Intradiscal methylene blue injection for the treatment of chronic discogenic low back pain

Correlation between sagittal morphology of lower lumbar end plate and degenerative changes in patients with lumbar disc herniation

Objective

As an important anatomic factor in the process of lumbar disc herniation (LDH), the correlation between end plate sagittal morphology and intervertebral disc degeneration (IDD) is unclear. Moreover, research on imaging data of lumbar end plate in patients with LDH is still insufficient. Our study aimed to observe the morphological change of the lower lumbar end plate (L3-S1) in patients with LDH on magnetic resonance imaging (MRI) and analyze its correlation with the degree of IDD.

Materials and Methods

A total of 116 patients were included in the study. Based on their MRI, we divided end plates into three types (concave, flat, and irregular), assigned intervertebral discs with Grade I-V given 1-5 points successively according to the Pfirrmann system, and determined whether there was Modic change of each end plate. The correlation between the morphology of the end plate and the degree of IDD was analyzed.

Results

There was an excellent interobserver agreement for each item we analyzed (interclass correlation coefficient >0.75). Concave end plate appeared most frequently (187, 53.7%) and was mainly distributed in L3/4 and L4/5, whereas irregular end plate was the least common type (54, 15.5%) and mainly concentrated in L5/S1. The IDD degree of the corresponding disc increased gradually from concave (3.27 ± 0.81) to irregular end plates (4.25 ± 0.79) (P < 0.05). Irregular end plates were more likely to have Modic changes than concave and flat end plates (P < 0.05).

Conclusion

The sagittal morphology of the lower lumbar end plate is related to modic changes and degree of IDD (based on the Pfirrmann grading system) in patients with LDH, and the concave end plate mostly reflects a lower degree of lumbar disc degeneration, which has substantial clinical significance.

Intradermal methylene blue analgesic application in posthemorrhoidectomy pain management: a randomized controlled trial

Introduction

Unbearable post-hemorrhoidectomy pain is a well-documented challenge, significantly impacting patient well-being and satisfaction after surgery, often influencing patients to decline in undergoing this procedure. It is widely recognized that methylene blue has an effect of reducing inflammation and pain by reduces the production of nitric oxide and inhibiting the action potentials production in nerves. This study aims to explore the potential benefits of postoperative regional administration of methylene blue in providing extended relief from post-hemorrhoidectomy pain.

Methods

This study included 97 patients aged 18-75 undergoing hemorrhoidectomy for stage III or IV hemorrhoids. A double-blind, randomized controlled trial compared postoperative intradermal injections of 1% methylene blue to 0.5% Marcaine as the control group. Two-week follow-up assessed pain. Statistical analysis, adherence to ethical standards, and registration were conducted.

Result

No significant differences were found in baseline demographics, surgical parameters, or complications between the Methylene Blue and control groups. Intervention group remained lower in mean pain score until the 12th day. Methylene blue group reported significantly lower postoperative pain scores from days 1 to 7, with no significant differences afterward.

Conclusion

This ongoing randomized controlled trial reveals the potential analgesic benefits of intradermal injection 1% methylene blue. It demonstrates comparable efficacy in reducing post-hemorrhoidectomy pain, with negligible side effects and complications.

Efficacy of stepped care treatment for chronic discogenic low back pain patients with Modic I and II changes

Objective

This study investigated whether patients with Modic changes (MC) of types I, I/II, and II would respond to an anti-inflammatory-based, stepped care treatment with three treatment steps: first, oral administration of NSAIDs, 2 × 200 mg celecoxib daily for two weeks; second, an intradiscal steroid injection (ID) with dexamethasone and cefazolin; and third, oral treatment with antibiotics (AB), 3 × 1 g amoxicillin daily for 100 days.

Design

This was an observational clinical study based on analyses of categorical data of patient-reported outcome measurements.

Subjects

Subjects were consecutive patients with chronic low back pain (CLBP), diagnosed by assessment of anamnestic signs of inflammation; a pain score ≥6 on the Numeric Pain Rating Scale (NPRS); a mechanical assessment; MC I, I/II, or II based on MRI; and lack of response to conservative treatment.

Methods

From January 1, 2015, to December 31, 2021, 833 eligible patients were selected for the stepped care treatment. A total of 332 patients completed requested follow-up questionnaires at baseline and 12 months (optional at 3 and 6 months). Primary outcomes were pain (at least 50 % pain relief) and/or a minimum of 40 % improvement in functionality as measured by the Roland Morris Disability Questionnaire (RMDQ) or the Oswestry Disability Questionnaire (ODI). Secondary outcome measures were use of pain medication and return to work.

Results

At 1 year of follow-up, 179 (53.6 %) of 332 patients reported improvement according to the responder criteria. Of the 138 patients that had received only NSAIDs, 88 (63.8 %) had improved. In addition, 50 (56.8 %) of the 183 patients that had received ID had improved, and 41 (38.7 %) of the 106 patients treated with AB had improved. None of the patients reported complications. 12.0 % of patients using AB stopped preterm due to undesirable side effects.

Conclusion

Treatment with a stepped care model for inflammatory pain produced clinically relevant, positive reported outcomes on pain and/or function. Our stepped care model appears to be a useful, safe, and cost-saving treatment option that is easily reproducible. Further studies, including randomized controlled trials and analyses of subgroups, may help to develop a more patient-tailored approach and further avoidance of less-effective treatments and costs.

Patent blue versus methylene blue and indigo carmine as a better dye for chromodiscography: in vitro staining efficacy and cytotoxicity study using bovine coccygeal intervertebral discs

BACKGROUND CONTEXT

Chromodiscography is an integral part of full-endoscopic discectomy (FED), comprising ordinary discography with radiopacity produced by contrast medium and intradiscal stain for visualizing annular defects in the endoscopic field. Nevertheless, concerns remain about the cytotoxicity of the stains used. The study of their staining efficacy is also lacking.

PURPOSE

To evaluate the feasibility of methylene blue, patent blue, and indigo carmine for intradiscal injection, investigate the effectiveness of each dye, and define critical concentration with adequate staining efficacy and tolerable cytotoxicity for use in chromodiscography during FED.

STUDY DESIGN

An experimental in vitro study.

METHODS

Dye stock solutions were prepared from powder. The stock was diluted with culture medium or balanced saline and used for cytotoxicity or intervertebral disc staining assays, respectively. Bovine tails were obtained from the local slaughterhouse and functional spine units of intervertebral discs were acquired by transverse incision at the disc level. Each disc was punctured over the posterolateral aspect using a surgical knife to simulate an annular defect. The intradiscal injection was performed with each dye at different concentrations using a 22G needle from the contralateral aspect of the punctured site. Staining efficacy was quantified using ImageJ software. Primary cells of bovine tails were cultivated in each dye at different concentrations. Cytotoxicity was assessed 24 hours after stain exposure using the CCK-8 toxicity assay.

RESULTS

Staining efficacy and cytotoxicity were proportional to the concentration of tested dyes. Lower limits of concentration producing significant staining efficacy of indigo carmine, methylene blue, and patent blue were 0.25 mg/mL, 0.25 mg/mL, and 0.05 mg/mL, respectively. Compared with controls, concentrations showing significant toxicity for indigo carmine, methylene blue, and patient blue were 1 mg/mL, 0.5 mg/mL, and 2.5 mg/mL, respectively.

CONCLUSIONS

Patent blue can serve as a more suitable tissue stain than either indigo carmine or methylene blue due to the widest range of tradeoff concentration within 0.05 to 2.5 mg/mL.

CLINICAL SIGNIFICANCE

Patent blue with the characteristic of good staining efficacy and lower cytotoxicity may be a promising option for chromodiscography during FED.

Methylene Blue Combined with Ropivacaine for Intercostal Nerve Block After Autologous Costal Cartilage Removal in Juvenile Patients

OBJECTIVES

Autologous costal cartilage is commonly used as a graft material in plastic surgery. However, after autologous costal cartilage removal, the pain at the surgical site is particularly strong. We conducted this controlled clinical study to verify the efficacy of methylene blue (MB) in intercostal nerve block after autologous costal cartilage removal and to provide a reference for the application of MB in postoperative analgesia after autologous costal cartilage removal.

METHODS

In this study, 90 adolescent patients with congenital microtia who underwent autologous rib cartilage graft for auricular reconstruction were randomly allocated to one of three groups (Group A: intercostal nerve block was performed with 0.75% ropivacaine; Group B: intercostal nerve block was performed with 1% MB; and Group C: intercostal nerve block was performed with 1% MB and 0.75% ropivacaine mixture). Two trained researchers observed and recorded the pain status of the children at 6 hours (T1), 24 hours (T2), 48 hours (T3), and 72 hours (T4) after surgery, respectively. Numerical rating pain scale (NRS) was used for scoring. And adverse reactions such as nausea, vomiting, and skin itching were recorded.

RESULTS

In this study, there was no statistical difference in age and gender of patients in Groups A, B, and C (P >0.05). In terms of NRS comparison, 6 hours after operation (T1), Group B > Group A > Group C (P< 0.05); 24 hours after operation (T2), Group B > Group A > Group C (P< 0.05); 48 hours after operation (T3), Group B > Group A > Group C (P< 0.05); 72 hours after operation (T4), Group A > Group B > Group C (P< 0.05). There were no statistically significant differences in postoperative nausea, vomiting, and skin itching among the three groups (P>0.05).

CONCLUSION

The analgesic effect of IV self-controlled analgesia combined with ropivacaine is quick, but the maintenance time is short. The analgesic effect of IV self-controlled analgesia combined with MB is slow to onset but long to maintain. The analgesic effect of IV self-controlled analgesia combined with MB and ropivacaine mixture is quick and maintained for a long time. Therefore, in patients after removal of costal cartilage, we recommend the analgesic treatment method of IV self-controlled analgesia combined with MB and ropivacaine mixture.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 . Special Topic.

Efficacy Analysis of Percutaneous Endoscopic Spinal Surgery for Young Patients with Discogenic Low Back Pain

Purpose

To evaluate the application value of percutaneous endoscopic spinal surgery for young patients with discogenic low back pain (DLBP) and to judge its clinical efficacy.

Methods

We retrospectively analyzed young patients with single-segment discogenic lumbago from July 2018 to June 2020 in our department who underwent percutaneous endoscopic surgery according to the inclusion and exclusion criteria. We finally enrolled 20 patients. The follow-up time was 6–30 months. In all patients, we recorded the visual analog scale (VAS) score for waist pain and the Oswestry Disability Index (ODI) preoperatively, immediately postoperatively and at the last follow-up. We used the modified MacNab criteria to assess the curative effect at the last follow-up.

Results

All 20 patients underwent successful operations without complications. No recurrence was observed during follow-up. The VAS score of low back pain was 5.05±1.19 points before surgery, 1.50±051 points immediately after surgery, and 1.10±0.72 points at the last follow-up (P < 0.05 preoperative vs both postoperative). At the last follow-up, the VAS scores of all 20 patients were ≤2, and 4 patients had no pain. The ODI was 46.66±7.03% before surgery, 9.78±4.05% immediately after surgery, and 4.11±3.18% at the last (P < 0.05, preoperative vs both postoperative). According to the evaluation under the modified MacNab standard, the good–excellent rate of clinical efficacy at the last follow-up was 95%.

Conclusion

Percutaneous endoscopic spinal surgery can significantly improve the symptoms and dysfunction of young patients with DLBP and has little effect on the biomechanical stability of the lumbar spine. This surgery has great clinical application value.

Intervertebral disc therapies for non-specific chronic low back pain: a systematic review and meta-analysis

Objectives

We aim to evaluate the benefits and harms of intervertebral disc therapies (IDTs) in people with non-specific chronic low back pain (NScLBP).

Methods

We conducted a systematic review and meta-analysis of randomized trials of IDTs versus placebo interventions, active comparators or usual care. EMBASE, MEDLINE, CENTRAL and CINHAL databases and conference abstracts were searched from inception to June 2020. Two independent investigators extracted data. The primary outcome was LBP intensity at short term (1 week-3 months), intermediate term (3-6 months) and long term (after 6 months).

Results

Of 18 eligible trials (among 1396 citations), five assessed glucocorticoids (GCs) IDTs and were included in a quantitative synthesis; 13 assessed other products including etanercept (n = 2), tocilizumab (n = 1), methylene blue (n = 2), ozone (n = 2), chymopapaine (n = 1), glycerol (n = 1), stem cells (n = 1), platelet-rich plasma (n = 1) and recombinant human growth and differentiation factor-5 (n = 2), and were included in a narrative synthesis. Standardized mean differences (95% CI) for GC IDTs for LBP intensity and activity limitations were -1.33 (-2.34; -0.32) and -0.76 (-1.85; 0.34) at short term, -2.22 (-5.34; 0.90) and -1.60 (-3.51; 0.32) at intermediate term and -1.11 (-2.91; 0.70) and -0.63 (-1.68; 0.42) at long term, respectively. Odds ratios (95% CI) for serious and minor adverse events with GC IDTs were 1.09 (0.25; 4.65) and 0.97 (0.49; 1.91).

Conclusion

GC IDTs are associated with a reduction in LBP intensity at short term in people with NScLBP. Positive effects are not sustained. IDTs have no effect on activity limitations. Our conclusions are limited by high heterogeneity and a limited methodological quality across studies.

Registration

PROSPERO: CRD42019106336.

Methylene Blue Application to Lessen Pain: Its Analgesic Effect and Mechanism

Methylene blue (MB) is a cationic thiazine dye, widely used as a biological stain and chemical indicator. Growing evidence have revealed that MB functions to restore abnormal vasodilation and notably it is implicated even in pain relief. Physicians began to inject MB into degenerated disks to relieve pain in patients with chronic discogenic low back pain (CDLBP), and some of them achieved remarkable outcomes. For osteoarthritis and colitis, MB abates inflammation by suppressing nitric oxide production, and ultimately relieves pain. However, despite this clinical efficacy, MB has not attracted much public attention in terms of pain relief. Accordingly, this review focuses on how MB lessens pain, noting three major actions of this dye: anti-inflammation, sodium current reduction, and denervation. Moreover, we showed controversies over the efficacy of MB on CDLBP and raised also toxicity issues to look into the limitation of MB application. This analysis is the first attempt to illustrate its analgesic effects, which may offer a novel insight into MB as a pain-relief dye.

Intradiskal Injection of Methylene Blue for Discogenic Back Pain: A Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

 Intradiskal injection of methylene blue has some potential in alleviating discogenic back pain. This meta-analysis aims to explore the impact of intradiskal injection of methylene blue for discogenic back pain.

METHODS

 Several databases such as PubMed, EMbase, Web of Science, EBSCO, and Cochrane Library databases have been searched through November 2019, and randomized controlled trials (RCTs) assessing the effect of intradiskal injection of methylene blue for discogenic back pain are included.

RESULTS

 Three RCTs are included in the meta-analysis. Overall, compared with control group for discogenic back pain, intradiskal injection of methylene blue remarkably decreased pain scores at 3 months (mean difference [MD] = -0.71; 95% confidence interval [CI] = -0.96 to -0.46; p < 0.00001) and 6 months (MD = -13.92; 95% CI = -22.31 to -5.54; p = 001) and Oswestry Disability Index (ODI) at 4 to 6 weeks (MD = -10.39; 95% CI = -16.95 to -3.83; p = 0.002) and 3 months (MD = -3.66; 95% CI = -4.85 to -2.48; p < 0.00001), but demonstrated no obvious effect on ODI at 6 months (MD = -11.76; 95% CI = -33.33 to 9.80; p = 0.28).

CONCLUSIONS

 Intradiskal injection of methylene blue can substantially decrease pain scores and improve function for discogenic back pain.

Methylene blue induces an analgesic effect by significantly decreasing neural firing rates and improves pain behaviors in rats

Methylene blue (MB) is a blue cationic thiazine dye and currently used in different medical settings. Notably, there have been several attempts to introduce MB for attenuating pain in the last decade. Some clinical studies reported remarkable results, which, however, have been much debated. In addition, accumulating evidence have revealed that MB diminishes voltage-gated sodium channel currents. Accordingly, in the present study, we conducted in vivo experiments, including in vivo single nerve recording and behavioral test, to investigate whether MB dampens neural firing rates and ultimately contributes to pain relief. As a result, neural firing rates significantly decreased and finally converged to zero after MB administration. This event lasted longer than that of lidocaine and was dose-dependently modulated. Furthermore, there was a marked improvement in pain behaviors. The withdrawal threshold and latency of hind paws significantly rose post-MB administration. Therefore, these results demonstrate that MB lessens pain by significantly weakening neural excitability, which implies a strong possibility that this dye may be developed as a pain-relieving medication in the future. This is the first in vivo study to elucidate the effect of MB on nerves and pain relief.

Could methylene blue be used to manage burning mouth syndrome? A pilot case series

Objective: Burning mouth syndrome is a disabling condition of complex pathophysiology characterized by spontaneous pain felt in the oral mucosa in the absence of evident mucosal lesions which lacks efficient treatments to this day. The purpose of this study was to demonstrate the efficacy of methylene blue in the management of burning mouth syndrome. Methods: The study was conducted at the dental clinic of the Anta Diop University and Newtown dental clinic of Dakar, Senegal. A solution of methylene blue as a mouth-rinse (0.5%) was applied for 5 minutes in five patients satisfying the ICHD-3 diagnostic criteria for burning mouth syndrome. This procedure was repeated every 6 hours 3 times per 24h, during 7 days. Using numeric rating scale, pain severity was assessed as the mean pain felt during the last day of application. Results: After 7 days, the pain was significantly reduced by two-thirds and almost absent at 3 and 6 months follow-up. No secondary effects of the use of methylene blue were observed. Putative mechanisms of action and potential implications for treatment are discussed. Conclusion: Methylene blue is an old compound but a novel topical therapy that could prove beneficial in the management of burning mouth syndrome.

The Chinese Association for the Study of Pain (CASP): Consensus on the Assessment and Management of Chronic Nonspecific Low Back Pain

Chronic nonspecific low back pain (CNLBP) is defined as pain or discomfort originating from the waist, which lasts for at least 12 weeks, but no radiculopathy or specific spinal diseases. CNLBP is a complicated medical problem and places a huge burden on healthcare systems. Clinical manifestation of CNLBP includes discogenic LBP, zygapophyseal joint pain, sacroiliac joint pain, and lumbar muscle strain. Further evaluation should be completed to confirm the diagnosis including auxiliary examination, functional assessment, and clinical assessment. The principle of the management is to relieve pain, restore function, and avoid recurrence. Treatment includes conservative treatment, minimally invasive treatment, and rehabilitation. Pharmacologic therapy is the first-line treatment of nonspecific LBP, and it is most widely used in clinical practice. Interventional therapy should be considered only after failure of medication and physical therapy. Multidisciplinary rehabilitation can improve physical function and alleviate short-term and long-term pain. The emphasis should be put on the prevention of NLBP and reducing relevant risk factors.

Effectiveness of Methylene Blue in the Prevention of Stifle Joint Arthrofibrosis in Rabbit Models

BACKGROUND

One of the major challenges in orthopedic surgery is the prevention of arthrofibrosis, which can be successfully alleviated in its early stages. Many studies suggest the administration of methylene blue (MB) as an accessible and effective agent for the prevention of post-operation adhesions. The purpose of this study was to evaluate the efficacy of MB in the prevention of arthrofibrosis.

METHODS

This study was conducted on 18 New Zealand white female mature rabbits. The anterior cruciate ligament of the left stifle joint of each animal was cut during aseptic surgery. In the next step, the rabbits were divided into three groups based on their treatments. The rabbits in the first, second, and third groups were subjected to the injection of normal saline, 1% MB solution, and 2% MB solution into their synovial space, respectively. The postoperative stifle range of motion was measured every week. After 4 weeks, the animals were euthanized and all joints were dissected for histopathology.

RESULTS

The histopathological evaluation of tissues indicated the presence of fibrotic connective tissue as a sign of fibrosis in all groups. The fibrosis rate, inflammatory rate, tissue disarrangement, fibroblastic cellularity, and granulation tissue formation were at their highest levels in the 1% MB group. The integrity of articular cartilage in the 2% MB group was lower than the other groups. The level of bone degeneration was similar in both MB groups; however, it was more than the control saline group. The range of motion was reduced during the first week, then increased in the second and third weeks, and finally decreased in the fourth week.

CONCLUSION

The MB was not an effective method regarding the prevention or treatment of arthofibrosis and the subsequent osteoarthritis. In contrast with previous studies, fibrosis was lower in the high dose MB group, compared to the low dose MB group. The alterations in the range of motion were related to the reduced movement caused by the pain and stiffness of the operated joints. The current study can be considered as the first report addressing the adverse effect of MB on synovial components.

LEVEL OF EVIDENCE

I.

Discogenic low back pain: interventional treatment

Low back pain (LBP) is one of the most common causes of disability in the adult population. A significant place in its genesis is occupied by a degenerative-dystrophic diseases of intervertebral discs. The article highlights the classification and mechanism of discogenic pain origin. Various types of interventions aredescribed for this pathology: indications, specificities of carrying out manipulations and therapeutic effects, efficiency and possible complications of procedures.

[Platelet-rich plasma (PRP) and disc lesions: A review of the literature]

The spine has been the subject of extensive clinical research since it is the source of many painful complaints. However, there is little scientific evidence concerning the therapeutic proposals. During the course of life, the intervertebral disc degenerates, which over time diminishes its damping capacity and facilitates the expulsion of the nucleus pulposus through the annulus fibrosus. The degeneration of the intervertebral disc (DDI) is the origin of some back pain and various specific treatments have been developed. These include the infiltration at the center of the intervertebral disc of plasma rich platelet (PRP), composed of multiple growth factors which act on the disc degeneration. This treatment is recent and less invasive than surgery. Preliminary results seem promising. However, many gray areas and several parameters remained to be clarified. In an attempt to do this, a literature review was conducted based on bibliographic databases Pubmed, Medline and Scopus^® using the following Mesh terms : PRP, platelet-rich plasma, intradiscal disc degeneration, disc, intradiscal, discogenic. This analysis reveals that at the present time, no reported study has a sufficient perspective to judge the effectiveness of the infiltration of PRP. Early harvest results will be used to set the limits of this treatment. Accordingly, it is therefore currently recommended to introduce PRP injection as a complementary solution to comprehensive care of the spine. Future research will need to generate randomized controlled studies including comparing the results with conservative treatment and measure the cost-benefit relationship.

Clinical Significance of High-intensity Zone for Discogenic Low Back Pain: A Review

High-intensity zone (HIZ) was originally described as a high-intensity signal on T2-weighted magnetic resonance (MR) images, located in the posterior annulus fibrosus, clearly separated from the nucleus pulposus. Among symptomatic patients with low back pain, HIZ is present in 28-59% of cases. In morphologically abnormal discs, high sensitivity and specificity of 81% and 79%, respectively, were reported for HIZs and concordant pain during discography. In contrast, another report indicated low rates. Although most papers reported high sensitivity and specificity for this relationship, it remains controversial. Regarding the pathology of HIZs, inflammatory granulation tissues are found at sites showing HIZs. Such inflammatory tissues produce pro-inflammatory cytokines and mediators, which sensitize the nociceptors within the disc and cause pain. An effective treatment for this condition is yet to be established. Recently, minimally invasive surgery using percutaneous endoscopic discectomy (PED) under local anesthesia was introduced. After removal of the degenerated disc material, the HIZ is identified with the endoscope and then coagulated and modulated with a bipolar radio pulse. This technique is called thermal annuloplasty. In conclusion, HIZs is an important sign of painful intervertebral disc disruption, if identified precisely based on factors such as location and intensity.

Effects of methylene blue on postoperative low-back pain and functional outcomes after lumbar open discectomy: a triple-blind, randomized placebo-controlled trial

OBJECT

Despite advances in surgical and anesthesiology techniques, many patients continue to experience postoperative pain after lumbar disc operations. This study aims to investigate the effects of methylene blue (MB) on preventing postoperative low-back pain (LBP) with or without radicular pain and improving the quality of life (QOL) in patients undergoing lumbar open discectomy.

METHODS

This is a prospective, randomized, triple-blind, placebo-controlled clinical trial, which was conducted at Shiraz University of Medical Sciences between July 2011 to January 2012. Of a total of 130 patients, 115 were eligible for participation; 56 received 1 ml of MB solution at a concentration of 0.5% (MB group) and 59 received an equivalent volume of normal saline (control group). Primary outcomes were the control of LBP with or without radicular pain, which was evaluated preoperatively and at 24 hours and 3 months after surgery with the use of a visual analog scale (VAS), and the improvement of QOL, which was assessed preoperatively and 3 months postoperatively by means of the Persian translation of the Oswestry Disability Index questionnaire.

RESULTS

The mean VAS scores for LBP were significantly lower in the MB group compared with the control group at 24 hours (1.25 ± 0.97 vs 2.80 ± 0.69, p < 0.001) and 3 months (1.02 ± 1.29 vs 2.07 ± 1.10, p = 0.019) after treatment. The mean radicular pain scores decreased significantly in the 2 groups at 24 hours after surgery, but the mean radicular pain score was significantly lower in the MB-treated patients than the control group. However, the difference between radicular pain scores in the MB group (1 ± 1.1) and the control group (1.2 ± 1) was not statistically significant (p = 0.64). The reduction in LBP was greater in the MB group than the control group (8.11 ± 1.74 vs 6.07 ± 1.52, p = 0.023, CI 95% −1.37 to −0.10). The functional QOL improved significantly 3 months after the operation in both groups (p < 0.001). Moderate disability occurred more frequently in the control group than in the MB group (14.5% vs 7.7%, p = 0.004). No toxicity, adverse effects, or complications were found in the group of patients treated with MB injection.

CONCLUSIONS

A single dose of MB (1 ml 0.5%) for coating the dura and surrounding tissues (facet and muscle) shows promising results in terms of safety, reduction of postoperative pain, and functional outcome compared with placebo.

Efficacy, Safety, and Predictors of Intradiscal Methylene Blue Injection for Discogenic Low Back Pain: Results of a Multicenter Prospective Clinical Series

STUDY DESIGN

Prospective clinical study of intradiscal methylene blue injection for the treatment of lumbar discogenic pain.

OBJECTIVE

The objective of this study was to collect information about efficacy, safety, and acceptability of the intervention, gain and burden of outcome measures, and sample size assumptions for a potential following randomized controlled trial (RCT). If the pilot study demonstrates that this treatment is potentially effective and safe, and the methods and procedures used in this study are feasible, a RCT follows.

SUMMARY OF BACKGROUND DATA

Low back pain (LBP) is a highly common problem with a lifetime prevalence of more than 70%. A substantial part of chronic LBP is attributable to degenerative changes in the intervertebral disc. A recently published RCT assessing the treatment intradiscal injection of methylene blue for chronic discogenic LBP, showed exceptionally good results.

METHODS

Patients were selected on clinical criteria, magnetic resonance imaging, and a positive provocative discogram. The primary outcome measure was mean pain reduction at 6 months.

RESULTS

Fifteen consecutive patients with chronic lumbar discogenic pain enrolled in a multicenter prospective case series in two interventional pain treatment centers in the Netherlands. Six months after the intervention, 40% of the patients claimed at least 30% pain relief. In patients who responded, physical function improved and medication use diminished. We observed no procedural complications or adverse events. Predictors for success were Pfirrmann grading of 2 or less and higher quality of life mental component scores.

CONCLUSIONS

Our findings of 40% positive respondents, and no complications, give reason to set up a randomized, double-blind, placebo-controlled, trial.

Posterolateral transforaminal selective endoscopic diskectomy with thermal annuloplasty for discogenic low back pain: a prospective observational study

STUDY DESIGN

A prospective observational study on 113 patients with 3 years of follow-up.

OBJECTIVE

To evaluate the clinical results of therapy for discogenic low back pain (DLBP) with posterolateral transforaminal selective endoscopic diskectomy and thermal annuloplasty (PEDTA).

SUMMARY OF BACKGROUND DATA

Currently, various minimally invasive techniques are widely used to treat chronic DLBP with variable clinical outcomes. PEDTA is considered to be a novel, minimally invasive technique for treating chronic DLBP, but the evidence supporting this technique is very limited, and there are no studies demonstrating at least 3 years of follow-up.

METHODS

One hundred thirteen consecutive patients with DLBP with positive concordant pain in discography underwent PEDTA from March 2008 to March 2010. These patients included 64 males and 49 females with a mean age of 43.7 years (range, 16-75 yr). The visual analogue scale score, Japanese Orthopedic Association score, and Oswestry Disability Index were evaluated before therapy and each year after surgery. The clinical global outcomes were assessed on the basis of modified MacNab criteria at 3 years after surgery.

RESULTS

Ninety-six patients underwent a single-level procedure, and 17 patients underwent multilevel procedures. One hundred one (89.4%) cases were followed up for 3 years. There were no serious complications observed during follow-up. The success rate (excellent and good) was 73.8%. The visual analogue scale score, Japanese Orthopedic Association score and Oswestry Disability Index had significantly improved at each year after surgery (P < 0.01, compared with presurgery). The success rate in patients who underwent a single-level procedure was remarkably higher than that in patients who underwent multilevel procedures (78.2% vs. 50.0%, P = 0.041).

CONCLUSION

PEDTA presents a safe and effective treatment for carefully selected groups of patients with DLBP. Better clinical results occurred in patients with single-level discogenic pain.

The prevention effect of poly (L-glutamic acid)/chitosan on spinal epidural fibrosis and peridural adhesion in the post-laminectomy rabbit model

PURPOSE

Spinal epidural fibrosis and adhesion are implicated as one of the key factors of failed back surgery syndrome, which may cause dura mater compression or peridural tethering, resulting in persistent backache and leg pain. Various materials or drugs have been used to inhibit formation of epidural fibrosis and reduce the compressive effect on neural structures. Nevertheless, the effects are not satisfied. In this study, we investigated the prevention effect of poly (L-glutamic acid)/chitosan (PLGA/CS) barrier on epidural fibrosis developing post-laminectomy in a rabbit model.

METHODS

Sixteen rabbits were divided randomly into two equal groups: group A (experimental group, n = 8) and group B (non-treatment group, n = 8). In both groups, total L5-6 laminectomy was performed; further both ligamentum flavum and epidural fat were removed gently. In experimental group, the laminectomy sites were treated with PLGA/CS barriers, while no additional treatment was received in non-treatment group. At 1, 12 and 24 weeks post-surgery, the animals were subjected to magnetic resonance imaging (MRI) evaluation. Following last MRI examination, all rabbits were sacrificed and their spinal columns were totally removed for further macroscopic and histological evaluation.

RESULTS

MRI showed that rabbits treated with PLGA/CS barrier at 12 and 24 weeks post-surgery had less epidural fibrosis or scar tissue, peridural adhesion, foreign body reaction and low pressure of spinal cord in comparison with the non-treatment group. In consistence with the radiographic results, macroscopic analysis and histological examination showed that the amount of scar tissue and the extent of epidural adhesion decreased significantly in experimental groups. Concerning the fibroblast density evaluated, the scores were significantly lower in experimental group compared with those in non-treatment group.

CONCLUSION

The results of our study demonstrate that PLGA/CS barrier is effective in inhibiting epidural fibrosis and peridural adhesions in post-laminectomy rabbit model.

Diagnostic criteria and treatment of discogenic pain: a systematic review of recent clinical literature

BACKGROUND CONTEXT

Pain innate to intervertebral disc, often referred to as discogenic pain, is suspected by some authors to be the major source of chronic low back and neck pain. Current management of suspected discogenic pain lacks standardized diagnosis, treatment, and terminology.

PURPOSE

In an attempt to determine whether patterns existed that may facilitate standardization of care, we sought to analyze the terminologies used and the various modes of diagnosis and treatment of suspected discogenic pain.

STUDY DESIGN

A systematic review of the recent literature.

METHODS

A Medline search was performed using the terms degenerative disc disease, discogenic pain, internal disc disruption while using the limits of human studies, English language, and clinical trials, for the last 10 years. The search led to a total of 149 distinct citations, of which 53 articles, where the intervertebral disc itself was considered the principal source of patient's pain and was the main target of the treatment, were retained for further analysis.

RESULTS

The results of this review confirm and help quantify the significant differences that existed in the terminology and all the areas of diagnosis and treatment of presumed discogenic pain.

CONCLUSIONS

Our findings show that suspected discogenic pain, despite its extensive affirmation in the literature and enormous resources regularly devoted to it, currently lacks clear diagnostic criteria and uniform treatment or terminology.

Mechanisms of intervertebral disk degeneration/injury and pain: a review

Degeneration of the intervertebral disk and its treatments are currently intensely investigated topics. Back pain is a condition whose chronic and debilitating nature combined with its prevalence make it a major health issue of substantial socioeconomic importance. Although researchers, and even sometimes clinicians, focus on the degenerated disk as the problem, to most patients, pain is the factor that limits their function and impacts their well-being. The purpose of this review is to delineate the changes associated with disk degeneration and to outline mechanisms by which they could be the source of back pain. Although the healthy disk is only innervated in the external layer of its annulus fibrosus, adjacent structures are plentiful with nociceptive receptors. Stimulation of such structures as a consequence of processes initiated by disk degeneration is explored. The concept of discogenic pain and possible mechanisms such as neoinnervation and solute transport are discussed. Finally, how such pain mechanisms may relate to current and proposed treatment strategies is discussed.

Pathophysiology, diagnosis, and treatment of discogenic low back pain

Discogenic low back pain is a serious medical and social problem, and accounts for 26%-42% of the patients with chronic low back pain. Recent studies found that the pathologic features of discs obtained from the patients with discogenic low back pain were the formation of the zones of vascularized granulation tissue, with extensive innervation in fissures extending from the outer part of the annulus into the nucleus pulposus. Studies suggested that the degeneration of the painful disc might originate from the injury and subsequent repair of annulus fibrosus. Growth factors such as basic fibroblast growth factor, transforming growth factor β1, and connective tissue growth factor, macrophages and mast cells might play a key role in the repair of the injured annulus fibrosus and subsequent disc degeneration. Although there exist controversies about the role of discography as a diagnostic test, provocation discography still is the only available means by which to identify a painful disc. A recent study has classified discogenic low back pain into two types that were annular disruption-induced low back pain and internal endplate disruption-induced low back pain, which have been fully supported by clinical and theoretical bases. Current treatment options for discogenic back pain range from medicinal anti-inflammation strategy to invasive procedures including spine fusion and recently spinal arthroplasty. However, these treatments are limited to relieving symptoms, with no attempt to restore the disc's structure. Recently, there has been a growing interest in developing strategies that aim to repair or regenerate the degenerated disc biologically.

Effect of Intradiscal Methylene Blue Injection for the Chronic Discogenic Low Back Pain: One Year Prospective Follow-up Study

Objective

To evaluate the efficacy of intradiscal methylene blue (MB) injection in patients with chronic discogenic low back pain.

Method

Twenty patients with discogenic low back pain (4 males, 16 females; mean age 45.6 years) refractory to conservative management were recruited. All subjects underwent MB injection in target lumbar intervertebral discs confirmed by provocative discography. The clinical outcome was assessed by visual analog scale (VAS) and Oswestry disability index (ODI) at baseline and 1, 3, 6 and 12 months after treatment. Successful outcome was described as minimum of 2 points reduction in pain intensity compared with the baseline.

Results

VAS and ODI significantly decreased after one injection. The average VAS and ODI were reduced significantly from 5.1 and 38.0 at baseline to 3.2 and 27.4 at 3 months after injection (p<0.05). However, the mean score of VAS at 12 month follow-up was 4.5 and we could not observe any difference between 12 months after injection and pretreatment. Eleven of twenty patients (55%) reported successful outcomes after intradiscal MB injection at 3 month follow up and the average VAS was reduced by 3.3±1.1 (p<0.05). At the time of 12 month follow up, pain had relapsed in 6 patients who have had satisfactory effect at 3 month follow up. Successful outcome was maintained in only 5 patients (20%) for 1 year.

Conclusion

The intradiscal MB injection is a short-term effective minimally invasive treatment indicated for discogenic back pain but it may lose its effectiveness long-term.

The young adult spine in sports

In summary, LBP is a common problem for the young adult athlete, with discogenic pain being the most common of all etiologies. Although rare, more serious etiologies such as tumor or infection should be included in the differential diagnosis until effectively ruled out. Regardless of the cause, nonoperative and conservative strategies should be the cornerstone of treatment, owing to the favorable natural history of most LBP etiologies. Short-term non-narcotic medications are helpful, and avoidance of bed rest is critical for the athletic population. Rehabilitation should focus on stabilization and strengthening of the core and pelvic muscle groups, and biomechanical imbalances should be addressed. Surgical intervention ought to be utilized as a last resort in this population. Return to play should be considered only when the athlete is pain free with full range of motion and daily medications have been discontinued. Careful monitoring of the training regimen should always be undertaken,especially with chronic pain or recurrent injuries.

Cellular and molecular actions of Methylene Blue in the nervous system

Methylene Blue (MB), following its introduction to biology in the 19th century by Ehrlich, has found uses in various areas of medicine and biology. At present, MB is the first line of treatment in methemoglobinemias, is used frequently in the treatment of ifosfamide-induced encephalopathy, and is routinely employed as a diagnostic tool in surgical procedures. Furthermore, recent studies suggest that MB has beneficial effects in Alzheimer's disease and memory improvement. Although the modulation of the cGMP pathway is considered the most significant effect of MB, mediating its pharmacological actions, recent studies indicate that it has multiple cellular and molecular targets. In the majority of cases, biological effects and clinical applications of MB are dictated by its unique physicochemical properties including its planar structure, redox chemistry, ionic charges, and light spectrum characteristics. In this review article, these physicochemical features and the actions of MB on multiple cellular and molecular targets are discussed with regard to their relevance to the nervous system.

Intradiscal injection therapy for degenerative chronic discogenic low back pain with end plate Modic changes

BACKGROUND CONTEXT

The effect of intradiscal steroid therapy for patients with degenerative chronic discogenic low back pain remains an issue of debate.

PURPOSE

To evaluate the effect of various intradiscal injection regimens for patients with degenerative chronic discogenic low back pain and end plate Modic changes.

STUDY DESIGN

Double-blind, randomized, controlled, prospective clinical study.

PATIENT SAMPLE

One hundred twenty patients with discogenic low back pain and end plate Modic changes on magnetic resonance imaging (MRI) who received discography but were unwilling to accept surgical operation.

OUTCOME MEASURES

Pain and function were determined by the visual analog scale (VAS) and the Oswestry Disability Index (ODI) assessment.

METHODS

Patients who received diagnostic discography for suspected degenerative discogenic low back pain were recruited. A total of 120 patients with positive discography and end plate Modic changes at a single level were enrolled in the study and allocated into Groups A and B according to the type of Modic changes on MRI. Then, the patients in Groups A and B were randomized into three subgroups, respectively. Intradiscal injection of normal saline was performed in Subgroups A1 and B1, intradiscal injection of diprospan was performed in Subgroups A2 and B2, and intradiscal injection of a mixed solution of diprospan+songmeile (cervus and cucumis polypeptide) was performed in Subgroups A3 and B3. The clinical outcome of each patient was evaluated and recorded by using the VAS and ODI at 3 and 6 months after the procedure.

RESULTS

The subgroups were comparable with respect to gender, age, pain, and percentage disability. Neither VAS pain scores nor Oswestry function scores of the patients within Group A had any improvement at 3 or 6 months after saline injection, but both of them improved significantly at the two time points after diprospan and diprospan+songmeile injection, respectively. Meanwhile, the latter two injection protocols led to no significant difference in pain relief and functional recovery. Similar results were obtained in patients within Group B. Furthermore, no difference of the improvement of VAS pain scores or Oswestry function scores was found between the patients within Group A and within Group B at different time points after various interventions.

CONCLUSION

Intradiscal injection of corticosteroids could be a short-term efficient alternative for discogenic low back pain patients with end plate Modic changes on MRI who were still unwilling to accept surgical operation when conservative treatment failed.

The effect of methylene blue on peridural fibrosis formation after laminectomy in rats: an experimental novel study

BACKGROUND CONTEXT

Despite progress in surgical techniques, some patients still face postoperative recurrence of pain, although the rate of successful outcomes is estimated to be approximately 70% and 86% after primary decompression spinal surgery. Recently, attention has been focused on peridural fibrosis (PF), which may be responsible for recurrent pain after laminectomy or discectomy. Methylene blue (MB) has been shown to prevent fibrosis formation in various tissues.

PURPOSE

The aims of this study were to investigate the effects of MB and assess the effects of different doses on the prevention of postlaminectomy fibrosis formation in a rat model. This preclinical model is a potential platform for future clinical trials to identify an effective agent for the prevention of clinically important epidural scar formation.

STUDY DESIGN

An established bilateral L5-L6 rat laminectomy model was used to evaluate postlaminectomy PF with macroscopic and microscopic analyses.

PATIENT SAMPLE

Seventy-five male adult white Sprague-Dawley rats that underwent laminectomy at the L5-L6 levels were divided into five groups of 15 rats each.

OUTCOME MEASURES

Dissected specimens were evaluated macroscopically and microscopically by examiners who were unaware of the group assignment to record the presence or absence of PF formation.

METHODS

Groups A and B served as controls and Groups C, D, and E received treatment. Group A (sham) underwent laminectomy, and Group B was treated with normal saline at the laminectomy site. Rats in Groups C, D, and E received 0.1 mL MB at concentrations of 0.5%, 1%, and 2%, respectively, at the laminectomy site. All rats were killed 4 weeks after laminectomy. The results were compared statistically with the nonparametric Kruskal-Wallis test and Poisson regression.

RESULTS

Peridural fibrosis was found in five rats (33%) in control Groups A and B and in two rats (10%) in MB-treated laminectomy Groups C and D. The difference between control and MB groups was not statistically significant (p = .27). The preventive effect of MB on PF was not seen at the highest dose of MB (2%) in Group E. Severity of fibrosis was lower in Groups C (MB 0.5%) and D (MB 1%) than in Group E (MB 2%) (p < .01). Wound healing was not affected, and there was no cerebrospinal fluid leakage. No neurological deficits were seen.

CONCLUSION

Low doses of MB may be an effective agent in preventing PF formation after lumbar laminectomy in rats. Clinical significance and safety in human use are currently undetermined.

Effect of honey on peridural fibrosis formation after laminectomy in rats: a novel experimental study

Despite progress in surgical techniques, some patients still face postoperative recurrence of pain. Recently, more attention has been focused on peridural fibrosis (PF), which may be responsible for recurrent pain after laminectomy or discectomy. Honey has been shown to exert anti-inflammatory effects on exposed tissues besides its well-known antibacterial properties. The aim of this study were to investigate the effects of honey on the prevention of postlaminectomy fibrosis formation in a rat model. A controlled blinded study was performed in 45 male adult white Sprague-Dawley rats that underwent laminectomy at the L5-L6 levels. They were divided into 3 groups (A, B, and C) of 15 rats each. Group A (sham) underwent laminectomy and group B was treated with normal saline at the laminectomy site. Rats in group C received 0.1 mL honey at the laminectomy site. All rats were killed 4 weeks after laminectomy. PF was found in 5 rats (33%) of control groups A and B, and in 2 rats (10%) in honey-treated laminectomy group C. The difference was not statistically significant. Wound healing was not affected, and there was no cerebrospinal fluid leakage. Although honey appears to be safe, it cannot cause a significant reduction of PF formation after lumbar laminectomy in rats.

New challenges for intervertebral disc treatment using regenerative medicine

The development of tissue engineering therapies for the intervertebral disc is challenging due to ambiguities of disease and pain mechanisms in patients, and lack of consensus on preclinical models for safety and efficacy testing. Although the issues associated with model selection for studying orthopedic diseases or treatments have been discussed often, the multifaceted challenges associated with developing intervertebral disc tissue engineering therapies require special discussion. This review covers topics relevant to the clinical translation of tissue-engineered technologies: (1) the unmet clinical need, (2) appropriate models for safety and efficacy testing, (3) the need for standardized model systems, and (4) the translational pathways leading to a clinical trial. For preclinical evaluation of new therapies, we recommend establishing biologic plausibility of efficacy and safety using models of increasing complexity, starting with cell culture, small animals (rats and rabbits), and then large animals (goat and minipig) that more closely mimic nutritional, biomechanical, and surgical realities of human application. The use of standardized and reproducible experimental procedures and outcome measures is critical for judging relative efficacy. Finally, success will hinge on carefully designed clinical trials with well-defined patient selection criteria, gold-standard controls, and objective outcome metrics to assess performance in the early postoperative period.

A randomized placebo-controlled trial of intradiscal methylene blue injection for the treatment of chronic discogenic low back pain

A preliminary report of clinical study revealed that chronic discogenic low back pain could be treated by intradiscal methylene blue (MB) injection. We investigated the effect of intradiscal MB injection for the treatment of chronic discogenic low back pain in a randomized placebo-controlled trial. We recruited 136 patients who were found potentially eligible after clinical examination and 72 became eligible after discography. All the patients had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-six were allocated to intradiscal MB injection and 36 to placebo treatment. The principal criteria to judge the effectiveness included alleviation of pain, assessed by a 101-point numerical rating scale (NRS-101), and improvement in disability, as assessed with the Oswestry Disability Index (ODI) for functional recovery. At the 24-month follow-up, both the groups differed substantially with respect to the primary outcomes. The patients in MB injection group showed a mean reduction in pain measured by NRS of 52.50, a mean reduction in Oswestry disability scores of 35.58, and satisfaction rates of 91.6%, compared with 0.70%, 1.68%, and 14.3%, respectively, in placebo treatment group (p<0.001, p<0.001, and p<0.001, respectively). No adverse effects or complications were found in the group of patients treated with intradiscal MB injection. The current clinical trial indicates that the injection of methylene blue into the painful disc is a safe, effective and minimally invasive method for the treatment of intractable and incapacitating discogenic low back pain.

Nitric oxide and pain: 'Something old, something new'

Challenges have emerged following the revival of nitric oxide (NO) from 'something old', a simple gas derived from nitrogen and oxygen with a role in the early stages of evolution, into 'something new', an endogenously formed biological mediator regulating a wide variety of physiological functions. Although pain is a common sensation, it encompasses multiple neurobiologic components, of which NO is only one. In pain research, the study of NO is complicated by convoluted problems related mostly to the effects of NO, which are pro- or anti-nociceptive depending on the circumstances. This dual function reflects the multi-faceted roles of the NO molecule described in physiology. This review covers current information about NO and its implications in pain mechanisms. In addition, it follows the pain pathways, demonstrating the role of NO in peripheral nociceptive transmission as well in central sensitization. This knowledge may provide the scientific basis for developing new drugs that are indicated for different types of pain, drugs that may be related to the chemical links of NO. A comprehensive approach to understanding the effects of NO will help clinicians identify novel agents that combine the pharmacological profile of native drugs with a controllable manner of NO release. Inhibitors of NO synthesis may have analgesic effects and would be of interest for treating inflammatory and neuropathic pain. Unfortunately, only a few of these compounds have reached the stage of clinical pain trials.