A critical evaluation of discography in patients with lumbar intervertebral disc disease

MRI-based measurement of in vivo disc mechanics in a young population due to flexion, extension, and diurnal loading

Background

Intervertebral disc degeneration is often implicated in low back pain; however, discs with structural degeneration often do not cause pain. It may be that disc mechanics can provide better diagnosis and identification of the pain source. In cadaveric testing, the degenerated disc has altered mechanics, but in vivo, disc mechanics remain unknown. To measure in vivo disc mechanics, noninvasive methods must be developed to apply and measure physiological deformations.

Aim

Thus, this study aimed to develop methods to measure disc mechanical function via noninvasive MRI during flexion and extension and after diurnal loading in a young population. This data will serve as baseline disc mechanics to later compare across ages and in patients.

Materials & Methods

To accomplish this, subjects were imaged in the morning in a reference supine position, in flexion, in extension, and at the end of the day in a supine position. Disc deformations and vertebral motions were used to quantify disc axial strain, changes in wedge angle, and anterior-posterior (A-P) shear displacement. T2 weighted MRI was also used to evaluate disc degeneration via Pfirrmann grading and T2 time. All measures were then tested for effect of sex and disc level.

Results

We found that flexion and extension caused level-dependent strains in the anterior and posterior of the disc, changes in wedge angle, and A-P shear displacements. Flexion had higher magnitude changes overall. Diurnal loading did not cause level-dependent strains but did cause small level-dependent changes in wedge angle and A-P shear displacements.

Discussion

Correlations between disc degeneration and mechanics were largest in flexion, likely due to the smaller contribution of the facet joints in this condition.

Conclusion

In summary, this study established methods to measure in vivo disc mechanical function via noninvasive MRI and established a baseline in a young population that may be compared to older subjects and clinical disorders in the future.

Guideline summary review: an evidence-based clinical guideline for the diagnosis and treatment of low back pain

BACKGROUND CONTEXT

The North American Spine Society's (NASS) Evidence Based Clinical Guideline for the Diagnosis and Treatment of Low Back Pain features evidence-based recommendations for diagnosing and treating adult patients with nonspecific low back pain. The guideline is intended to reflect contemporary treatment concepts for nonspecific low back pain as reflected in the highest quality clinical literature available on this subject as of February 2016.

PURPOSE

The purpose of the guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for adult patients with nonspecific low back pain. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition.

STUDY DESIGN

This is a guideline summary review.

METHODS

This guideline is the product of the Low Back Pain Work Group of NASS' Evidence-Based Clinical Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members utilized NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guideline was submitted to an internal and external peer review process and ultimately approved by the NASS Board of Directors.

RESULTS

Eighty-two clinical questions were addressed, and the answers are summarized in this article. The respective recommendations were graded according to the levels of evidence of the supporting literature.

CONCLUSIONS

The evidence-based clinical guideline has been created using techniques of evidence-based medicine and best available evidence to aid practitioners in the diagnosis and treatment of adult patients with nonspecific low back pain. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flowchart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx.

Selective Anterior Lumbar Interbody Fusion for Low Back Pain Associated With Degenerative Disc Disease Versus Nonsurgical Management

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

To evaluate the long-term outcomes of selective one- to two-level anterior lumbar interbody fusions (ALIFs) in the lower lumbar spine versus continued nonsurgical management.

SUMMARY OF BACKGROUND DATA

Low back pain associated with lumbar intervertebral disc degeneration is common with substantial economic impact, yet treatment remains controversial. Surgical fusion has previously provided mixed results with limited durable improvement of pain and function.

METHODS

Seventy-five patients with one or two levels of symptomatic Pfirrmann grades 3 to 5 disc degeneration from L3-S1 were identified. All patients had failed at least 6 months of nonsurgical treatment. Forty-two patients underwent one- or two-level ALIFs; 33 continued multimodal nonsurgical care. Patients were evaluated radiographically and the visual analog pain scale (VAS), Oswestry Disability Index (ODI), EuroQol five dimensions (EQ-5D), and Patient-Reported Outcomes Measurement Information System scores for pain interference, pain intensity, and anxiety. As-treated analysis was performed to evaluate outcomes at a mean follow-up of 7.4 years (range: 2.5-12).

RESULTS

There were no differences in pretreatment demographics or nonsurgical therapy utilization between study arms. At final follow-up, the surgical arm demonstrated lower VAS, ODI, EQ-5D, and Patient-Reported Outcomes Measurement Information System pain intensity scores versus the nonsurgical arm. VAS and ODI scores improved 52.3% and 51.1% in the surgical arm, respectively, versus 15.8% and -0.8% in the nonsurgical arm. Single-level fusions demonstrated improved outcomes versus two-level fusions. The pseudarthrosis rate was 6.5%, with one patient undergoing reoperation. Asymptomatic adjacent segment degeneration was identified in 11.9% of patients.

CONCLUSION

Selective ALIF limited to one or two levels in the lower lumbar spine provided improved pain and function when compared with continued nonsurgical care. ALIF may be a safe and effective treatment for low back pain associated with disc degeneration in select patients who fail nonsurgical management.

LEVEL OF EVIDENCE

3.

Analysis of the clinical picture in patients with osteoarthritis of the spine depending on the type and severity of lesions on magnetic resonance imaging

OBJECTIVES

Spondyloarthritis is the most common pathological change in the spine. In a significant number of cases, it leads to compression of the nervous structures of the spinal canal, causing pain and neurological symptoms. Intervertebral disc pathology is a common cause of root deficits in neurological examination of all types of degenerative changes of the spine structures. Disc herniation is pathologically divided into 4 stages of herniated nucleus pulposus: 1) bulging, 2) protrusion, 3) extrusion, 4) sequestration. The aim of this study is to analyze the correlation between the type and severity of degenerative changes in the spine and the incidence of neurological deficits.

MATERIAL AND METHODS

The study included 100 patients: 74 men and 26 women aged 50.2 ±10.43 years with pain of the spine in the cervical and/or lumbosacral segments and with degenerative changes in the plain radiographs. The mean value of body mass index (BMI) was 27.8 ±3.95 kg/m(2). Each patient underwent neurological examinations and 1.5 T magnetic resonance imaging MRI of the cervical and/or lumbar spine.

RESULTS

Every patient was diagnosed with herniated nucleus pulposus affecting on average 4 ±2 segments of the spine. The most frequently observed degree of severity of disc herniation was the second (protrusion, 71.9% of all disc disease in 89 patients). Much less frequently found was the third degree (extrusion, 45 patients, 20.1% slipped disc), the first (bulging, 14 patients, 6.3% slipped disc), and least often only a small percentage of fourth degree (sequestration, 4 patients, 1.7% slipped disc). Neurological symptoms (deficits) were observed in 34 patients. They were accompanied by disc herniations in 23.7% of patients. In remaining patients with neurological deficits there was spinal stenosis. No correlation was observed between neurological deficits and stage 1 of disc herniation.

CONCLUSIONS

The incidence rate of neurological deficits is correlated with the degree of changes in the spine, as visualized by MRI.

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.

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.

Diagnosis of discogenic low back pain in patients with probable symptoms but negative discography

OBJECTIVE

The purpose of the current study was to determine, whenever the patients complained of probable symptoms of discogenic low back pain and had obvious disc pathological changes on magnetic resonance imaging (MRI) but showed negative in discography, whether we could absolutely exclude the diagnosis of discogenic pain or not.

METHODS

The patients we selected in our study had only one segmental disc pathology on MRI for the purpose of minimizing the interference and all patients complained of probable discogenic pain symptoms. Some special lumbar diseases were excluded by physical examination and CT or MRI scan. Finally, 45 isolated patients with negative discography were enrolled in our study from January 2006 to June 2008. Twenty-three patients were randomly distributed in experimental group, who underwent provocative discography plus intradiscal injection of dexamethasone (5 mg in each patient), while the other 22 patients in the control group received intradiscal injection of saline as a placebo. Visual analog scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the changes of pain and function after discography.

RESULTS

The mean age of the 16 male and 29 female patients was 44.9 years, whose main clinical manifestations included axial back pain (100%), pain in the region of Groin (33.3%), pain in the anterior or posterior region of thigh (42.2%), buttock pain (24.4%) and lower extremity pain (11.1%), and among them L3-L4 pathological disc was found in three patient, L4-L5 pathological disc in 28 patients and L5-S1 pathological disc in 14 patients. Discography and CT scans of the 45 patients revealed that there were grade 5 in 38 discs and grade 4 in seven discs by means of Modified Dallas classification. After about 6-month follow-up, the results showed that VAS scores and ODI scores were greatly improved during the first 3-month follow-up in the experimental group compared with pre-discography and between groups (p < 0.05), but no statistically significant difference after 24-week follow-up (p > 0.05). The probable symptoms of discogenic low back pain were significantly improved in the experimental group in the short term.

CONCLUSION

The study indicated that negative discography in patients with probable symptoms of discogenic low back pain cannot absolutely exclude the diagnosis of discogenic pain. Patients of this kind may suffer from other diseases, but we cannot ignore the existence of discogenic pain.

Is the fibronectin-aggrecan complex present in cervical disk disease?

OBJECTIVE

To investigate the presence of inflammatory cytokines and the fibronectin-aggrecan complex (FAC) in persons undergoing surgical treatment for cervical radiculopathy caused by disk herniation.

DESIGN

Single-center, prospective, consecutive case series.

SETTING

A single large academic institution.

PATIENTS

A total of 11 patients with radiculopathic pain and magnetic resonance imaging findings positive for disk herniation elected to undergo single-level cervical diskectomy. METHODS OR INTERVENTIONS: Lavage was performed by needle injection and aspiration upon entering the disk space for fluoroscopic localization before diskectomy.

MAIN OUTCOME MEASUREMENTS

The lavage fluid was assayed for pH and the FAC, as well as for the cytokines interleukin-6 (IL-6), interferon-γ, monocyte chemotactic protein (MCP), and macrophage inhibitory protein-1β.

RESULTS

The subjects were 7 women and 4 men with a mean age of 50.6 years (SE 9.7; range, 36-70 years). The mean concentrations (SE; range) in picograms per milliliter were 7.9 (4.4; 0-44) for IL-6, 25.3 (15.5; 0-159) for interferon-γ, 16.1 (11.9; 0-121) for MCP, and 6.1 (2.8; 0-29) for macrophage inhibitory protein-1β. The optical density of the FAC at 450 nm was 0.151 (0.036; 0.1-0.32), and the pH was 6.68 (0.1; 6.10-7.15). Statistically significant correlations were found between MCP and FAC (P = .036) and between FAC and pH (P = .008).

CONCLUSIONS

Biochemical analysis of injured cervical intervertebral disks reveals the presence of inflammatory markers such as MCP, fragments of structural matrix proteins such as FAC, and a correlation with pH. Further evaluation of the FAC as a potential diagnostic biomarker or therapeutic target is warranted in the cervical spine.

Relationships between pathology and pain severities: a review

The relationships between pathology severity and pain severity are reviewed using the literature available for humans. The aim is to help veterinary radiologists, physicians and pathologists recognise the disorders in which severity of a lesion is likely to be related to the severity of pain or to incipient pain. Specific features or lesions within the following conditions showed a relationship with pain score, which was usually assessed with a visual analogue scale: inflammation; pancreatitis; ileitis; mucositis; fasciitis; synovitis; arthritis; lower back pain; disc herniation; sciatica; scoliosis; myalgia; cancer; arteriosclerosis; skin ulcers; mastalgia; skin and oral neuropathies; endometriosis; hepatopathy and chronic pulp diseases of the teeth. As experience with magnetic resonance imaging grows, there will be further opportunities to look for quantitative relationships in humans between pathology and pain severities. This information will be useful to veterinarians and other people working with animals in evaluating pain in animals in their care.

Cytokine evaluation in individuals with low back pain using discographic lavage

BACKGROUND CONTEXT

The pathophysiology underlying degenerative disc disease and its implication in painful syndromes remain unclear. However, spine magnetic resonance imaging (MRI) can demonstrate changes in disc water content and the annulus; provocative discography purportedly identifies degenerate discs causing serious low back pain; and biochemical assays have identified local inflammatory markers. No study to date has correlated pain on disc injection during discography evaluation with relevant MRI findings and biochemical markers.

PURPOSE

The purpose of this study was to correlate concordant pain on during discography to biochemical markers obtained by disc lavage and MRI findings.

STUDY DESIGN

This is a Phase 1 Diagnostic Test Assessment Cohort Study (Sackett and Haynes).

PATIENT SAMPLE

The patient sample included 21 symptomatic patients with suspected discogenic pain and three Phase 1 control subjects.

OUTCOME MEASURES

The outcome measures included discography pain scores, MRI degenerative grades, and immunoreactivity to various inflammatory cytokine concentrations present in disc lavage samples.

METHODS

Twenty-one symptomatic patients with lumbar degenerative disc disease and three control subjects underwent discography, MRI, and biochemical analysis of disc lavage fluid. Lumbar MRI was scored for Pfirrmann grading of the lumbar discs, and annular disruption was identified by nuclear disc lavage. Disc lavage samples were analyzed for biochemical markers by high-sensitivity immunoassay.

RESULTS

Eighty-three discs from 24 patients were studied: 67 discs from 21 patients with axial back pain (suspected discogenic pain group) and 16 discs from 3 scoliosis patients without back pain (Phase 1 control subjects). Among the biochemical markers surveyed, interferon gamma (IFN-gamma) immunoreactivity was most consistently identified in patients with axial back pain. Discs with annular disruption and concordant pain reproduction at a visual analog scale of 7 to 10/10 had greater IFN-gamma immunoreactivity than those without this finding (p=.003); however, at least some IFN-gamma immunoreactivity was found in all but one disc in the symptomatic group.

CONCLUSIONS

Among the potential inflammatory markers tested in this Phase 1 study, IFN-gamma immunoreactivity was most commonly elevated in discogram "positive" discs but absent in asymptomatic controls. However, this marker was also frequently elevated in degenerative but "negative" discography discs. From these findings, Phase 2 and Phase 3 validity studies are reasonable to pursue. Phase 4 utility studies may be performed concurrently to assess this method's predictive value in outcome studies.