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.

     

Decoupling: what is it and does it really help increase consent to organ donation?

Although the notion of decoupling is simple and potentially controllable by organ donation requestors, evidence to date of its potential has been inconsistent. The impact of the timing of requests was analyzed using data from a study of organ donor-eligible patients and their families (N = 420), involving 9 trauma hospitals located in southwest Pennsylvania and northeast Ohio. In-depth interviews where conducted with family members, healthcare professionals, and organ procurement organization staff involved in the process. Only a weak effect was found for the impact of timing on the decision using a bivariate, correlational analysis. Moreover, we found that raising the issue before rather than after the pronouncement of death was most strongly associated with consent to donation. This effect disappeared after examining decoupling in relation to other factors. However, active consideration of the patient's donation wishes and a clear understanding of the families' initial inclination toward donation were associated with consent to organ donation.     

Clinical study to evaluate the safety and effectiveness of the Aesculap Activ-L? artificial disc in the treatment of degenerative disc disease

Background  

The objective of this clinical study is to evaluate the safety and effectiveness of the Activ-L Artificial Disc for treatment of single-level degenerative disc disease of the lumbar spine in patients who have been unresponsive to at least six months of prior conservative care. The hypothesis of the study is that the Activ-L Disc is non-inferior to the control (the Charité^? Artificial Disc [DePuy Spine] or ProDisc-L^? Total Disc Replacement [Synthes Spine]) with respect to the rate of individual subject success at 24 months. Individual subject success is a composite of effectiveness and safety.     

Hip structural geometry and incidence of hip fracture in postmenopausal women: what does it add to conventional bone mineral density?

Summary

Hip geometry measurements of outer diameter and buckling ratio at the intertrochanter and shaft of the hip dual energy X-ray absorptiometry (DXA) scan predicted incident hip fracture in postmenopausal women. These associations, independent of age, body size, clinical risk factors, and conventional areal bone mineral density, suggest hip geometry plays a role in fracture etiology and may aid in improving identification of older women at high fracture risk.

Introduction

This study examined whether hip geometry parameters predicted hip fracture independent of body size, clinical risk factors, and conventional femoral neck bone mineral density (aBMD) and whether summary factors could be identified to predict hip fracture.

Methods

We studied 10,290 postmenopausal women from the Women's Health Initiative. Eight thousand eight hundred forty-three remained fracture free during follow-up to 11 years of follow-up, while 147 fractured their hip, and 1,300 had other clinical fractures. Hip structural analysis software measured bone cross-sectional area, outer diameter, section modulus, average cortical thickness, and buckling ratio on archived DXA scans in three hip regions: narrow neck, intertrochanter, and shaft. Hazard ratios were estimated using Cox proportional hazards models for individual parameters and for composite factors extracted from principal components analysis from all 15 parameters.

Results

After adjustment for age, body size, clinical risk factors, and aBMD, intertrochanter and shaft outer diameter measurements remained independent predictors of hip fracture with hazard ratios for a one standard deviation increase of 1.61 (95% confidence interval (CI), 1.25–2.08) for the intertrochanter and 1.36 (95% CI, 1.06–1.76) for the shaft. Average buckling ratios also independently predicted incident hip fracture with hazard ratios of 1.43 (95% CI, 1.10–1.87) at the intertrochanter and 1.24 (95% CI, 1.00–1.55) at the shaft. Although two composite factors were extracted from principal components analysis, neither was superior to these individual measurements at predicting incident hip fracture.

Conclusions

Two hip geometry parameters, intertrochanter outer diameter and buckling ratio, predict incident hip fracture after accounting for clinical risk factors and aBMD.     

Laparoscopic surgery: does it increase the probability of atrial and ventricular arrhythmias in children?

PURPOSE: Despite the minor physiologic changes those occur during laparoscopic procedures, pneumoperitoneum with CO2 insufflation may induce alterations in electrocardiographic (ECG) variables, which may predict severe atrial and ventricular arrhythmias. This study aims to assess QT dispersion (QTD) and P wave dispersion (PWD) changes in children who have undergone laparoscopic appendectomy. PATIENTS AND METHODS: Sixteen patients (12 males and 4 females) who had preoperative diagnosis of appendicitis were included in the study. As laparoscopic exploration revealed appendicitis in all patients, laparoscopic appendectomy was performed. Preinsufflation (ECG1), postinsufflation (ECG2), predesufflation (ECG3), and postdesufflation (ECG4) ECGs were achieved at a speed of 25 mm/s for QTD and PWD analyses. RESULTS: Although mean corrected QTD and PWD at ECG2 and ECG3 were significantly greater than ECG1 and ECG4, those changes induced by insufflation of CO2 were reversible. CONCLUSIONS: The clinical significance of pneumoperitoneum, which causes an increase in corrected QTD and PWD in children, remains to be determined with further studies.     

Impact of patellar height on unicompartment knee arthroplasty: does patella baja lead to an inferior outcome?

Background

Though a number of series with long-term results have been published, there is still a paucity of literature on the role of patellar height after unicompartment knee arthroplasty (UKA). The present study was conducted with a hypothesis that patella baja may lead to a poor outcome at follow-up.

Materials and methods

A retrospective review of 134 knees was performed and patellar height calculated before and after UKA by Blackburne-Peel index (BPI) and the Insall-Salvati ratio (ISR) on true lateral radiographs of the patients in 30° of flexion taken pre-operatively and at 1 year, 2 years and final follow-up (minimum 5 years). Statistical analysis was performed to evaluate the outcomes.

Results

There was a decrease in ISR in 14.18 % and in BPI in 19.4 % at final follow-up. There was a significant decrease in BPI values while the decrease was not significant for ISR. After eliminating the pre-operative patella baja, 7.3 % developed post-operative patella baja, according to ISR, while 11.5 % developed patella baja as per BPI. At final follow-up there was a statistically significant decrease in stair climbing scores in patients with patella baja when compared to patients with normal ISR.

Conclusion

Patients with a decrease in patellar height as per ISR have a decrease in stair climbing score at mid-term follow-up while the overall KSS, and pain scores are not affected by a change in patellar height and neither is there a significant progress in patellofemoral osteoarthritis among patients with patella baja compared to normal patella.     

Abnormal stress concentrations in lumbar intervertebral discs following damage to the vertebral bodies: a cause of disc failure?

Summary The purpose of this investigation was to test the hypothesis that damage to a lumbar vertebral body can lead to abnormal stress concentrations in the adjacent intervertebral discs. Twenty-three cadaveric lumbar motion segments, from persons who had died aged between 19 and 87 years, were subjected to substantial compressive loading while in the neutral, lordotic and flexed postures. During the loading period, a miniature pressure transducer was pulled through the disc along its mid-sagittal diameter and graphs of horizontal and vertical compressive stress against distance were obtained. Measurements were repeated after each motion segment had been compressed up to the point of mechanical failure: at this point the vertebral bodies suffered minor damage to the trabecular arcades, and sometimes to the end-plate, but the structure remained essentially intact and motion segment height was reduced by only 1%–2%. After damage, the stress in the nucleus and anterior annulus fell by about 30%, and high stress peaks appeared in the inner posterior annulus. These changes were more pronounced in lordotic posture and less pronounced in flexion. The youngest discs showed the smallest changes. It is concluded that minor compressive damage to the vertebral body can lead to high stress concentrations in the posterior annulus. Since the vertebral body is the weak link of the lumbar spine, this may be a frequent precipitating cause of isolated disc failure in living people.AcroMed Prize of the European Spine Society 1992     

Comparison of Jack dilator-kyphoplasty and balloon-kyphoplasty in postoperative vertebral height loss and adjacent intervertebral disc degeneration北大核心CSCD

Objective To compare Jack dilator-kyphoplasty (DKP) and balloon-kyphoplasty (BKP) for osteoporotic vertebral compression fracture (OVCF) in postoperative vertebral height loss and adjacent intervertebral disc degeneration. Methods A total of 94 OVCF patients were treated and fully followed up at Department of Orthopaedic Surgery, The First Hospital Affiliated to Nanjing Medical University from May 2007 to October 2016. Of them, 30 were subjected to DKP and 64 to BKP. In DKP group, there were 18 males and 12 females, with an age of (72.4±9.2) years, a bone density of (-3.99±0.88) SD and a disease course of (0.7±0.4) months; in BKP group, there were 28 males and 36 females, with an age of (71.6±14.3) years, a bone density of (-4.08±0.63) SD and a disease course of (0.6±0.3) months. The 2 groups were compared in terms of change in the height of injured vertebrae, disc height index percentage (DHIP) and Pfirrmann grading of adjacent disc degeneration at preoperation, 2 days and 36 months after operation. Results The 2 groups were comparable due to insignificant differences in their preoperative general data (P>0.05). The anterior and middle heights of injured vertebrae and DHIP at postoperative 36 months were significantly lower than those at postoperative 2 days in both groups (P<0.05). There was no significant difference between the 2 groups in DHIP at 36 months after operation (79.86%±4.48% versus 80.24%±6.85%) (t=0.277, P=0.782). By the Pfirrmann grading, 36 and 84 patients had intervertebral disc degeneration in DKP and BKP groups respectively. There was no significant difference in the incidence of intervertebral disc degeneration between the 2 groups (60.0% versus 65.6%) (χ2=0.560, P=0.454). Conclusions In the OVCF treatment, DKP and BKP may potentially cause height loss of the injured vertebrae and degeneration of adjacent intervertebral disc, but no difference was found in disc degeneration between the 2 modes. © 2022 Authors. All rights reserved.     

Surgical outcomes of degenerative lumbar spondylolisthesis with anterior vacuum disc: Can the intervertebral cage overcome intradiscal vacuum phenomenon and enhance posterolateral fusion?

Background The vacuum phenomenon within an intervertebral disc is not an uncommon radiographic finding in the elderly. However, no reports in the English literature have focused on the effect of an anterior vacuum disc in relation to surgical outcome of same-segment spondylolisthesis. We hypothesized that instrumented posterolateral fusion is not adequate in this situation and that additional interbody fusion with cages would provide better radiographic and clinical outcomes.Methods The medical records of 72 patients who underwent instrumented fusion for one-segment degenerative lumbar spondylolisthesis with a vacuum disc were reviewed. Thirty-three patients were placed in the noncage group and 39 in the cage group based on whether or not augmentation with an intervertebral cage was carried out. Radiographic parameters (disc height, translation, intradiscal angle, segmental angle, and fusion) on preoperative, postoperative, and final radiographs were compared between groups. The Oswestry Disability Index (ODI) and Brosky criteria were used to evaluate clinical outcomes.Results Blood loss and operation time were greater in the cage group but without a significant difference (p = 0.271, p = 0.108, respectively). Preoperative radiographic data were similar between groups, but the cage group had more intradiscal lordosis, less translation, a higher disc height after surgery, and maintained these advantages at the final follow-up. In addition, the posterolateral fusion rate was significantly higher in the cage group (92.3 % vs. 56.1 %, p < 0.001), and they obtained more ODI improvement (30.62 vs. 26.39, p = 0.369) and a higher final satisfaction rate (79.5 % vs. 57.6 %, p = 0.044). There was no decrease in the incidence of developed adjacent segmental disease in the noncage group.Conclusions The vacuum sign at the spondylolisthesis segment should be regarded as another sign of instability. We suggest that instrumented posterolateral fusion simultaneous with intervertebral fusion with a cage can overcome this situation.