBV cannot be affirmed.

METHODS

MEDLINE and EMBASE were searched for studies related to WBV and spinal symptoms, diagnosis, and/or disorders. Our searches were limited to studies published prior to August 2011. The resulting 700 citations (after excluding 354 duplicates) were then screened by 3 independent reviewers on the basis of the following predetermined inclusion and exclusion criteria: inclusion-clinical studies with imaging evaluation (radiographs, computed tomographic scans, and/or magnetic resonance images) and documented WBV exposure (occupation, amount of WBV, and/or duration); exclusion-reliance solely on self-reporting of symptoms (neck pain, low back pain, and/or sciatica), those articles based on a clinical diagnosis without use of imaging, and in vitro/animal/biomechanical studies.

RESULTS

Only 7 studies met the inclusion criteria for this systematic review. Included were 5 retrospective cohort and 2 cross-sectional studies. Although mixed results and conclusions were found, the majority of studies did not identify an association between WBV exposure and an abnormal spinal imaging finding indicating damage of the spine. We should also stress that each included study has limitations secondary to quantifying WBV exposure accurately, both as a single encounter and as a total exposure over years.

CONCLUSION

Based on our results from this systematic review, no causality can be shown between WBV and abnormal spinal imaging findings. With the conflicting data available in the literature, WBV has not been established as a cause for objective spinal pathological changes on a scientific basis.

Brief daily exposure to low-intensity vibration mitigates the degradation of the intervertebral disc in a frequency-specific manner

Hindlimb unloading of the rat causes rapid hypotrophy of the intervertebral disc (IVD) as well as reduced IVD height and glycosaminoglycan content. Here we tested the hypothesis that low-intensity mechanical vibrations (0.2 g), as a surrogate for exercise, will mitigate this degradation. Four groups of Sprague-Dawley rats (4.5 mo, n = 11/group) were hindlimb unloaded (HU) for 4 wk. In two of the HU groups, unloading was interrupted for 15 min/day by placing rats in an upright posture on a platform that was vertically oscillating at 45 or 90 Hz (HU+45, HU+90). Sham control rats stood upright on an inactive plate for 15 min/day (HU+SC). These three experimental groups were compared with HU uninterrupted by weightbearing (HU) and to normally ambulating age-matched controls. In the HU and HU+SC rats, 4 wk of unloading resulted in a 10% smaller IVD height, as well as less glycosaminoglycan in the whole IVD (7%) and nucleus pulposus (17%) and a greater collagen-to-glycosaminoglycan ratio in the whole IVD (17%). Brief daily exposure to 90 Hz mechanical oscillations mitigated this degradation; compared with HU ± SC, the IVD of HU+90 had an 8% larger height and greater glycosaminoglycan content in the whole IVD (12%) and nucleus pulposus (24%). In contrast, the 45 Hz signal failed to mitigate changes in height or glycosaminoglycan content brought with altered spinal loading, but normalized the collagen-to-glycosaminoglycan ratio to levels observed in age-matched controls. In summary, unloading caused marked phenotypic and biochemical changes in the IVD, a deterioration that was not slowed by brief weightbearing. However, low-intensity 90 Hz vibrations superimposed on weightbearing largely preserved the morphology and biochemistry of the IVD and suggest that these biomechanically based signals may help protect the IVD during long bouts of nonambulation.