15. Discogenic Low Back Pain

Evaluation and Treatment of Low Back Pain: A Clinically Focused Review for Primary Care Specialists

Low back pain (LBP) is a leading cause of disability worldwide. In the absence of a classification system for pain syndromes, classification of LBP on the basis of the distribution of pain as axial (pain generally localized to the low back) or radicular neuropathic (pain radiating to the lower extremities) is relevant to clinical practice because the distribution of pain is often a corollary of frequently occurring disease processes involving the lumbar spine. Common sources of axial LBP include the intervertebral disc, facet joint, sacroiliac joint, and paraspinal musculature, whereas common sources of radicular pain include a herniated intervertebral disc and spinal stenosis. The accuracy of historical and physical examination findings has been established for sacroiliac joint pain, radiculopathy, and lumbar spinal stenosis. However, the accuracy of similar data, so-called red flags, for identifying the underlying medical sources of LBP has been overstated. Diagnostic imaging studies can be useful, and adherence to established guidelines can protect against overuse. Multiple pharmacological trials exist for the management of LBP; however, the long-term outcomes of commonly used drugs are mixed. For carefully selected patients with axial LBP, radiofrequency denervation techniques can provide sustained pain relief. In patients with radicular pain, transforaminal epidural steroid injections may provide short-term pain relief, but neurostimulation may confer more enduring benefits of refractory symptoms. Pain-related indications for commonly performed operations include spinal decompression for radicular symptoms as well as spinal fusion or disc prosthesis for discogenic LBP. Physical modalities and psychological treatments can improve pain and functioning, but patient preferences may influence treatment adherence.

Efficacy and cost-effectiveness of intradiscal methylene blue injection for chronic discogenic low back pain: study protocol for a randomized controlled trial

BACKGROUND

Low back pain (LBP) is a common health problem and a substantial part of LBP is presumed to be attributable to degeneration of the intervertebral disc. For patients suffering from intractable discogenic LBP, there are few evidence-based effective interventional treatment options available. In 2010, the results of a randomized controlled trial (RCT) were published concerning "intradiscal methylene blue injection" (IMBI), in which this intervention appeared to be very successful in relieving discogenic pain. Therefore, we decided to repeat this study to investigate whether we could replicate the published results. The results of our preliminary feasibility study gave reason to set up an RCT. The aim of this RCT is to evaluate if IMBI is a more effective treatment of discogenic low back pain as an intradiscal placebo intervention, and furthermore, to assess the cost-effectiveness of this intervention.

METHODS/DESIGN

Consecutive discogenic low back pain patients referred to four specialized pain treatment facilities are being screened for eligibility. After a positive standardized provocation discography and informed consent, patients are randomized into two groups. The treatment group receives an intradiscal injection with methylene blue, lidocaine, and contrast, and the control group receives intradiscal isotonic saline with lidocaine and contrast. Main outcome measures are pain at the 6-month follow-up, patient's global impression of change, cost-effectiveness, quality of life, disability, and analgesic intake.

DISCUSSION

The importance of this study is emphasized by the fact that for intractable discogenic low back pain patients, evidence-based effective pain treatments are rare. If this study establishes clinical success and cost-effectiveness, IMBI could become the "pain treatment of choice" for a selected group of patients with chronic discogenic low back pain for whom noninvasive treatment options have failed.

TRIAL REGISTRATION

National Trial register NTR2547 Registered at 29 September 2010 and 31 March 2014.

The differential diagnosis of low back pain: a primer on the evolving paradigm

OBJECTIVES

The issue of low back pain (LBP) is as common as it is perplexing. LBP is thought to be a chronic issue in approximately 10% of the U.S. population. This condition has wide-reaching social and economical reverberations. Despite the availability of modern diagnostic tools, the cause of the pain generator is often unidentifiable. The authors were asked to create an overview of the etiology of LBP for physicians who implant neurostimulation devices for the treatment of chronic pain patients. Some prevalence data, based on the current available literature, have been provided for the more common structural conditions causing LBP. However, a comprehensive review of prevalence of various conditions and their respective manifestations as LBP is beyond the scope of this article.

MATERIALS AND METHODS

A review was performed of frequently cited articles with search terms for "low back pain" using PubMed, Medline, and Google Scholar. The authors also reviewed other literature from commonly utilized sources in the field of interventional pain medicine such as the journals of Neuromodulation, Pain Medicine, Spine, and Neurosurgery in the publication date range of 1975 to the present. Moreover, recent edition textbooks of other specialties such as obstetrics and gynecology, neurology, internal medicine, and surgery were referenced to develop a comprehensive list of the differential diagnoses. In order to capture the broad scope of information presented in this article, the criteria used to choose the references included published peer-reviewed articles that provided information on LBP as a symptom of a case report to common presentations of various conditions as described in a number of current, and commonly used, textbooks in their specialty.

RESULTS

The article serves as a reference for commonly cited causes of LBP as well as less common conditions presenting with LBP as a possible symptom, which may occur as a solitary pain generator or in combination with other etiologies. The information is structured in such a fashion to allow a comprehensive overview for every reader, including the most experienced implanting physicians. The article is designed to kindle critical thinking regarding the massive scope involved in the assessment of a patient with a complaint of LBP. The results of the comprehensive research to produce this article clearly indicate the broad scope of this list of differential diagnoses. The reader should be aware that the lists are by no means all-inclusive. Perhaps additional efforts will be necessary to build on the available information in this article in the future. Furthermore, although some prevalence data for LBP, as it is related to structural spine, is readily available based on the excellent work of our colleagues and presented throughout this paper, for other disease processes, the prevalence data are scarce to nonexistent. This underscores the need for further research to better understand this elusive condition. The size and breadth of the topic at hand in this article would arguably deserve its own comprehensive textbook. The complexity and discussion points of each identified pain generator could be given a chapter or section to reflect complex learning deserved by each topic. With these limitations, the authors recommend the reader to evaluate this article in the context of a broader topic of LBP and neurostimulation.

CONCLUSIONS

LBP is an extremely common condition associated, as a symptom, with various disease processes, regardless of their relationship with the lumbar spine or its innervation. This article underscores the broad nature of LBP as a symptom of many diagnoses. The primary conclusion reached by the authors is the most important recommendation by all mentors in medicine, which is to obtain a comprehensive history and perform a complete physical examination on each patient. Despite the fact that there is an emerging school of thought questioning the validity of the physical examination, this tool continues to be the current standard of care and used by a majority of clinicians around the world. The physician must analyze the information obtained from his/her history, physical examination, and diagnostic tools with the recognition of the broad nature of the differential diagnoses of LBP in order to be able to best treat the patient.

Efficacy of coblation technology in treating cervical discogenic upper back pain

Upper back pain originating from the cervical disk itself is defined as cervical discogenic upper back pain. Coblation procedures can provide therapeutic effects for neck and radicular pain related to contained cervical disk herniation. However, no studies have reported the performance of coblation procedures, particularly for treating cervical discogenic upper back pain. The purpose of this study was to evaluate the efficacy of coblation procedures in treating cervical discogenic upper back pain.In a prospective, clinical, observational study, 28 consecutive patients with discogenic upper back pain underwent coblation procedures on the cervical disk with a percutaneous anterior approach. Pain visual analogue scale (VAS) scores, patient responses stating significant (≥50%) pain relief, significant (≥50%) reduction in pain medicine intake and Modified MacNab criteria were adopted to evaluate the pain intensity, degree of pain relief, and functional status after 12 months of follow-up.The preoperative pain VAS score was 6.5 ± 1.1 (95% confidence interval [CI] 6.085-6.915), and the pain VAS score significantly decreased to 2.4 ± 1.3 (95% CI 1.929-2.928), 2.5 ± 1.5 (95% CI 1.963-3.109), 2.7 ± 1.4 (95% CI 2.157-3.271), 3.1 ± 1.6 (95% CI 2.457-3.686), and 3.1 ± 1.6 (95% CI 2.471-3.743) at 1 week and 1, 3, 6, and 12 months postoperatively, respectively (P < 0.05). Twenty-two (78.6%), 21 (75.0%), 20 (71.4%), 19 (67.9%), and 18 (64.3%) of the patients expressed significant pain relief at 1 week and 1, 3, 6, and 12 months postoperatively, respectively. 24 (85.7%), 23 (82.1%), 23 (82.1%), and 22 (78.6%) reported significant reduction in pain medication intake at 1, 3, 6, and 12 months postoperatively, respectively. According to the Modified MacNab criteria, the numbers of patients with "excellent" or "good" ratings were 22 (78.6%), 21 (75.0%), 20 (71.4%), and 18 (64.3%) at 1, 3, 6, and 12 months postoperatively, respectively. No serious complications were observed.The findings of this study showed that coblation is an effective, safe, minimally invasive, and less uncomfortable procedure for the treatment of discogenic upper back pain.

Efficacy of coblation annuloplasty in discogenic low back pain: a prospective observational study

In degenerative disc, the innervated outer annulus is confirmed to the major origin resulted in discogenic pain. To alleviate the discogenic pain, annuloplasty with electrothermal technology was proved to be effective, which mainly involves the thermal heating of the annulus to denature collagen fibers and denervate posterior annular nerve fibers. However, little is known that efficacy of annuloplasty with coblation technology in treating discogenic pain through directly interrupting nerves in outer annulus.The purpose of this study was to evaluate the clinical outcomes of coblation annuloplasty for the treatment of discogenic low back pain.In a clinical prospective observational study, 17 consecutive patients with discogenic low back pain underwent coblation annuloplasty under local anesthesia. Pain visual analogue scale (VAS) scores, patient responses stating significant (≥50%) pain relief, and modified MacNab criteria were adopted to evaluate the pain intensity, degree of pain relief, and functional status after 6 months of follow-up.The preoperative pain VAS score was 6.5 ± 0.8(95% confidence interval [CI] 6.1-6.9) and the pain VAS score decreased to 2.9 ± 1.6 (95% CI 2.1-3.8), 2.9 ± 1.7 (95% CI 2.1-3.8), 3.2 ± 1.6 (95% CI 2.4-4.1), 3.2 ± 1.7 (95% CI 2.4-4.2) at 1 week and 1, 3 and 6 month postoperatively, respectively. 12 (70.6%), 11 (64.7%), 10 (58.8%) and 10 (58.8%) of patients reported significant pain relief at 1 week and 1, 3 and 6 months postoperatively. At 1, 3, and 6 months postoperatively, the numbers of patients with "excellent" or "good" ratings were 13 (76.5%), 11 (64.7%), and 10 (58.8%) according to the modified MacNab criteria. No serious complications were observed.The finds show that coblation annuloplasty is an effective, safe, and less uncomfortable procedure in managing discogenic low back pain.

Current trends in biologics delivery to restore intervertebral disc anabolism

Low back pain is generally attributed to intervertebral disc (IVD) degeneration. This is a multifactorial disease induced by genetic and environmental factors and that progresses with aging. Disc degeneration is characterized by a limited ability of IVD cells to produce functional matrix while producing abnormal amounts of matrix-degrading enzymes. The prolonged imbalance between anabolism and catabolism in degenerative discs alters their composition and hydration. In turn, this results in increased angiogenesis and the loss of the disc's ability to maintain its aneural condition. Inflammation in the IVD, in particular the presence of pro-inflammatory cytokines, was found to favor innervation and also sensitization of the nociceptive pathways, thereby exacerbating degenerative symptoms. In this review, we discuss anti-inflammatory approaches to encounter disc catabolism, potential treatments to lower discogenic pain and pro-anabolic approaches in the form of protein delivery, gene therapy and cell delivery, to trigger regeneration in the IVD.

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.

Blocking the mineralocorticoid receptor improves effectiveness of steroid treatment for low back pain in rats

BACKGROUND

Localized inflammation of lumbar dorsal root ganglia (DRG) may contribute to low back pain. Local injections of corticosteroids used for low back pain are sometimes ineffective. Many corticosteroids activate not only the target glucocorticoid receptor (GR) but also the mineralocorticoid receptor (MR), which may have proinflammatory effects countering the effects of GR activation.

METHODS

A low back pain model was implemented in rats (n = 6 to 10 per group) by locally inflaming the L5 DRG. Sensory neuron excitability and mechanical hypersensitivity of the hind paws were measured. Tested steroids were applied locally to the inflamed DRG or orally.

RESULTS

The selective MR blocker eplerenone reduced pain behaviors when given orally starting at the time of surgery, or starting 7 days later. The highly GR-selective agonist fluticasone, applied locally to the inflamed DRG, was much more effective in reducing mechanical hypersensitivity. The MR/GR agonist 6-α methylprednisolone, commonly injected for low back pain, reduced mechanical hypersensitivity when applied locally to the DRG but was less effective than fluticasone. Its effectiveness was improved by combining it with local eplerenone. All tested steroids reduced hyperexcitability of myelinated sensory neurons (n = 71 to 220 cells per group) after inflammation, particularly abnormal spontaneous activity.

CONCLUSIONS

This preclinical study indicates the MR may play an important role in low back pain involving inflammation. Some MR effects may occur at the level of the sensory neuron. It may be useful to consider the action of clinically used steroids at the MR as well as at the GR.

Nerve growth factor increases MMP9 activity in annulus fibrosus cells by upregulating lipocalin 2 expression

PURPOSE

Nerve growth factor (NGF) expression and activity is important in chronic lower back pain but may also act as a pro-catabolic factor in the pathogenesis of intervertebral disc (IVD) degeneration. Lipocalin 2 (Lcn2) expression in IVD was upregulated by NGF stimulation in our previous study. The current study was undertaken to identify potential mechanisms of the latter effect including potential interactions between Lcn2 and matrix metalloproteinase 9 (MMP9).

METHODS

Rat annulus fibrosus (AF) cells were stimulated by NGF and subjected to microarray analysis, subsequent real-time PCR, western immunoblotting, and immunofluorescence. Cells were treated with NGF in the absence or presence of the NGF inhibitor Ro 08-2750. Zymography and functional MMP9 assays were used to determine MMP9 activity, whilst the dimethyl-methylene blue assay was used to quantify the release of glycosaminoglycans (GAGs) reflecting catabolic effects following NGF treatment. Immunoprecipitation with immunoblotting was used to identify interactions between MMP9 and Lcn2.

RESULTS

Increased expression of Lcn2 gene and protein following NGF stimulation was confirmed by microarray analysis, real-time PCR, western blot and immunofluorescence. Zymography showed that NGF enhanced 125-kDa gelatinase activity, identified as a Lcn2/MMP9 complex by immunoprecipitation and immunoblotting. Functional assays showed increased MMP9 activity and GAG release in the presence of NGF. The effects of NGF were neutralized by the presence of Ro 08-2750.

CONCLUSIONS

NGF upregulates Lcn2 expression and increases MMP9 activity in AF cells; processes which are likely to potentiate degeneration of AF tissue in vivo. Anti-NGF treatment may have benefit for management of pain relief and slowing down progression of AF tissue degeneration.

The etiologies of low back pain in patients with lumbar disk herniation

BACKGROUND

Low back pain (LBP) is a common complaint in population that lowers the quality of life. The main etiology of LBP is recognized in about 20% of patients while it is attributed to lumbar disk herniation (LDH) in 80% of cases and causes some unnecessary lumbar surgeries without realizing the definite cause.

OBJECTIVES

This study was planned to evaluate the etiologies of LBP in patients who had LDH to clarify whether the disc herniation is the main cause of patients` pain or other diseases were responsible for this kind of pain.

MATERIALS AND METHODS

In this cross-sectional study, we analyzed the medical profiles of the patients with proven LDH in a private clinic in Mashhad City, Iran, between 2005 and 2012, for demographic and the etiologies of LBP with clinical and paraclinical studies. We also calculated the incidence of each etiology by SPSS 13.

RESULTS

In our study, among 1250 patients with proven LDH by MRI, 500 patients (40%) had chronic LBP and the most common causes of LBP were heavy constant working (40.2%), osteoporosis (35.6%), and sacroiliac joint pain (34.6%), consecutively. Interestingly, LDH had the ninth rank among the common cause of LBP.

CONCLUSIONS

In this study, we found that in spite of previous beliefs, discopathies were not common etiologies of LBP. Thus, even in patients with proven LDH by imaging studies, the physician should perform a thorough evaluation for other causes of LBP to avoid unnecessary lumbar surgeries.

Nerve growth factor promotes expression of novel genes in intervertebral disc cells that regulate tissue degradation: Laboratory investigation

OBJECT

Increased neurotrophin activity in degenerative intervertebral discs (IVDs) is one potential cause of chronic low-back pain (LBP). The aim of the study was to assess if nerve growth factor (NGF) might alter gene expression of IVD cells and contribute to disc degeneration by enhancing expression or activity of factors that cause breakdown of IVD matrix.

METHODS

Rat-tail IVD cells were stimulated by NGF and subjected to microarray analysis. Real-time polymerase chain reaction, Western blotting, and immunocytochemistry of rat and human IVD cells and tissues treated with NGF in vitro in the absence or presence of the NGF inhibitor Ro 08-2750 were used to confirm findings of the microarray studies. Phosphorylation of mitogen-activated protein kinase (MAPK) was used to identify cell signaling pathways involved in NGF stimulation in the absence or presence of Ro 08-2750.

RESULTS

Microarray analysis demonstrated increased expression of chitinase 3-like 1 (Chi3l1), lipocalin 2 (Lcn2), and matrix metalloproteinase-3 (Mmp3) following NGF stimulation of rat IVD cells in vitro. Increased gene expression was confirmed by real-time polymerase chain reaction with a relative increase in the Mmp/Timp ratio. Increased expression of Chi3l1, Lcn2, and Mmp3 following NGF stimulation was also demonstrated in rat cells and human tissue in vitro. Effects of NGF on protein expression were blocked by an NGF inhibitor and appear to function through the extracellular-regulation kinase 1/2 (ERK1/2) MAPK pathway.

CONCLUSIONS

Nerve growth factor has potential effects on matrix turnover activity and influences the catabolic/anabolic balance of IVD cells in an adverse way that may potentiate IVD degeneration. Anti-NGF treatment might be beneficial to ameliorate progressive tissue breakdown in IVD degeneration and may lead to pain relief.

Comparison between pain at discography and morphological disc changes at axial loaded MRI in patients with low back pain

PURPOSE

Discogenic pain is induced by axial load, but there are no studies evaluating the influence of dynamic MRI in relation to provoked pain at discography. The aim of this study was to investigate the relationship between discography-induced pain and morphological disc changes, occurring during axial loaded MRI (alMRI). A secondary aim was to compare and register the frequency of provoked concordant pain at alMRI and discography.

METHODS

41 patients with assumed discogenic pain were investigated with MRI, alMRI and pressure-controlled discography (PCD) (119 discs). Provoked pain at both discography and alMRI was classified as concordant or discordant with daily pain as reference. A concordant discogram required pain intensity ≥5/10 (numerical rating scale) at ≤50 psi and one negative control disc. A concordant provocation at alMRI required pain intensity ≥5/10. The relationship between concordant pain at discography and morphological disc measures (degeneration, height, bulge, angle, area, and circumference) at MRI/alMRI was investigated.

RESULTS

Changes in the morphological appearance occurred in at least one disc level in all patients when loaded and unloaded MRI were compared. However, no significant differences between concordant and discordant discograms in terms of morphological disc features at conventional MRI or alMRI were found. 78 % of the patients reported concordant provoked pain during the alMRI.

CONCLUSIONS

In the majority of patients with low back pain, discography as well as alMRI provoked concordant pain. Loading of the spine, alMRI, revealed however no clinically useful morphological characteristics in the discs with concordant discograms. Alternative or more sensitive diagnostic methods are needed to understand load-induced discogenic pain.

Pressure Increase in Adjacent Discs During Clinical Discography Questions the Methods Validity

STUDY DESIGN

Observational in vivo clinical study.

OBJECTIVE

To investigate whether intradiscal pressure is transferred to adjacent discs during clinical discography in subjects with discogenic pain.

SUMMARY OF BACKGROUND DATA

Despite the introduction of pressure registration in discography, the validity of the method remains controversial. Discography in vivo in anesthetized pigs has shown that the pressure increase during disc injection is transmitted to adjacent discs. If pressure transmission is confirmed in human spines, it could be a potential source of false-positive discography responses.

METHODS

Twenty-five discograms were performed in 9 consecutive patients. A pressure sensor was introduced through a 22-gauge needle into the nucleus pulposus in 2 adjacent discs. Contrast was injected with a manometer (∼0.05 mL/s) into one of the discs, whereas intradiscal pressure was measured simultaneously in both discs. The injection continued until one of the endpoints was reached; concordant pain with an intensity of 5/10 or more, intradiscal pressure of 80 psi (absolute pressure), and/or 3.5-mL contrast volume.

RESULTS

Intradiscal pressure was successfully measured in 22 adjacent discs of which 7 were not filled with contrast and 15 were prefilled from the previous discogram. A mean pressure increase of 13 psi (range, 3-42 psi) was recorded in 55% (12) of the adjacent discs, corresponding to an increase of 62% above baseline. Of discograms inducing pressure transmission, all had Pfirrmann degeneration grade of 3 or more and, of adjacent discs with increased pressure, 75% had degeneration of 3 or more. Maximum pressure in injected discs averaged 35 psi above opening pressure (range, 10-69 psi).

CONCLUSION

Clinical discography induces a pressure increase in adjacent discs. The induced pressure increase was of a clinically relevant magnitude and was evident despite low absolute pressures in the injected disc. Pressure transmission during discography constitutes a potential major source of false-positive responses, questioning the ability of discography to provoke pain at just a single disc level.

LEVEL OF EVIDENCE

1.

The efficacy of manual therapy and exercise for different stages of non-specific low back pain: an update of systematic reviews

OBJECTIVE

to review and update the evidence for different forms of manual therapy (MT) for patients with different stages of non-specific low back pain (LBP).

DATA SOURCES

MEDLINE, Cochrane-Register-of-Controlled-Trials, PEDro, EMBASE.

METHOD

A systematic review of MT with a literature search covering the period of January 2000 to April 2013 was conducted by two independent reviewers according to Cochrane and PRISMA guidelines. A total of 360 studies were evaluated using qualitative criteria. Two stages of LBP were categorized; combined acute-subacute and chronic. Further sub-classification was made according to MT intervention: MT1 (manipulation); MT2 (mobilization and soft-tissue-techniques); and MT3 (MT1 combined with MT2). In each sub-category, MT could be combined or not with exercise or usual medical care (UMC). Consequently, quantitative evaluation criteria were applied to 56 eligible randomized controlled trials (RCTs), and hence 23 low-risk of bias RCTs were identified for review. Only studies providing new updated information (11/23 RCTs) are presented here.

RESULTS

Acute-subacute LBP: STRONG-evidence in favour of MT1 when compared to sham for pain, function and health improvements in the short-term (1-3 months). MODERATE-evidence to support MT1 and MT3 combined with UMC in comparison to UMC alone for pain, function and health improvements in the short-term. Chronic LBP: MODERATE to STRONG-evidence in favour of MT1 in comparison to sham for pain, function and overall-health in the short-term. MODERATE-evidence in favour of MT3 combined with exercise or UMC in comparison to exercise and back-school was established for pain, function and quality-of-life in the short and long-term. LIMITED-evidence in favour of MT2 combined with exercise and UMC in comparison to UMC alone for pain and function from short to long-term. LIMITED-evidence of no effect for MT1 with extension-exercise compared to extension-exercise alone for pain in the short to long-term.

CONCLUSION

This systematic review updates the evidence for MT with exercise or UMC for different stages of LBP and provides recommendations for future studies.

In vivo discography in degenerate porcine spines revealed pressure transfer to adjacent discs

STUDY DESIGN

In vivo experimental porcine study.

OBJECTIVE

To investigate if discography induced pressure increase in adjacent degenerate discs.

SUMMARY OF BACKGROUND DATA

Despite refinements in the past 2 decades, the validity of discography is debated. Discography in healthy pigs has shown that the pressure increase during disc injection transmits to adjacent discs, a potential source for false positive responses.

METHODS

Degeneration in 1 lumbar disc was induced in 10 pigs by drilling a hole through the endplate. Intradiscal pressure was recorded using a 0.36-mm fiber-optic pressure transducer inserted into nucleus pulposus through a 22-gauge needle. The pressure was measured simultaneously in 2 adjacent discs during slow (0.03 mL/s) automated contrast injection into 1 of the discs up to 8 bar (116 psi). Ten adjacent discs were prefilled with contrast from previous discogram. A pressure increase 2 psi or more above baseline was defined as increased pressure in adjacent discs. Pressure was recorded until 15 minutes after injection.

RESULTS

A total of 28 discograms were successfully performed. A pressure increase during injection was detected in 57% (16) of the 28 adjacent discs with mean 3.2 psi (1.7-8.2; standard deviation, 1.8), corresponding to a mean increase above baseline of 11%. Of those 16 adjacent discs, 4 were nondegenerate and 12 degenerate, of which 7 were prefilled. Fifteen minutes after injection, 89% of adjacent discs displayed increase in pressure of mean 14% above baseline.

CONCLUSION

Discography induced pressure increase in adjacent discs in a degenerate disc model, something not reported earlier. If present, also in human spine pressure transmission, may be a potential cause for false positive discography responses.

Discogenic axial back pain: is there a role for nucleoplasty?

Study Design

A prospective observational study.

Purpose

To evaluate the role of nucleoplasty in the management of discogenic axial back pain; to determine the influence of concordant pain during provocative discography, annular tear and loss of disc height on the outcome of nucleoplasty.

Overview of Literature

The role of nucleoplasty in the management of radicular leg pain due to disc herniation is known. However, the data regarding its role in the management of discogenic axial back pain is scarce.

Methods

A prospective evaluation of 30 patients with discogenic axial back pain undergoing nucleoplasty was performed. Pain, functional disability and quality of life were assessed using the 100 mm visual analogue scale (VAS), Oswestry Disability Index (ODI) and Short Form-36 (SF-36), respectively.

Results

The mean reduction in VAS was 31.03 and 29.03; mean reduction in ODI was 24.53 and 20.60; and mean increment in SF-36 was 13.58 and 12.30, at 6 months and at 12 months, respectively. The differences were statistically significant (p <0.05). Concordant pain during provocative discography, annular tear and loss of disc height did not affect a clinically significant improvement in any of the three outcomes (p =0.882, 0.213, and 0.170; respectively).

Conclusions

Nucleoplasty produced statistically significant improvements in pain, functional disability and quality of life in patients with discogenic low back pain at 6 months and at 12 months. Concordant pain during provocative discography, annular tear and loss of disc height did not influence any of the outcomes after nucleoplasty in patients with discogenic axial back pain.

Belief reinforcement: one reason why costs for low back pain have not decreased

Recent figures show that there has been no change in the upward trend of direct and indirect costs for the largely benign symptom of low back pain in Western societies. This is despite greater understanding and the recommendation of a much more conservative and independent approach to its management. Moreover, in recent years, several large-scale education programs that aim to bring knowledge of the public (including general practitioners) more in line with evidence-based best practice were carried out in different countries. The hope was that the information imparted would change beliefs, ie, dysfunctional patient behavior and biomedical practice on the part of clinicians. However, these programs had no influence on behavior or costs in three out of the four countries in which they were implemented. It is argued that one reason for the overall lack of success is that it is extremely difficult to alter the potentially disabling belief among the lay public that low back pain has a structural mechanical cause. An important reason for this is that this belief continues to be regularly reinforced by the conditions of care of a range of "hands-on" providers, for whom idiosyncratic variations of that view are fundamental to their professional existence.

The potential impact of various diagnostic strategies in cases of chronic pain syndromes associated with lumbar spine degeneration

PURPOSE

To study the possible effects of various diagnostic strategies and the relative contribution of various structures in order to determine the optimal diagnostic strategy in treating patients with noncompressive pain syndromes.

STUDY DESIGN

Prospective, nonrandomized cohort study of 83 consecutive patients with noncompressive pain syndromes resistant to repeated courses of conservative treatment. The follow-up period was 18 months.

RESULTS

Nucleoplasty was effective in cases of discogenic pain; the consequences related to false positive results of the discography were significant. The most specific criterion was 80% pain relief after facet joint blocks, whereas 50% pain relief and any subjective pain relief were not associated with a significant increase in the success rate. A considerable rate of false negative results was associated with 80% pain relief, whereas 50% pain relief after facet joint blocks showed the optimal ratio of sensitivity and specificity. Facet joint pain was detected in 50.6% of cases (95% confidence interval 44.1%-66.3%), discogenic pain in 16.9% cases (95% confidence interval 9.5%-26.7%), and sacroiliac joint pain in 7.2% cases (95% confidence interval 2.7%-15%). It was impossible to differentiate the main source of pain in 25.3% of cases.

CONCLUSION

It is rational to adjust the diagnostic algorithm to the probability of detecting a particular pain source and, in doing so, reduce the number of invasive diagnostic measures to evaluate a pain source. False positive results of diagnostic measures can negatively affect the overall efficacy of a particular technology; therefore, all reasons for the failure should be studied in order to reach an unbiased conclusion. In choosing diagnostic criteria, not only should the success rate of a particular technology be taken into consideration but also the rate of false negative results. Acceptable diagnostic criteria should be based on a rational balance of sensitivity and specificity.

Lumbar spine fusion for chronic low back pain due to degenerative disc disease: a systematic review

STUDY DESIGN

Systematic literature review.

OBJECTIVE

To categorize published evidence systematically for lumbar fusion for chronic low back pain (LBP) in order to provide an updated and comprehensive analysis of the clinical outcomes.

SUMMARY OF BACKGROUND DATA

Despite a large number of publications of outcomes of spinal fusion surgery for chronic LBP, there is little consensus on efficacy.

METHODS

A MEDLINE and Cochrane database search was performed to identify published articles reporting on validated patient-reported clinical outcomes measures (2 or more of visual analogue scale, Oswestry Disability Index, Short Form [36] Health Survey [SF-36] PCS, and patient satisfaction) with minimum 12 months of follow-up after lumbar fusion surgery in adult patients with LBP due to degenerative disc disease. Twenty-six total articles were identified and stratified by level of evidence: 18 level 1 (6 studies of surgery vs. nonoperative treatment, 12 studies of alternative surgical procedures), 2 level 2, 2 level 3, and 4 level 4 (2 prospective, 2 retrospective). Weighted averages of each outcomes measure were computed and compared with established minimal clinically important difference values.

RESULTS

Fusion cohorts included a total of 3060 patients. The weighted average improvement in visual analogue scale back pain was 36.8/100 (standard deviation [SD], 14.8); in Oswestry Disability Index 22.2 (SD, 14.1); in SF-36 Physical Component Scale 12.5 (SD, 4.3). Patient satisfaction averaged 71.1% (SD, 5.2%) across studies. Radiographical fusion rates averaged 89.1% (SD, 13.5%), and reoperation rates 12.5% (SD, 12.4%) overall, 9.2% (SD, 7.5%) at the index level. The results of the collective studies did not differ statistically in any of the outcome measures based on level of evidence (analysis of variance, P > 0.05).

CONCLUSION

The body of literature supports fusion surgery as a viable treatment option for reducing pain and improving function in patients with chronic LBP refractory to nonsurgical care when a diagnosis of disc degeneration can be made.

Disc volume reduction with percutaneous nucleoplasty in an animal model

Study Design

We assessed volume following nucleoplasty disc decompression in lower lumbar spines from cadaveric pigs using 7.1Tesla magnetic resonance imaging (MRI).

Purpose

To investigate coblation-induced volume reductions as a possible mechanism underlying nucleoplasty.

Methods

We assessed volume following nucleoplastic disc decompression in pig spines using 7.1-Tesla MRI. Volumetry was performed in lumbar discs of 21 postmortem pigs. A preoperative image data set was obtained, volume was determined, and either disc decompression or placebo therapy was performed in a randomized manner. Group 1 (nucleoplasty group) was treated according to the usual nucleoplasty protocol with coblation current applied to 6 channels for 10 seconds each in an application field of 360°; in group 2 (placebo group) the same procedure was performed but without coblation current. After the procedure, a second data set was generated and volumes calculated and matched with the preoperative measurements in a blinded manner. To analyze the effectiveness of nucleoplasty, volumes between treatment and placebo groups were compared.

Results

The average preoperative nucleus volume was 0.994 ml (SD: 0.298 ml). In the nucleoplasty group (n = 21) volume was reduced by an average of 0.087 ml (SD: 0.110 ml) or 7.14%. In the placebo group (n = 21) volume was increased by an average of 0.075 ml (SD: 0.075 ml) or 8.94%. The average nucleoplasty-induced volume reduction was 0.162 ml (SD: 0.124 ml) or 16.08%. Volume reduction in lumbar discs was significant in favor of the nucleoplasty group (p<0.0001).

Conclusions

Our study demonstrates that nucleoplasty has a volume-reducing effect on the lumbar nucleus pulposus in an animal model. Furthermore, we show the volume reduction to be a coblation effect of nucleoplasty in porcine discs.

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.

Physical exercise affects cell proliferation in lumbar intervertebral disc regions in rats

STUDY DESIGN

Descriptive experimental study.

OBJECTIVE

The aim of this study was to investigate the effect of exercise on cell proliferation in different areas of the intervertebral disc (IVD) and recruitment of cells possibly active in regeneration of normal rat lumbar IVDs.

SUMMARY OF BACKGROUND DATA

Little is known about the effects of physical exercise on lumbar IVD tissue. Recently, stem cell niches in the perichondrium area of the IVD were identified and cells in these niches have been suggested to be involved in the normal regeneration of the IVD.

METHODS

Thirty Sprague-Dawley rats were exposed to 5-bromo-2-deoxyuridine (BrdU) diluted in the drinking water during 14 days. Fifteen rats ran on a treadmill daily for 50 min/d, 5 d/wk (exercise group), and 15 nonexercised rats served as controls. Immunohistochemical analyses (anti-BrdU antibody) were performed at 9, 14, 28, 56, and 105 days after the start of the exercise protocol. BrdU positive cells were counted in the stem cell niche area, the peripheral region of epiphyseal cartilage area, and the annulus fibrous outer and inner areas. Data were analyzed by 2-way analysis of variance (significance level; P < 0.05).

RESULTS

The BrdU positive cell numbers in the stem cell niche and annulus fibrous outer regions were increased in discs from the exercising group on days 14 (P < 0.01) and 105 (P < 0.05) and at day 14 (P < 0.01) in the peripheral epiphyseal cartilage region compared with controls.

CONCLUSION

Physical exercise was shown to have positive effects on cell proliferation in IVDs, with involvement of various disc regions, indicating a differential response by disc tissue to exercise depending on anatomical location and tissue characteristics.

Percutaneous disc decompression with nucleoplasty-volumetry of the nucleus pulposus using ultrahigh-field MRI

PURPOSE

To evaluate changes in nucleus pulposus volume as a potential parameter for the effects of disc decompression.

METHODS

Fifty-two discs (T8 to L1) were extracted from 26 pigs and separated into thoracic (T8 to T11) and thoracolumbar discs (T12 to L1). The discs were imaged using 7.1 Tesla ultrahigh-field magnetic resonance imaging (MRI) with acquisition of axial T2-weighted turbo spin-echo sequences for determination of baseline and postinterventional nucleus pulposus volumes. Volumes were calculated using OsiriX® (http://www.osirix-viewer.com). After randomization, one group was treated with nucleoplasty, while the placebo group was treated with an identical procedure but without coblation current. The readers analyzing the MR images were blinded to the kind of procedure performed. Baseline and postinterventional volumes were compared between the nucleoplasty and placebo group.

RESULTS

Average preinterventional nucleus volume was 0.799 (SD: 0.212) ml. Postinterventional volume reduction in the nucleoplasty group was significant at 0.052 (SD: 0.035) ml or 6.30% (p<0.0001) (thoracic discs) and 0.082 (SD: 0.042) ml or 7.25% (p = 0.0078) (thoracolumbar discs). Nucleoplasty achieved volume reductions of 0.114 (SD: 0.054) ml or 14.72% (thoracic) and 0.093 (SD: 0.081) ml or 11.61% (thoracolumbar) compared with the placebo group.

CONCLUSIONS

Nucleoplasty significantly reduces thoracic and thoracolumbar nucleus pulposus volumes in porcine discs.

Intradiscal pulsed radiofrequency application following provocative discography for the management of degenerative disc disease and concordant pain: a pilot study

The development of diagnostic criteria and the use of provocative discography allow identifying the degenerative disc as causative structure for chronic low-back pain. Unfortunately, none of the available interventional treatment options have been demonstrated to be effective over a prolonged period of time for a considerable number of patients. Pathophysiological studies indicate sprouting of sensory nerves and inflammatory processes as underlying pain mechanisms. Pulsed radiofrequency (PRF) treatment in small and larger joints was described to reduce pain and improve healing by stimulating the immunology. Earlier findings of PRF applied in the disc annulus were promising. It is assumed that PRF applied in the nucleus would change the conductivity of nerve endings and provide a clinically relevant pain reduction. The application of the electric field of PRF in the disc may also activate the immune system, thus reducing the inflammation process of chronic pain. Pulsed radiofrequency in the nucleus was studied in 76 patients with discogenic pain confirmed by magnetic resonance imaging and provocative discography. At 3-month follow-up, 38% of the patients had > 50% pain reduction, at 12 month the effect is maintained in 29%. In patients with unsatisfactory pain relief 3 months after the intervention, secondary pain sources may have been revealed. The latter were treated accordingly. Of all patients, 56% had > 50% pain reduction 1 year after first treatment. Our findings suggest that PRF in the nucleus may be considered for patients with proven discogenic pain. A randomized controlled trial to confirm our findings is justified.▪