Discogram Research Articles

Establishing a Gold Standard for Noninvasive Identification of Painful Lumbar Discs: Prospective Comparison of Magnetic Resonance Spectroscopy vs Low-Pressure Provocation Discography.

Verifying lumbar disc pain can present a clinical challenge. Low-pressure provocative discography (PD) has served as the gold standard, although it is invasive and often a challenge to interpret. We reported that magnetic resonance spectroscopy (MRS) biomarkers accurately predict PD results in lumbar discs and improved outcomes for patients with surgery at positive MRS levels versus nonsurgery. To further substantiate MRS for diagnosing painful discs, we report a prospective comparison of 2 MRS-derived measures: NOCISCORE (pain) and SI-SCORE (degeneration severity). Lumbar MRS and software-based postprocessing (NOCISCAN-LS, Aclarion Inc.) was performed in 44 discs in 14 patients (prospective cohort [PC]). PC data were compared to prior data used to establish the NOCISCORE (training cohort [TC]). The NOCISCORE was converted to an ordinal value (high/intermediate/low; NOCI+/mild/-) and compared against painful (P) versus nonpainful (NP) control diagnosis (PD) for 19 discs where PD was performed in the PC (12 NP; 7 P). Sensitivity, specificity, and positive and negative predictive values were calculated. The SI-SCORE was compared against MRI Pfirrmann Grades for 465 discs in 126 patients (PC plus TC). For the PC, MRS (NOCI+/-) compared to PD (P/NP) with an accuracy of 87% and sensitivity and specificity of 100%. The positive and negative predictive values of MRS were 100%. NOCISCOREs were significantly higher for PD+ versus PD- discs for PC and TC (P < 0.05), and the NOCISCORE distributions for PD+/- group were not statistically different between the PC and TC (P > 0.05). SI-SCORES differed between Pfirrmann Grades 1 and 2 (less degenerated) versus Grades 3 and 4 (more degenerated; P < 0.05), with a progressively decreasing trend with Pfirrmann Grades 1-5. These current data provide prospective confirmation of the predictive value of disc MRS for distinguishing painful discs and for assessing the disc structural integrity. NOCISCAN is an adoptable, noninvasive, and objectively quantitative test to improve management of low back pain patients.

Preclinical Animal Study and Pilot Clinical Trial of Using Enriched Peripheral Blood-Derived Mononuclear Cells for Intervertebral Disc Degeneration.

Low back pain (LBP) is a leading cause of long-term disability globally. Intervertebral disk degeneration (IVDD) is mainly responsible for discogenic pain in LBP-affected young patients. There is no effective therapy to reverse disease severity and IVDD progression. This study investigates the effect of human peripheral blood-derived mononuclear cells (PBMCs) on pain relief and life quality improvement in IVDD patients. The enriched monocytes of the PBMCs could differentiate into CD14 and CD206 double-positive M2 macrophages in vitro. Preclinical evidence in rats showed that the transplanted PBMCs exhibited anti-inflammatory and moderate tissue-repair effects on controlling IVDD progress in the rat model. The PBMCs significantly steered the aggrecan and type II collagen expressions and attenuated the pro-inflammatory cytokines in the affected disk. Based on the animal results, 36 patients with chronic low back pain (CLBP) were included in clinical trials. The control group was conservative care only, and the experimental group was platelet-rich plasma (PRP) and PBMCs intradiscal injections. We first confirmed the single lumbar disk causing the discogenic pain by provocative discography or magnetic resonance imaging (MRI). Discogenic LBP participants received one intradiscal injection of autologous PBMCs and followed for 6 months. Our clinical trial showed that patients' LBP and disability were significantly ameliorated after the PBMCs transplantation rather than PRP. These preclinical and pilot clinical studies indicate that intradiscal injection of the enriched PBMCs might be a feasible and potential cell therapy to control pain and disability in IVDD patients.

Ability of diagnostic injection to predict surgical outcomes in patients with chronic low back pain and lumbar radiculopathy

BackgroundArising from different anatomical structures of the spine, chronic low back pain is one of the leading causes of disability, and its management is still controversial. Thus, appropriate and effective management of chronic low back pain requires a precise diagnostic tool in order to target pain generators. Therefore, the role of diagnostic injection in predicting the outcome of surgical treatment of chronic low back pain and lower limb radicular pain need to be evaluated in order to guide the surgeon, especially in case of unclear pathoanatomical features. Thus, the aim of this study was to assess the predictive value of lumbar spine diagnostic injections in surgical outcome in patients with chronic low back pain and lumbar radiculopathy.Patients and methodsThis study included 30 patients complaining of chronic low back pain and/or lumbar radiculopathy who underwent lumbar spine surgery following positive diagnostic injections. The pre- and postoperative assessments consisted of a general neurological examination, evaluation of the Oswestry disability index, and a visual analog scale.ResultsThis prospective non-controlled study was conducted on 30 patients complaining of chronic low back pain and/or lumbar radiculopathy. The mean age was 42.60 ± 8.27 years with a range of 24.0–62.0 years. The visual analog scale decreased significantly from preoperative mean value of 8.26 ± 0.79 to postoperative mean value of 1.97 ± 0.92; with almost two-thirds of the patients experienced more than 75% pain reduction. The Oswestry disability index decreased significantly from preoperative mean value of 34.13 ± 4.88 to 11.47 ± 3.36 after surgery in the whole sample. The post-selective nerve root block visual analog scale was significantly correlated to the postoperative visual analog scale, while the postoperative Oswestry disability index was not significantly associated with the post-selective nerve root block visual analog scale.ConclusionThe use of lumbar selective nerve root block and lumbar provocative discography for patients with chronic low back pain and radiculopathy and equivocal radiological findings can improve surgical outcomes regarding pain intensity and spine functional outcomes. Diagnostic selective nerve root block can predict the postoperative pain relief.

Review: Discogenic Back Pain: Update on Treatment.

Lower back pain (LBP) has a lifetime prevalence of 80% in the United States population. Discogenic back pain (DBP), a subcategory of LBP, occurs as a result of the interverbal disc degeneration without disc herniation. Diagnosis relies on history, physical exam, and imaging such as MRI, provocative discography, or CT discography. Treatment of DBP involves a multifaceted approach with an emphasis on conservative measures including behavioral modification, pharmacologic management, and other non-pharmacologic interventions with invasive therapy reserved for select patients. Due to the paucity of data on the treatment of DBP, treatment also relies on data derived from treatment of chronic LBP (CLBP). Despite the scarcity of data for the treatment of DBP, treatments do exist with varying efficacy for DBP. Novel techniques such as the use of biologics may provide another avenue for treatment though further studies are needed to better evaluate the most efficacious regimen for both novel and existing treatments.

Usefulness of discography, discoblock and a new mechanical method for identifying a painful segment/disc

BackgroundWe previously described a procedure for eliciting deep spatial discrimination of individual segments in the healthy lumbar spine of normal subjects: the percutaneous mechanical provocation (PMP) test. Our goal was to devise a method for accurate identification of the spinal level of pathology in chronic low back pain (CLBP). In the present study, we validated the PMP test, using a subgroup of CLBP patients with isthmic spondylolisthesis (IS). Because there is clinical consensus that IS back pain originates in the slipped segment/disc, the level of pathology can be directly compared to the result of the PMP test. The test is agnostic with respect to the underlying pathological mechanism, and therefore might be useful in identifying the involved segment(s) irrespective of the painful structure. MethodsIn 37 patients with confirmed IS (slippage 3–15mm), we compared sensitivity between the PMP test, the widely used provocative discography test and the discoblock test. ResultsThe PMP test reliably identified the slip level in patients with IS, with sensitivity of 92%. Accepting the slipped disc as the origin of pain in IS, the sensitivity of the provocative discography and discoblock tests were 49% and 35%, respectively: i.e., too low to be contributive in clinical practice. ConclusionsThe PMP test reliably identified the origin of localized pain in IS as the slip level, but should be used with care in CLBP patients in selecting discogenic pain patients for fusion surgery, since the specificity of the test is not known and it may be positive for any origin of localized pain.

Provocative Discography: Diagnostic Efficacy and Safety in Symptomatic Degenerative Disk Disease.

This was a retrospective cohort analysis. The objective of this study was to report the efficacy and safety profile of provocative discography. It is reported that the provocative discogram as a diagnostic test for symptomatic degenerative disk disease induces disk degeneration. Discogram cases from 1998 to 2011 were identified. A matched control group with no discogram was identified. Both had pre-magnetic resonance imaging (MRI) and post-MRI with 5 years minimum between MRI studies. Statistics were generated by group for each level and for all levels combined. The discogram cohort comprised 53 patients (193 disks). The control group had 51 subjects (255 disks). There were no significant demographic differences between the groups. Time intervals between the index and follow-up MRI were 11 and 8 years for the discogram and control groups, respectively. The most common injected level was L4-L5; the most painful level was L5-S1 (Visual Analog Scale=7.9); the most concordant level was L5-S1 (75%). The most deranged level as seen on discography was L5-S1 (98%). Degeneration from normal to abnormal MRI among discogram patients was 60%. For controls, the rate was 33%. The discogram and control cohorts were statistically different (P<0.01). Among discogram patients, 58% had a fusion surgery between MRI studies. Comparing the discogram group without interval fusion to controls, the degeneration rate was not different at a 5 years' minimum follow-up. The L5-S1 intervertebral disk level was the most painful, concordant, and deranged level as seen on discogram. Patients who underwent a provocative discogram and interval fusion had a higher rate of subsequent degeneration than similar low back pain sufferers with no discogram. Degeneration rates were comparable at 5 years' minimum follow-up between discogram patients without interval spine fusion and patients without discogram exposure. The provocative discogram did not accelerate degeneration among these patients.

Degenerative Disc Diseases: A Brief Review

Back pain of different etiology is a common encountered symptoms in daily practice. Several factors were associated with the development of degenerative disease (DDD) of the intervertebral disc (IVD).&#x0D; The intervertebral disc, usually asymptomatic but once became symptomatic it will be presented as a low back pain with is consider the main complain among the patient with IVD. Both genetic as well as environmental factors lead to progressive redaction in extracellular matrix (ECM) composition which resulted overtime in weak IVD. Clinically back pain divided into two main categories: Inflammatory versus mechanical back pain, DDD typically present with mechanical type lower back pain.&#x0D; In patient with compatible history and physical exam findings, diagnosis of DDD can be confirmed by computed tomography (CT) scan, magnetic resonance imaging (MRI), or provocative discography.&#x0D; The DDD can be manage with several treatment strategies such as conservative therapy which aim to relief the pain, on the other hand, surgical approach which aim to definitely treat the DDD. The current study aims to provide a brief review about degenerative disc diseases.

Predictors of discogenic pain in magnetic resonance imaging: a retrospective study of provocative discography performed by posterolateral approach.

BackgroundProvocative discography (PD) is a test that is useful in diagnosing discogenic pain (DP). In this study, to diagnose DP, we used a posterolateral approach of needle placement and followed pressure criteria laid down by the Spine Intervention Society. The aim was to identify the correlation between magnetic resonance imaging (MRI) findings (desiccation, high intensity zone and change in shape and size of the disc) and the results of PD.MethodsRecords of 50 patients who underwent PD for DP were analyzed. A total of 109 PDs were performed, with 54 suspect and 55 control discs. Alternate pain generators were ruled out.ResultsA total of 35 suspect discs were positive on PD. The mean disc pressure in the suspect disc was 31.9 ± 7.9 psi (range, 15-44). Of the 50 patients who underwent PD, 35 had positive MRI findings. A significant positive correlation was found only between disc desiccation and discography result (r = 0.6, P < 0.001). Logistic regression analysis revealed that only desiccation successfully predicted the result of discography (OR = 26.5, P < 0.001); a high intensity zone and a disc protrusion/extrusion had an OR 2.3 and 1.24, respectively. Disc desiccation of Pfirmann grade 3 or more had a sensitivity and specificity of 0.93 and 0.64 respectively in identifying painful discs; the positive likelihood ratio was 2.58 while the negative likelihood ratio was 0.11.ConclusionsIn patients with DP, disc desiccation is the most useful MRI feature that predicts a painful disc on PD.

Intradiscal quantitative chemical exchange saturation transfer MRI signal correlates with discogenic pain in human patients

Low back pain (LBP) is often a result of a degenerative process in the intervertebral disc. The precise origin of discogenic pain is diagnosed by the invasive procedure of provocative discography (PD). Previously, we developed quantitative chemical exchange saturation transfer (qCEST) magnetic resonance imaging (MRI) to detect pH as a biomarker for discogenic pain. Based on these findings we initiated a clinical study with the goal to evaluate the correlation between qCEST values and PD results in LBP patients. Twenty five volunteers with chronic low back pain were subjected to T2-weighted (T2w) and qCEST MRI scans followed by PD. A total of 72 discs were analyzed. The average qCEST signal value of painful discs was significantly higher than non-painful discs (p = 0.012). The ratio between qCEST and normalized T2w was found to be significantly higher in painful discs compared to non-painful discs (p = 0.0022). A receiver operating characteristics (ROC) analysis indicated that qCEST/T2w ratio could be used to differentiate between painful and non-painful discs with 78% sensitivity and 81% specificity. The results of the study suggest that qCEST could be used for the diagnosis of discogenic pain, in conjunction with the commonly used T2w scan.

An Overview in the Management of Lumbar Degenerative Disc Diseases: Review Article

The degenerative disease of the intervertebral disc and back pain are chronic conditions that are caused by several factors and represent an important cause of morbidity and mortality in everyday clinical practice. The study aims to summarize the updated evidence regards epidemiology, pathophysiology, clinical manifestation, diagnosis, and management of degenerative disc diseases. The incidence of low back pain, which is the main symptom in Intervertebral Disc (IVD) disease, varies widely among different reports. It is the fifth most common cause for the visit to the doctor and affects 7.6 to 37% of patients. IVD degeneration is attributed to a complex interplay between environmental and genetic factors. DDD is a process that includes a progressive decrease in disk nutrient supply and changes in extracellular matrix (ECM) composition, which weakens the tissue strength and alters the cell metabolism.Degenerative lumb disc disease patients typically present with mechanical lower back pain, which is worse on forward flexion and when carrying heavy load. The pain is relieved with rest. Diagnosis of DDD is done by various methods, computed tomography (CT) scan, magnetic resonance imaging (MRI), and provocative discography. These methods should be used in conjunction with the patient history, physical examination and specific biomarker to monitor the response to treatment. There are three major lines of management of DDD; Treatment Options for Relief of Pain in Conservative Therapy.Treatment with Aims of Restoration, Repair, and Regeneration of Intervertebral Disc Diseases: Molecular Therapy. Reconstructive Strategies: Percutaneous Intervertebral Disc Techniques. Definitive Treatment for Intervertebral Disc Diseases :( surgical management).

Intradiscal Platelet-Rich Plasma Injection for Discogenic Low Back Pain and Correlation with Platelet Concentration: A Prospective Clinical Trial

Discogenic pain is common cause of low back ache and may result in significant morbidity. Platelet-rich plasma (PRP) is an upcoming regenerative therapy that has treatment potential for this condition. The objective of this study was to correlate platelet concentration in intradiscal PRP injection with improvement in low back pain and functional status at three and six months. Prospective single-arm interventional study. Outpatient pain clinic and operation theater. Twenty-five patients with discogenic pain diagnosed by clinical means and imaging with confirmation by provocative discography were recruited. The patients received PRP injection at a single or multiple disc levels. Preprocedure numerical rating scale (NRS) pain scores and Oswestry Disability Index (ODI) scores were calculated. Platelet counts of patients and PRP samples were measured. At three and six months postprocedure, NRS and ODI scores were measured, and improvement in these scores was correlated with platelet concentrations in the PRP sample. Twenty patients completed the study. The improvement in NRS and ODI scores positively correlated with platelet concentrations in the PRP sample. We determined the correlation coefficient (r) of platelet concentrations with a reduction in NRS at three months (r = 0.65) and six months (r = 0.73) and in ODI score at three months (r = 0.72) and six months (r = 0.7). This study supports the use of intradiscal PRP for treatment of discogenic pain with preferably higher platelet counts to elicit a favorable response.

Prevalence and Discordance of the "Startle Response" with True Discogenic Pain According to Spine Intervention Society Guidelines for Provocation Discography: A Cohort Study.

The literature on cervical provocation discography (C-PD) is sparse. A "Startle Response" during C-PD is a known phenomenon that might be mistaken as an indicator of discogenic pain at the provoked disc level, but this has not been quantitatively described. To determine the incidence of the Startle Response and its concordance/discordance with true-positive C-PD in patients referred for surgical planning or evaluation after ruling out other axial pain generators. Retrospective cohort study of consecutive patients who received C-PD at an outpatient spine center. The primary outcome was the rate of discordance of the Startle Response with true-positive C-PD according to the operational criteria of the Spine Intervention Society (SIS) guidelines. One hundred five discs were provoked in 36 individuals (19 female, mean age [SD] = 45.7 [10.9] years). C-PD was performed at a median of three levels (range = 1-5) with C4/5 (N = 30), C5/6 (N = 30), and C6/7 (N = 31) the most commonly evaluated. Twenty-six of 36 patients reported responses consistent with true-positive C-PD. A Startle Response was observed in 14 patients (39%, 95% confidence interval [CI] = 23-57%), and 22 of 105 (21%, 95% CI = 14-30%) provoked discs. Of the 14 patients who exhibited a Startle Response, four had negative C-PD results (29%, 95% CI = 8-58%). As assessed per disc, C-PD results were positive in 12 of the 22 (55%, 95% CI = 32-76%) provoked discs that generated a Startle Response. The present data demonstrate high discordance, 45% (95% CI = 24-68%), between the Startle Response and true-positive C-PD. Clinicians should be aware of this phenomenon and take care to distinguish it from a true-positive response during C-PD, as defined by the SIS guidelines. Misinterpretation of the Startle Response as a positive C-PD result may lead to inappropriate future care decisions in a substantial proportion of patients.

The Association Between Magnetic Resonance Imaging Disc Pathology and Provocative Discography at the Lumbar Level.

The objective of this study was to show that degenerative lumbar magnetic resonance imaging findings variably increase discography pain by level. Lumbar discography and magnetic resonance imaging of 736 patients were retrospectively reviewed. Univariate/multivariate logistic regressions calculated the odds ratio (OR) (95% confidence interval, P < 0.05). L3-4 multivariate regression OR for a degenerative disc is 9.9; for bulge, 10.9; for annular tear, 38.9; for herniation, 51.5; and for degenerative facet, 2.158. Endplate changes were not significant. L4-5 OR for a degenerative disc is 4.52; for bulge, 13.74, for tear, 19.13; for herniation, 28.65; for endplate edema, 3.47; and fatty change, 3.84. Degenerative facet ORs were not significant. L5-S1 OR for a degenerative disc is 6.86; for bulge, 5.65; for tear, 40.56; and for herniation, 77.98. Endplate changes and degenerative facet OR's were not significant. Advancing degeneration increases pain at L5-S1 followed by L3-4. Endplate signal is significant only at L4-5.

Provocative Discography Following Focal Selective Coagulation in a Patient with Chronic Lumbar Discogenic Pain

Provocative Discography Following Focal Selective Coagulation in a Patient with Chronic Lumbar Discogenic Pain

Amniotic Umbilical Cord Particulate for Discogenic Pain.

Discogenic low back pain is the most common type of low back pain and is a major cause of morbidity worldwide. Current nonoperative treatment options are limited in efficacy and lack evidence of long-term pain relief; thus, there is an unmet clinical need for an effective treatment for patients with discogenic pain. Amniotic membrane and umbilical cord (AMUC) particulate may be useful in relieving pain and inhibiting the degenerative cascade in patients with discogenic pain by reducing inflammation. To evaluate the effectiveness of AMUC particulate for discogenic pain. Six months of conservative therapy failed in patients who had discogenic pain confirmed by magnetic resonance imaging and provocative discography. They subsequently received intradiskal injection of 50 to 100 mg of AMUC particulate for cervical, lumbar, and lumbosacral disks. A total of 11 patients with 20 disks were included. Before treatment, all patients reported severe pain, and 10 patients took opioids daily. After treatment, the median reported pain relief was 40%, 50%, and 75% at 1-month (n=6), 3 months (n=8), and 6 months (n=5), respectively. Complete pain relief was noted in 1 patient; however, 2 patients (18%) reported no pain relief at 1 and 3 months. No adverse events, repeated procedures, or complications occurred. This preliminary evidence suggests that a single intradiskal injection of AMUC particulate is safe and may provide symptomatic pain relief in some patients with discogenic pain.

Low-Pressure Lumbar Provocation Discography According to Spine Intervention Society/International Association for the Study of Pain Standards Does Not Cause Acceleration of Disc Degeneration in Patients With Symptomatic Low Back Pain: A 7-Year Matched Cohort Study.

Retrospective matched cohort study. To determine if low-pressure lumbar provocation discography (PD) results in long-term accelerated disc degeneration, internal disc disruption, or disc herniation in patients with symptomatic low back pain (LBP). Study of subjects without clinically-significant LBP suggests that high-pressure PD may accelerate disc degeneration. Consecutive patients with symptomatic LBP who underwent magnetic resonance imaging (MRI), PD, and repeat MRI more than 7 years later, but did not undergo subsequent spinal fusion surgery, were included. Punctured discs were matched (1:2 to 1:4) to corresponding discs in a control cohort by age, BMI, Pfirrmann score (±2), and presence of disc herniation; control cohort inclusion required MRIs for symptomatic LBP, separated by more than 7 years. The primary outcome of the study was a progression in Pfirrmann score category (I-II, III-IV, V). MRI disc-to-CSF T2 signal-intensity ratio, disc height, disc herniations, high intensity zones (HIZs), and Modic changes were assessed. Baseline and follow-up MRIs were available for 77 discs exposed to PD, and for 260 discs in the matched control cohort. There was no difference in the proportion of punctured discs that advanced in Pfirrmann score category in the PD group (17%, 95% CI 9-27%) compared with corresponding discs in the Control group (21%, 95% CI 17-27%), P = 0.3578, or in non-punctured discs in the PD group (35%, 95% CI 21-51%) compared with corresponding discs in the Control group (34%, 95% CI 27-42%), P = 0.1169. There were no differences in disc-to-CSF T2 signal-intensity ratio, presence of disc herniations, HIZs, or Modic changes following puncture in the PD versus matched cohort discs or in the non-punctured PD cohort discs versus corresponding control cohort discs (P > 0.05). Patients with symptomatic LBP who underwent low-pressure PD, but who did not undergo a subsequent spinal fusion surgery, developed disc degeneration and new disc herniations at a similar rate to corresponding discs in matched control patients. 3.

Positive Predictive Values of Lumbar Spine Magnetic Resonance Imaging Findings for Provocative Discography

The purpose of this study was to calculate the positive predictive value (PPV) of lumbar spine magnetic resonance imaging (MRI) findings for a painful disc using provocative discography. Lumbar spine discography records and prediscography MRIs of 736 patients (2457 discs) who underwent discography for diagnostic purposes from 2003 to 2007 were retrospectively reviewed in an Institutional Review Board-exempt and Health Insurance Portability and Accountability Act-compliant protocol. Each level was identified as having high-intensity zone (HIZ) disc, disc protrusion, disc extrusion, or combination (any herniation type), disc bulge, disc degeneration, and spondylolisthesis. Statistical analysis used a 2 × 2 contingency table of significant discography results for each of the MRI variables to calculate P value and PPV with a confidence interval from a binomial distribution. An HIZ disc has a PPV of 0.71 (0.65-0.76, P = 4.31E - 44) for a provocative discography. A disc protrusion has a PPV of 0.79 (0.73-0.83, P = 2.68E - 53). A disc extrusion has a PPV of 0.93 (0.79-0.98, P = 1.34E - 14), a bulge of 0.43 (0.37-0.48, P = 0.002), and a degenerative disc of 0.32 (0.28-0.35, P = 0.08), and spondylolisthesis has a PPV of 0.67 (0.59-0.73, P = 1.70E - 20). A herniation of either type (extrusion or protrusion) has a PPV of 0.80 (0.75-0.84, P = 5.86E - 69). Disc herniations and HIZ discs have high predictive value in identifying a pain generator. An extruded disc herniation has the highest PPV for discogenic pain.

Using Percutaneous Endoscopic Outside-In Technique to Treat Selected Patients with Refractory Discogenic Low Back Pain

Background: Controversy is not uncommon in the diagnosis of discogenic low back pain (DLBP) and in the identification of the location of the pain source for the symptomatic disc in patients with DLBP. Various techniques, from minimally invasive procedures to fusion surgery, are used to treat chronic DLBP, but the clinical outcomes are variable. Percutaneous endoscopic discectomy by transforaminal or interlaminar approach is considered to be an effective method to treat DLBP, but the evidence is limited; the lack of clear evidence may be associated with patient selection and surgical technique. Objectives: The purpose of this study is to evaluate the clinical results of percutaneous endoscopic treatment for annular tear in selected patients with DLBP by using the outside-in technique. Study Design: A prospective study and retrospective observations were performed on 24 consecutive patients with a minimum 2 years of follow-up. This study was approved by the Institutional Review Board (IRB) of Buddhist Dalin Tzu-Chi General Hospital Foundation (IRB number: 10504004) and written informed consent was obtained from all patients. Setting: This research took place within an interventional pain management and spine practice. Methods: Twenty-four consecutive patients with single-level DLBP diagnosed by positive highintensity zone on magnetic resonance imaging, positive provocative discography, and block test underwent a percutaneous endoscopic procedure from January 2014 to December 2015. The transforaminal approach or interlaminar approach was selected according to the location of the annular tear. The torn lesions were visualized directly and treated by puncture and debridement of the inflammatory tissues from the outer annulus fibrosus to the inner nucleus using the outsidein technique. The Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI) score were evaluated before and after surgery. The clinical global outcomes were assessed on the basis of modified MacNab criteria. Results: These patients included 13 men and 11 women with a mean age of 43.8 years (range, 32-55 yrs). There were 15 lesion levels at L4/L5 and 9 lesion levels at L5/S1. Among them, 15 levels were accessed by transforaminal approach and 9 levels by interlaminar approach. No serious complications were observed during the follow-up periods. All except 2 patients experienced significant symptomatic and functional improvements at the 2-year follow-up with a success rate of 91.7%. Limitations: Significant limitations include nonrandom format and small sample size. Future research may focus on controlled prospective studies with larger sample sizes and long-term followup to examine the validity of this protocol. Conclusions: The percutaneous endoscopic procedure provides a safe and effective treatment for selected patients with DLBP. The outside-in technique allows the surgeons to visualize and treat the torn or inflammatory lesions directly, and the success rate is high at 2 years follow-up. Key words: Transforaminal, interlaminar, outside-in technique, endoscopic discectomy, discogenic low back pain

Magnetic resonance spectroscopy (MRS) can identify painful lumbar discs and may facilitate improved clinical outcomes of lumbar surgeries for discogenic pain

PurposeThe goal of this study was to refine clinical MRS to optimize performance and then determine whether MRS-derived biomarkers reliably identify painful discs, quantify degeneration severity, and forecast surgical outcomes for chronic low back pain (CLBP) patients.MethodsWe performed an observational diagnostic development and accuracy study. Six hundred and twenty-three (623) discs in 139 patients were scanned using MRS, with 275 discs also receiving provocative discography (PD). MRS data were used to quantify spectral features related to disc structure (collagen and proteoglycan) and acidity (lactate, alanine, propionate). Ratios of acidity to structure were used to calculate pain potential. MRS-SCOREs were compared to PD and Pfirrmann grade. Clinical utility was judged by evaluating surgical success for 75 of the subjects who underwent lumbar surgery.ResultsTwo hundred and six (206) discs had both a successful MRS and independent pain diagnosis. When comparing to PD, MRS had a total accuracy of 85%, sensitivity of 82%, and specificity of 88%. These increased to 93%, 91%, and 93% respectively, in non-herniated discs. The MRS structure measures differed significantly between Pfirrmann grades, except grade I versus grade II. When all MRS positive discs were treated, surgical success was 97% versus 57% when the treated level was MRS negative, or 54% when the non-treated adjacent level was MRS positive.ConclusionMRS correlates with PD and may support improved surgical outcomes for CLBP patients. Noninvasive MRS is a potentially valuable approach to clarifying pain mechanisms and designing CLBP therapies that are customized to the patient.Graphical abstractThese slides can be retrieved under Electronic Supplementary Material.

The relevance of high-intensity zones in degenerative disc disease.

The purpose of this study was to review the current understanding of high-intensity zones (HIZ) in the lumbar spine with particular attention to its imaging phenotype and clinical relevance. A review was conducted of studies related to HIZ. Particular attention was made to imaging phenotypes and classification, and its relationship with discogenic low back pain (LBP). The most current classification system of HIZ is based on location (anterior and posterior), morphology (round, fissure, vertical, rim, or giant types), and its appearance on both T1- and T2-weighted magnetic resonance imaging (MRI). HIZ are commonly manifested with disc degeneration. Hence, both conditions share similar risk factors such as the effect of frequent and prolonged disc loading. The clinical significance of HIZ however is not conclusive. Provocative discography is not sensitive (~ 70%) for eliciting a concordant pain response. Population-based studies have conflicting results regarding the prevalence (14-63%) of HIZ and its correlation with LBP. HIZ are likely a risk factor for discogenic LBP. However, its etiology and pathophysiology are not well understood. Some clinical studies suggest a link between its occurrence and LBP. However, the results are not consistent as a result of studies which are underpowered and based on heterogeneous study populations, lacking control groups, and without standardized imaging phenotypes. HIZ may be an important pain biomarker that should be further studied. With more modern MRI technology and a detailed classification system, future large-scale population studies will improve our knowledge on its role in the disc degeneration cascade and development of LBP.