Gut-disc axis: A cause of intervertebral disc degeneration and low back pain?

Purpose

Low back pain (LBP), a widely prevalent and costly disease around the world, is mainly caused by intervertebral disc (IVD) degeneration (IDD). Although numerous factors may trigger this degenerative process, microbiome dysbiosis has recently been implicated as one of the likely causes. However, the exact relationship between the microbiome and IDD is not well understood. This review summarizes the potential mechanisms and discusses microbiome dysbiosis’s possible influence on IDD and LBP.

Methods

Prospective literature review.

Results

Alterations in microbiome composition and host responses to the microbiota causing pathological bone development and involution, led to the concept of gut-bone marrow axis and gut-bone axis. Moreover, the concept of the gut-disc axis was also proposed to explain the microbiome’s role in IDD and LBP. According to the existing evidence, the microbiome could be an important factor for inducing and aggravating IDD through changing or regulating the outside and inside microenvironment of the IVD. Three potential mechanisms by which the gut microbiota can induce IVD and cause LBP are: (1) translocation of the bacteria across the gut epithelial barrier and into the IVD, (2) regulation of the mucosal and systemic immune system, and (3) regulation of nutrient absorption and metabolites formation at the gut epithelium and its diffusion into the IVD. Furthermore, to investigate whether IVD is initiated by pathogenic bacteria and establish the correlation between the presence of certain microbial groups with the disease in question, microbiome diversity analysis based on16S rRNA data can be used to characterise stool/blood microbiota from IVD patients.

Conclusion

Future studies on microbiome, fungi and viruses in IDD is necessary to revolutionize our thinking about their possible role in the development of IVD diseases. Furthermore, we believe that inflammation inhibition and interruption of amplification of cascade reaction in IVD by targeting the gut and IVD microbiome is worthwhile for the treatment of IDD and LBP.

Level of Evidence I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

     

Low back pain intervention: conservative or surgical?

Low back pain (LBP) is a very common disorder with a U.S. population incidence of 80%. The risk for developing chronic LBP is relatively low but the majority of the costs associated with LBP are generated specifically by this group. Unfortunately, there is no gold standard intervention and few comparative, randomized, prospective treatment studies have been done. Therefore, the optimal treatment approach continues to be controversial. Surgery is usually reserved for those patients with severe and debilitating symptoms and, with careful selection, can result in good outcomes with rapid return to function. For patients who are not surgical candidates, conservative treatment must emphasize restoration and maintenance of functional movement.     

Preventive interventions for back and neck pain problems: what is the evidence?

STUDY DESIGN: A review of controlled trials. OBJECTIVES: To determine which interventions are used to prevent back and neck pain problems as well as what the evidence is for their utility. SUMMARY OF BACKGROUND DATA: Given the difficulty in successfully treating long-term back and neck pain problems, there has been a call for preventive interventions. Little is known, however, about the value of preventive efforts for nonpatients, e.g., in the general population or workplace. METHODS: The literature was systematically searched to locate all investigations that were: 1) specifically designed as a preventive intervention; 2) randomized or nonrandomized controlled trials; and, 3) using subjects not seeking treatment. Outcome was evaluated on the key variables of reported pain, report of injury, dysfunction, time off work, health-care utilization, and cost. Conclusions were drawn using a grading system. RESULTS: Twenty-seven investigations meeting the criteria were found for educational efforts, lumbar supports, exercises, ergonomics, and risk factor modification. For back schools, only one of the nine randomized trials reported a significant effect, and there was strong evidence that back schools are not effective in prevention. Because the randomized trials concerning lumbar supports were consistently negative, there is strong evidence that they are not effective in prevention. Exercises, conversely, showed stable positive results in randomized controlled trials, giving consistent evidence of relatively moderate utility in prevention. Because no properly controlled trials were found for ergonomic interventions or risk factor modification, there was not good quality evidence available to draw a conclusion. CONCLUSIONS: The results concerning prevention for subjects not seeking medical care are sobering. Only exercises provided sufficient evidence to conclude that they are an effective preventive intervention. There is a dire lack of controlled trials examining broad-based multidimensional programs. The need for high quality outcome studies is underscored.     

Artificial disc replacement: the new solution for discogenic low back pain?

As we develop an increased understanding of DDD (e.g., pain generators, natural history, associated facet disease), so too will our ability to provide patients with effective care increase. Cautious optimism should be the attitude of surgeons treating patients with ADR. Issues such as implant design, wear debris, the role of ADR in osteoporosis, revision strategies, the patient selection will play important roles in the clinical success of ADR. the various topics discussed in this text will require careful additional scientific scrutiny prior to unconstrained endorsement of this evolving technique.     

Side of symptomatic annular tear and site of low back pain: is there a correlation?

STUDY DESIGN: A retrospective chart review. OBJECTIVES: To report the correlation between the side of a concordantly painful, post-discography computer tomography (CT) visualized, annular tear, and the side of a patients' low back pain. SUMMARY OF BACKGROUND DATA: An annular fissure extending from the nucleus to the outer one-third of the annulus is thought to be the nociceptive source stimulated during provocative lumbar discography. To our knowledge, there are no studies that have attempted to delineate whether the side of the annular tear correlates with the side of the patient pain. METHODS: One hundred and one post-discography CT scans, performed on patients with single level, concordantly painful, and fissured discs identified during lumbar discography, were randomly obtained from the archived and current files of the Penn Spine Center's film library. These were reviewed by both the lead author and a spine radiologist, both of who were blinded to the side of the patients pain, to determine which scans demonstrated clearly definable tears extending to the outer one-third of the annulus. Statistical analysis via the exact method was used to determine the correlation between the side of the patients tear and the side of the patients pain. RESULTS: Forty post-discography CT scans met the inclusion criteria. There was a random correlation between the side of the patients concordantly painful annular tear and the side of the patients pain. CONCLUSIONS: The results of this study raise several questions regarding the embryologic development of the intervertebral disc and its somite, neurologic transmission of discogenic pain, distribution of chemical inflammagens, validity of discography, technique of ESI, and technique and validity of IDET.     

Backpacks and back pain: where's the epidemic?

The purpose of this study was to determine if children presenting with a chief complaint of back pain at a pediatric orthopedic office attribute their pain to wearing a heavy backpack. A retrospective medical records search was performed to identify school-age patients with back pain. Of the 346 patients included in this study, only 1 child attributed back pain to wearing a backpack. Three patients stated that their back pain was made worse by carrying their backpack. A phone survey revealed that 80% of the patients in this study wore a backpack for school purposes. The authors found that school-age children with back pain severe enough to require orthopedic evaluation rarely attribute their pain to wearing a backpack.     

"Low back pain"--下腰痛?腰痛?

“Low back pain”一词在国内绝大多数译文或译著中被译为“下腰痛”,也有作者将其译为“下背痛”。笔者认为这些译法不妥,曲解了“low back pain”的原意。此词翻译的关键在于对“low back”一词解剖部位的理解上。在英文中,“back”一词在解剖上指“背,背部,躯干从颈至骨盆的     

Xenotransplantation: back to the future?

The field of xenotransplantation has fluctuated between great optimism and doubts over the last 50 years. The initial clinical attempts were extremely ambitious but faced technical and ethical issues that prompted the research community to go back to preclinical studies. Important players left the field due to perceived xenozoonotic risks and the lack of progress in pig‐to‐nonhuman‐primate transplant models. Initial apparently unsurmountable issues appear now to be possible to overcome due to progress of genetic engineering, allowing the generation of multiple‐xenoantigen knockout pigs that express human transgenes and the genomewide inactivation of porcine endogenous retroviruses. These important steps forward were made possible by new genome editing technologies, such as CRISPR/Cas9, allowing researchers to precisely remove or insert genes anywhere in the genome. An additional emerging perspective is the possibility of growing humanized organs in pigs using blastocyst complementation. This article summarizes the current advances in xenotransplantation research in nonhuman primates, and it describes the newly developed genome editing technology tools and interspecific organ generation.     

Does elite swimming accelerate lumbar intervertebral disc degeneration and increase low back pain? A cross-sectional comparison

Purpose

The aim was to elucidate elite swimming’s possible influence on lumbar disc degeneration (DD) and low back pain (LBP).

Methods

Lumbar spine MRI was performed on a group of elite swimmers and compared to a matched Finnish population-based no-sport group.

Results

One hundred elite swimmers and 96 no-sport adults, mean age 18.7/20.8, respectively, participated. Overall, the two groups had similar prevalence of DD. Swimmers had more DD in the upper lumbar spine but tended to have less DD at the lowest level. Prevalence of bulges and disc herniations were similar, but swimmers had significantly more bulges at L4–5. The swimmers reported less LBP, although not significantly (N.S.). If degenerative findings were present, the association between them and LBP was stronger in the no-sport group.

Conclusion

Elite swimmers and controls had similar prevalence of DD and LBP, although the pattern of DD differed between the groups. In case of DD, swimmers reported less LBP, although N.S.

     

Low back pain: what determines functional outcome at six months? An observational study

Background  

The rise in disability due to back pain has been exponential with escalating medical and societal costs. The relative contribution of individual prognostic indicators to the pattern of recovery remains unclear. The objective of this study was to determine the prognostic value of demographic, psychosocial, employment and clinical factors on outcome in patients with low back pain     

Do number of days with low back pain and patterns of episodes of pain have similar outcomes in a biopsychosocial prediction model?

Purposes

We used two different methods to classify low back pain (LBP) in the general population (1) to assess the overlapping of individuals within the different subgroups in those two classifications, (2) to explore if the associations between LBP and some selected bio-psychosocial factors are similar, regardless which of the two classifications is used.

Method

During 1 year, 49- or 50-year-old people from the Danish general population were sent fortnightly automated text messages (SMS-Track) asking them if they had any LBP in the past fortnight. Responses for the whole year were then classified into two different ways: (1) In relation to the number of days with LBP in the preceding year (0, 1–30, and >30), (2) In relation to the frequency and duration of episodes of LBP (more or less never pain, episodic, and more or less constant pain). Some bio-psychosocial factors, collected with a questionnaire at baseline 9 years earlier, were entered into regression models to investigate their associations with the subgroups of the two classifications of LBP and the results compared.

Results

The percentage of agreement between categories of the two classification systems was above 68 % (Kappa 0.7). Despite the large overlap of persons in the two classification groups, the patterns of associations with the two types of LBP definitions were different in the two classification groups. However, none of the estimates were significantly different when the variables were compared across the two classifications.

Conclusion

Different classification systems of LBP are capable of bringing forth different findings. This may help explain the lack of consistency between studies on risk factors of LBP.

     

Discography: can pain in a morphologically normal disc be due to an adjacent abnormal disc?

Symptomatic patients who had Magnetic Resonance Imaging findings of degenerative disc disease and who failed conservative treatment were identified. As a preoperative test, these patients underwent discography. The patients, who experienced pain with injection into a morphologically normal disc adjacent to a morphologically abnormal disc, were included in the study. These patients subsequently had repeat discograms, during which the adjacent abnormal disc was first anesthetized with 2% lidocaine and the discogram was repeated at the adjacent normal level. All patients were blinded as to the nature of the procedure. Nine patients were identified (7 males and 2 females). The average age was 46.5 years (32–68). Two patients had a previous L4-Sacrum anterior and posterior fusion while 2 patients had L5-Sacrum anterior and posterior fusions. These four patients had solid fusions on Computerized Tomography scan and had developed adjacent segment degeneration according to MRI. Overall, each patient underwent an average of four discograms, at the lowest mobile disc segments. All of the patients were found to have a painful but morphologically normal disc adjacent to a painful and morphologically abnormal disc. The morphologically abnormal disc was anesthetized and the discography repeated on the normal disc. Upon this repeat discography, none of the patients experience any pain. The authors recommend anesthetizing painful abnormal discs prior to discography of the adjacent discs. This technique may avoid unnecessary dismissal of patients from treatment because of an appropriate response to discography. The normal disc may be due to referred pain from an adjacent abnormal disc.