Pathomechanisms of sciatica in lumbar disc herniation: effect of periradicular adhesive tissue on electrophysiological values by an intraoperative straight leg raising test

Straight leg raise versus knee extension angle: which structure limits the test in asymptomatic subjects?

OBJECTIVES

This study aimed to determine if the first onset of symptoms (discomfort) during the straight leg raise (SLR) (hip flexion with an extended knee) and the Knee Extension Angle (KEA) tests (knee extension with 90°of hip flexion) results from nervous or muscular structures in asymptomatic individuals. The secondary objective was to investigate if the gender influences the structure related to the discomfort.

METHODS

This cross-sectional study consisted of a single assessment session during which the structure related to participants' discomfort during the KEA and SLR was identified. For this identification, a structural differentiation (SD) was conducted during both tests using passive mobilization of the cervicothoracic spine in flexion and extension. Changes in participants' discomfort were monitored during the SD to determine whether a change or lack of change was consistent with variations in the load applied to the suspected structures either muscular or neural. If the structure related to the participants' discomfort could not be identified, two additional tests were conducted: the lateral SLR and the Slump test.

RESULTS

One hundred and seventy-eight individuals were included. Median [IQR] age was 21 years [20;23], and 57.3% were female. The structure related to participants' discomfort was similar for the SLR and the KEA (p = 0.451): neural for 72.5% of participants in the SLR and 75.8% in the KEA. Gender only influenced the structure identified in the KEA test, with a significantly higher rate of nerve-related discomfort in females than males and a significantly higher rate of muscle-related discomfort in males (p = 0.002).

CONCLUSION

In asymptomatic individuals, the discomfort induced by the SLR and the KEA tests could be related to either muscular or neural structures. Therefore, structural differentiation is necessary to identify the structure causing the discomfort in both research and clinical practice.

Risk Factors Involved in the Early and Medium-Term Poor Outcomes of Percutaneous Endoscopic Transforaminal Discectomy: A Single-Center Experience

Objective

To investigate the risk factors involved in the early and medium-term poor outcomes of percutaneous endoscopic transforaminal discectomy (PETD) treatment of lumbar disc herniation (LDH) at the L4-5 level.

Methods

Between January 2015 and May 2020, we recruited 148 LDH patients at the L4-5 level who underwent PETD surgery. The patients were divided into Groups A and B, according to the surgical outcomes. Good and excellent outcomes were categorized into Group A, and generally good and poor outcomes were categorized into Group B. Clinical parameters (age, gender, symptom duration, hospital stay, operation time, blood loss, straight-leg raising (SLR), visual analog scale (VAS), Oswestry Disability Index (ODI) score and modified MacNab criteria) and radiologic parameters (foraminal height (FH), intervertebral height index (IHI), intervertebral angle (IVA), sagittal range of motion (sROM), and lumbar lordosis (LL)) were collected and analyzed using univariate and multiple logistic regression analyses.

Results

At the 6-month follow-up post operation, univariate analysis revealed that the symptom duration, SLR, IHI, and sROM were strongly associated with poor outcomes. However, multiple logistic regression analysis demonstrated that prolonged symptom duration, large SLR angel, and large sROM were independent risk factors for poor outcomes. At the 2-year follow-up post operation, univariate analysis suggested that advanced age, prolonged symptom duration, large preoperative VAS score, small FH, small IHI, and large sROM were potential risk factors for poor outcomes. However, multiple logistic regression analysis demonstrated that prolonged symptom duration, small IHI, and large sROM were independent risk factors for poor outcomes.

Conclusion

Our study demonstrated that prolonged symptom duration, large SLR angel, and large sROM were independent risk factors for poor outcomes immediately following PETD at the L4-5 level. However, prolonged symptom duration, small IHI, and large sROM were independent risk factors for poor outcomes at medium-term post PETD at the L4-5 level.

Six Revision Surgeries for Massive Epidural Fibrosis with Recurrent Pain and Weakness in the Left Lower Extremity

Epidural fibrosis is a common cause of pain after lumbar surgeries. There are no previous reports documenting profound limb weakness associated with epidural fibrosis. A 43-year-old woman uneventfully underwent microscopic discectomy. However, six additional surgeries were needed due to recurrent pain and weakness episodes, several days after the surgery. Operative findings were severe epidural fibrosis around the thecal sac and nerve roots. Epidural fibrosis excision did not prevent recurrent fibrosis; therefore, we performed a lordotic fusion with posterior column shortening to reduce neural tension and nerve-root stretching. Eventually, she became free from recurrent episodes of deteriorations and repetitive surgeries.

Novel Transdural Epiarachnoid Approach for Large Central Disk Herniation in Upper Lumbar Spine

BACKGROUND AND IMPORTANCE

The treatment for large central disk herniation (LCDH) at upper lumbar spine is often challenging. Previous reports showed various surgical strategies, such as microdiscectomy with posterior fixation, endoscopic surgery, and microdiscectomy through transdural approach. However, there is no consensus regarding which surgical option is better for LCDH at upper lumbar spine. In this report, we describe the novel transdural epiarachnoid approach (TDEA), which uses the corridor of epiarachnoid space for microdiscectomy. Compared with classical transdural approaches, this novel approach may reduce risks of postoperative cerebrospinal fluid leakage and the development of arachnoiditis.

CLINICAL PRESENTATION

A 69-yr-old man presented with progressive bilateral radiating leg pain, intermittent claudication, and low back pain. Magnetic resonance images and computed tomography scans revealed LCDH at L2/3 level. We performed microdiscectomy using the TDEA. Postoperative course was uneventful, and his symptoms were relieved after surgery.

CONCLUSION

The novel TDEA for LCDH at upper lumbar spine is illustrated with a video. This novel approach has an advantage of the preservation of subarachnoid components compared with classical transdural approaches.

Comparing the Effects of Early Versus Late Exercise Intervention on Pain and Neurodynamic Mobility Following Unilateral Lumbar Microdiscectomy: A Pilot Study

STUDY DESIGN

A pilot, two-group pretest-posttest randomized controlled, single blinded study.

OBJECTIVE

Our study aim was to compare the changes in low back pain level, fear avoidance, neurodynamic mobility, and function after early versus later exercise intervention following a unilateral lumbar microdiscectomy.

SUMMARY OF BACKGROUND DATA

Exercise is commonly recommended to patients following a lumbar microdiscectomy although controversy remains as to the timing and protocols for exercise intervention.

METHODS

Forty patients were randomly allocated to early (Group 1) or later (Group 2) exercise intervention group. The low back pain and fear avoidance were evaluated using Oswestry Low Back Pain Disability Questionnaire, Numeric Pain Rating Scale, and Fear-Avoidance Beliefs Questionnaire. The neurodynamic mobility and function were recorded with Dualer Pro IQ Inclinometer, 50-foot walk test, and Patient-Specific Functional Scale. Two-sided t test for continuous variables and chi-square or Fisher exact test for categorical variables were used to compare the two groups' demographic data. The Wilcoxon signed-rank and rank-sum tests were used to compare the changes and the differences, respectively, in low back pain, fear avoidance, neurodynamic mobility, and function between baseline (before surgery) and postoperative repeated measurements (at 1-2, 4-6, and 8-10 wks after surgery) within each study group, after exercise intervention.

RESULTS

Both groups showed a significant decrease in low back pain levels and fear avoidance as well as a significant improvement in neurodynamic mobility and function at 4 and 8 weeks after surgery. However, no significant difference was reported between the two groups.

CONCLUSION

Our study results showed that early exercise intervention after lumbar microdiscectomy is safe and may reduce the low back pain, decrease fear avoidance, and improve neurodynamic mobility and function. A randomized controlled trial is needed to evaluate the early exercise intervention's effectiveness after lumbar microdiscectomy, and thus validate our findings.Level of Evidence: 4.

Is Endoscopic Discectomy the Next Gold Standard in the Management of Lumbar Disc Disease? Systematic Review and Superiority Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

We performed this meta-analysis to evaluate whether endoscopic discectomy (ED) shows superiority compared with the current gold standard of microdiscectomy (MD) in management of lumbar disc disease.

MATERIALS AND METHODS

We conducted independent and duplicate electronic database search including PubMed, Embase, and Cochrane Library from 1990 till April 2020 for studies comparing ED and MD in the management of lumbar disc disease. Analysis was performed in R platform using OpenMeta[Analyst] software.

RESULTS

We included 27 studies, including 11 randomized controlled trials (RCTs), 7 nonrandomized prospective, and 9 retrospective studies involving 4018 patients in the meta-analysis. We stratified the results based on the study design. Considering the heterogeneity in some results between study designs, we weighed our conclusion essentially based on results of RCTs. On analyzing the RCTs, superiority was established at 95% confidence interval for ED compared with MD in terms of functional outcomes like Oswestry Disability Index (ODI) score (P = .008), duration of surgery (P = .023), and length of hospital stay (P < .001) although significant heterogeneity was noted. Similarly, noninferiority to MD was established by ED in other outcomes like visual analogue scale score for back pain (P = .860) and leg pain (P = .495), MacNab classification (P = .097), recurrences (P = .993), reoperations (P = .740), and return-to-work period (P = .748).

CONCLUSION

Our meta-analysis established the superiority of endoscopic discectomy in outcome measures like ODI score, duration of surgery, overall complications, length of hospital stay and noninferiority in other measures analyzed. With recent advances in the field of ED, the procedure has the potential to take over the place of MD as the gold standard of care in management of lumbar disc disease.

Extending the straight leg raise test for improved clinical evaluation of sciatica: reliability of hip internal rotation or ankle dorsiflexion

Background

The straight leg raise (SLR) is the most commonly applied physical tests on patients with sciatica, but the sensitivity and specificity ratings for disc hernia and neural compression leave areas for improvement. Hip internal rotation tensions the lumbosacral nerve roots and ankle dorsiflexion tensions the sciatic nerve along its course. We added these movements to the SLR (extended SLR = ESLR) as structural differentiators and tested inter-rater reliability in patients with LBP, with and without sciatica.

Methods

Forty subjects were recruited to the study by the study controller (SC), 20 in the sciatic group and in the control group. Two independent examiners (E1&E2) performed the ESLR and did not communicate to the subjects other than needed to determine the outcome of the ESLR. First, SLR was performed traditionally until first responses were evoked. At this hip flexion angle, a location-specific structural differentiation was performed to confirm whether the emerged responses were of neural origin. Cohen’s Kappa score (CK) for interrater reliability was calculated for ESLR result in detection of sciatic patients. Also, the examiners’ ESLR results were compared to the traditional SLR results.

Results

The interrater agreement between Examiner 1 and Examiner 2 for the ESLR was 0.85 (p < 0.001, 95%CI: 0.71–0.99) translating to almost perfect agreement as measured by Cohen’s Kappa When the ESLR was compared to the traditional SLR, the overall agreement rate was 75% (30/40). Kappa values between the traditional SLR and the E1’s or E2’s ESLR results were 0.50 (p < 0.0001; 95%CI 0.27–0.73) and 0.54 (p < 0.0001; 95%CI 0.30–0.77), respectively.

Conclusions

ESLR with the addition of location-specific structural differentiation is a reliable and repeatable tool in discerning neural symptoms from musculoskeletal in patients with radiating low back pain. We recommend adding these movements to the standard SLR with aim of improving diagnostic ability.

Percutaneous Discectomy Followed by CESI Might Improve Neurological Disorder of Drop Foot Patients Due to Chronic LDH

(1) Introduction: Epiconus and conus medullary syndromes that consisted of drop foot, pain, numbness, bladder or bowel dysfunction are serious problems might be caused by lumbar disc(s) herniation (LDH) compression. (2) Objective: To evaluate percutaneous discectomy effectivity for decompressing LDH lesions. (3) Case Report: Three patients suffered from drop feet, numbness, and bowel and bladder problems due to LDH compression. Patient #1 is a male (35 years old, basal metabolism index (BMI) = 23.9), point 1 on manual muscle test (MMT), with protrusion on L3 to S1 discs; Patient #2 is a female (62 years old, BMI = 22.4), point 3 on MMT, with protrusion on L2-4 and L5-S1 discs; Patient #3 is a female (43 years old, BMI = 26.6), point 4 on MMT, with extrusion on T12-L1 and L1-2 and L3-4 protruded discs. Six months follow-up showed of stand and walkability improvement with Patient #1 and #2. Patient #3 showed improvement in bowel and bladder problems within 10 weeks, without suffering of postoperative pain syndromes. (4) Discussion: Patient #1 and #2 showed better outcomes than Patient #3 who affected epiconus and cauda equina syndromes. Triamcinolone and lidocaine have analgesic and anti-inflammatory properties for improving intraepidural circulation adjacent to the lesion sites. (5) Conclusion: Drop foot caused by mechanical compression of LDH ought to be treated immediately. Lateral or posterolateral compression has better outcomes associated with anatomical structures. Discectomy through transforaminal approach that is followed by caudal epidural steroid injection (CESI) under fluoroscopic guidance is a safer and minimally invasive treatment with promising outcomes.

Normalization of Spinal Cord Displacement With the Straight Leg Raise and Resolution of Sciatica in Patients With Lumbar Intervertebral Disc Herniation: A 1.5-year Follow-up Study

STUDY DESIGN

A controlled radiologic follow-up study.

OBJECTIVE

The aim of this study was to ascertain whether changes in cord excursion with straight leg raise test (SLR) at 1.5-year follow-up time accompany changes in clinical symptoms.

SUMMARY OF BACKGROUND DATA

Lumbar intervertebral disc herniation (LIDH) is known to be a key cause of sciatica. Previously, we found that a significant limitation of neural displacement (66.6%) was evident with the SLR on the symptomatic side of patients with subacute single level posterolateral LIDH.

METHODS

Fourteen patients with significant sciatic symptoms due to a subacute single-level posterolateral LIDH were reassessed clinically and radiologically at 1.5 years follow-up with a 1.5T MRI scanner. Displacement of the conus medullaris during the unilateral and bilateral SLR was quantified reliably with a randomized procedure and compared between SLRs and to data from baseline. Multivariate regression models and backward variable selection method were employed to identify variables more strongly associated with a decrease in low back pain (LBP) and radicular symptoms.

RESULTS

Compared with previously presented baseline values, the data showed a significant increase in neural sliding in all the quantified maneuvers (P ≤ 0.01), and particularly of 2.52 mm (P ≤ 0.001) with the symptomatic SLR.Increase in neural sliding correlated significantly with decrease of both radicular symptoms (Pearson = -0.719, P ≤ 0.001) and LBP (Pearson = -0.693, P ≤ 0.001). Multivariate regression models and backward variable selection method confirmed the improvement of neural sliding effects (P ≤ 0.004) as the main variable being associated with improvement of self-reported clinical symptoms.

CONCLUSION

To our knowledge, these are the first noninvasive data to objectively support the association between increase in magnitude of neural adaptive movement and resolution of both radicular and LBP symptoms in in vivo and structurally intact human subjects.

LEVEL OF EVIDENCE

2.

A review of the role of epidural percutaneous neuroplasty

Degeneration, whether from age or postsurgical, in the ventral and lateral epidural space can lead to irritation of both the nerve roots and of the nerves present in the epidural space, the peridural membrane and the posterior longitudinal ligament. This irritation is often accompanied by mild scarring. Neuroplasty is a specific procedure designed to relieve this irritation. The effectiveness of neuroplasty is not affected by the extent of spinal stenosis. Neuroplasty can be performed in the lumbar, thoracic and cervical spine, and using caudal, transforaminal and interlaminar approaches. Postprocedural home exercises are an integral part of the procedure. There are multiple high-grade studies positive for the effectiveness and safety of neuroplasty. Neuroplasty should be offered prior to surgery in patients with persistent back and/or extremity pain.

Which clinical and radiological variables could predict clinical outcomes of percutaneous endoscopic lumbar discectomy for treatment of patients with lumbosacral disc herniation?

BACKGROUND CONTEXT

Percutaneous endoscopic lumbar discectomy (PELD) is one of minimally invasive techniques to treat patients with low back and radiating pain resulting from lumbosacral disc herniation (LDH).

PURPOSE

The purpose of this study is to evaluate the clinical efficacy of PELD to treat patients with low back and radicular pain due to LDH and to investigate which clinical and radiological variables have the ability to predict clinical outcome after PELD.

STUDY DESIGN/SETTING

This is a retrospective study design carried out at a spine hospital.

PATIENT SAMPLE

The sample comprised 75 patients who had undergone PELD for treatment of low back and radiating leg pain resulting from LDH and who could be followed up for at least 12 months.

OUTCOMES MEASURES

Clinical outcomes were assessed using numeric rating scale for back and radiating leg pain (NRS back and leg), Oswestry Disability Index (ODI), and modified MacNab criteria at 1 month (short-term follow-up) and at least 12 months (long-term follow-up) after PELD.

METHODS

The patients were divided into successful and unsuccessful outcome groups according to improvement of NRS back, NRS leg, and ODI (%) at long-term follow-up period. We compared the various clinical and radiological variables between the two groups to identify which variables could be the prognostic factors of clinical outcomes of PELD. This analysis was performed in terms of whole population, the subgroup of dominant back pain, and the subgroup of dominant leg pain, respectively.

RESULTS

Significant improvements were observed in NRS back, NRS leg, ODI (%), and modified MacNab criteria at short-term and long-term follow-up after PELD. Positive straight leg raising (SLR) was significantly related to successful outcome as to NRS leg and ODI (%), and longer pain duration also showed significant relationship with unsuccessful outcomes as to NRS leg in whole population. Positive SLR had significant relationship with successful NRS leg as well as successful ODI (%) in the subgroup of dominant leg pain.

CONCLUSIONS

PELD was an effective treatment in patients with back and leg pain due to LDH. Positive SLR had the predictive ability to successful reduction of radiating leg pain and successful functional improvement. Longer pain duration was also related to unsuccessful reduction of radiating leg pain.

Lumbar Disc Herniation

PURPOSE OF REVIEW

Substantial advancements have been made in the cause, diagnosis, imaging, and treatment options available for patients with lumbar disc herniation (LDH). We examined the current evidence and highlight the concepts on the frontline of discovery in LDH.

RECENT FINDINGS

There are a myriad of novel etiologies of LDH detailed in recent literature including inflammatory factors and infectious microbes. In the clinical setting, recent data focuses on improvements in computer tomography as a diagnostic tool and non-traditional injection options including tumor necrosis alpha inhibitors and platelet-rich plasma. Operative treatment outcomes have focused on minimally invasive endoscopic approaches and demonstrated robust 5-year post-operative outcomes. Advances in the molecular etiology of LDH will continue to drive novel treatment options. The role of endoscopic treatment for LDH will continue to evolve. Further research into10-year outcomes will be necessary as this surgical approach continues to gain widespread popularity.

Reduced Spinal Cord Movement With the Straight Leg Raise Test in Patients With Lumbar Intervertebral Disc Herniation

STUDY DESIGN

Controlled radiological study.

OBJECTIVE

To explore whether impairment of neural excursion during the straight leg raise test occurs in patients with sciatic symptoms secondary to lumbar intervertebral disc herniation (LIDH).

SUMMARY OF BACKGROUND DATA

Earlier studies have shown that during the straight leg raise (SLR) test in asymptomatic volunteers tensile forces are consistently transmitted throughout the neural system and the thoracolumbar spinal cord slides distally.

METHODS

Fifteen patients with sciatic symptoms due to subacute LIDH were studied with a 1.5 T magnetic resonance scanner. First, a spine specialist diagnosed the LIDH using conventional scanning sequences. Following this subjects were scanned using different scanning sequences for planning and measurement purposes. Displacement of the conus medullaris during the unilateral and bilateral SLR was quantified reliably with a randomized procedure and compared between manoeuvres.

RESULTS

The results showed 66.6% less excursion of conus medullaris with SLR performed on the symptomatic side compared with excursions measured with SLR performed on the asymptomatic side (p ≤ 0.001).

CONCLUSION

In patients with LIDH, the neural displacement on the symptomatic side is significantly reduced by the compressing IVD herniation. To our knowledge, these are the first data in intact human subjects to support the limitation of neural movements in the vertebral canal with LIDH.

LEVEL OF EVIDENCE

3.

Normal multiplanar movement of the spinal cord during unilateral and bilateral straight leg raise: Quantification, mechanisms, and overview

The purpose of this investigation was to provide a full set of normal data describing neural biomechanics within the vertebral canal in all three planes with unilateral and bilateral SLR tests to allow for clinical comparison with clinical cases. This is done following the notion that, due to neural continuum, tensile forces are transmitted through the lumbosacral nerve roots and dura to the conus medullaris (linear dependency principle). In this controlled radiologic study 10 asymptomatic volunteers were scanned with 1.5T magnetic resonance scanner (Siemens Magnetom Aera, Erlangen, Germany) using different scanning sequences for planning and for measurement purposes. Conus displacement in both antero-posterior direction (sagittal slices) and lateral direction (axial slices) was quantified during unilateral passive left, right SLR, and bilateral SLR and compared with the position of the conus in the neutral (anatomic) position. It is shown that the conus medullaris displaced laterally and anteroposteriorly in response to unilateral and bilateral SLRs. Pearson's correlations were higher than 0.95 for both intra- and inter-observer reliability. The observed power was higher than 0.99 for all the variables tested. Following this, the authors conclude that lateral and antero-posterior displacement of conus medullaris into the vertebral canal occurs consistently with unilateral and bilateral SLRs following directions predicted by tension vectors. Summative information collected in this line of research in neuroradiology is here presented. We believe we have presented the first conclusive and complete full set of normal data on non-invasive, in vivo, normative measurement of spinal cord displacement with the SLR ever presented. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1335-1342, 2017.

In Vivo MRI Measurement of Spinal Cord Displacement in the Thoracolumbar Region of Asymptomatic Subjects with Unilateral and Sham Straight Leg Raise Tests

Background

Normal displacement of the conus medullaris with unilateral and bilateral SLR has been quantified and the "principle of linear dependence" has been described.

Purpose

Explore whether previously recorded movements of conus medullaris with SLRs are i) primarily due to transmission of tensile forces transmitted through the neural tissues during SLR or ii) the result of reciprocal movements between vertebrae and nerves.

Study design

Controlled radiologic study.

Methods

Ten asymptomatic volunteers were scanned with a 1.5T magnetic resonance (MR) scanner using T2 weighted spc 3D scanning sequences and a device that permits greater ranges of SLR. Displacement of the conus medullaris during the unilateral and sham SLR was quantified reliably with a randomized procedure. Conus displacement in response to unilateral and sham SLRs was quantified and the results compared.

Results

The conus displaced caudally in the spinal canal by 3.54±0.87 mm (mean±SD) with unilateral (p≤.001) and proximally by 0.32±1.6 mm with sham SLR (p≤.542). Pearson correlations were higher than 0.99 for both intra- and inter-observer reliability and the observed power was 1 for unilateral SLRs and 0.054 and 0.149 for left and right sham SLR respectively.

Conclusions

Four relevant points emerge from the presented data: i) reciprocal movements between the spinal cord and the surrounding vertebrae are likely to occur during SLR in asymptomatic subjects, ii) conus medullaris displacement in the vertebral canal with SLR is primarily due to transmission of tensile forces through the neural tissues, iii) when tensile forces are transmitted through the neural system as in the clinical SLR, the magnitude of conus medullaris displacement prevails over the amount of bone adjustment.

The short term effects of straight leg raise neurodynamic treatment on pressure pain and vibration thresholds in individuals with spinally referred leg pain

BACKGROUND

Limited research exists for the effects of neurodynamic treatment techniques. Understanding short term physiological outcomes could help to better understand immediate benefits or harm of treatment.

OBJECTIVES

To assess the short-term effects of a straight leg raise (SLR) tensioner 'intervention' on pressure pain thresholds (PPT) and vibration thresholds (VT), and establish if additional factors influence outcome in individuals with spinally referred leg pain.

DESIGN

Experimental, repeated measures.

METHODS

Sixty seven participants (mean age (SD) 52.9 (13.3), 33 female) with spinally referred leg pain were divided into 3 sub-groups: somatic referred pain, radicular pain and radiculopathy. Individuals were assessed for central sensitisation (CS) and completed 5 disability and psychosocial questionnaires. PPT and VT were measured pre and post a 3 × 1 min SLR tensioner intervention.

RESULTS

No significant differences (p > 0.05) were found between the 3 groups for either outcome measure, or after treatment. Slight improvements in VT were seen in the radiculopathy group after treatment, but were not significant. Only 2 participants were identified with CS. Disability and psychological factors were not significantly different at baseline between the 3 sub-groups, and did not correlate with the outcome measures.

CONCLUSIONS

No beneficial effects of treatment were found, but the trend for a decrease in VT indicated that even in individuals with radiculopathy, no detrimental changes to nerve function occurred. Psychosocial factors and levels of disability did not influence short term outcome of SLR treatment.

Epidural steroids for spinal pain and radiculopathy: a narrative, evidence-based review

PURPOSE OF REVIEW

Epidural steroid injections (ESIs) are the most commonly performed intervention in pain clinics across the USA and worldwide. In light of the growing use of ESIs, a recent spate of highly publicized infectious complications, and increasing emphasis on cost-effectiveness, the utility of ESI has recently come under intense scrutiny. This article provides an evidence-based review of ESIs, including the most up-to-date information on patient selection, comparison of techniques, efficacy, and complications.

RECENT FINDINGS

The data strongly suggest that ESIs can provide short-term relief of radicular symptoms but are less convincing for long-term relief, and mixed regarding cost-effectiveness. Although some assert that transforaminal ESIs are more efficacious than interlaminar ESIs, and that fluoroscopy can improve treatment outcomes, the evidence to support these assertions is limited.

SUMMARY

The cost-effectiveness of ESI is the subject of great debate, and similar to efficacy, the conclusions one draws appear to be influenced by specialty. Because of the wide disparities regarding indications and utilization, it is likely that indiscriminate use is cost-ineffective, but that judicious use in well-selected patients can decrease healthcare utilization. More research is needed to better refine selection criteria for ESI, and to determine which approach, what dose, and how many injections are optimal.

Reduction of Leg Pain by Oxiplex Gel After Lumbar Discectomy in Patients With Predominant Leg Pain and Elevated Levels of Lower Back Pain: A Prospective, Randomized, Blinded, Multicenter Clinical Study

STUDY DESIGN

A prospective, randomized, blinded, multicenter clinical study.

OBJECTIVE

To evaluate carboxymethylcellulose/polyethylene oxide gel (Oxiplex) in improving clinical outcomes in subjects having predominant leg pain and elevated low back pain undergoing first-time lumbar discectomy for disk herniation.

SUMMARY OF BACKGROUND DATA

Clinical studies in the United States and Italy found that Oxiplex reduced leg pain after decompression surgery.

METHODS

A total of 68 subjects with herniated lumbar disk were enrolled and randomized into treatment (surgery plus gel) or surgery-only control groups. A prospective statistical analysis assessed the effect of gel in the severe back pain subgroup (prespecified as greater than or equal to median baseline back pain of the population studied). All subjects except 2 controls lost to follow-up completed the study. Preoperative and postoperative visual analogue scale leg pain scores were analyzed and compared between groups at 60 days after surgery.

RESULTS

There were no serious adverse events or neurological safety concerns reported in any patients. Gel-treated patients had statistically significantly lower visual analogue scale leg pain scores at study end compared with controls (P=0.0240), representing a 21% additional reduction in leg pain compared with surgery alone in the severe baseline back pain subgroup (P=0.0240). The proportion of subgroup patients experiencing zero leg pain at study end was significantly higher in the gel treatment group (60%) than in the control group (23%) (P=0.0411).

CONCLUSIONS

The data from this study confirm and extend results of 2 previous studies in Italy and the United States that reported statistically significantly greater reductions in leg pain in gel-treated patients with severe preoperative low back pain compared with patients who only underwent decompression surgery.

Part 3: Developing Methods of In Vivo MRI Measurement of Spinal Cord Displacement in the Thoracolumbar Region of Asymptomatic Subjects With Unilateral and Bilateral Straight Leg Raise Tests

STUDY DESIGN

Controlled radiological study.

OBJECTIVE

Verify (1) whether conus medullaris displacement varies with the range of hip flexion and (2) whether the acquired data support the "principle of linear dependence."

SUMMARY OF BACKGROUND DATA

We have previously quantified normal displacement of the conus with unilateral and bilateral straight leg raise (SLR) and have described the "principle of linear dependence." However, we have since effected methodological advances that have produced data that surpass previous studies.

METHODS

Ten asymptomatic volunteers were scanned with a 1.5-T magnetic resonance scanner using T2-weighted spc 3-dimensional scanning sequences and a device that permits greater ranges of SLR. Displacement of the conus medullaris during the unilateral and bilateral SLRs was quantified reliably with a randomized procedure.

RESULTS

Pearson correlations were higher than 0.99 for both intra- and interobserver reliability and the observed power was 1 for each tested maneuver. The conus displaced caudally in the spinal canal by 3.54 ± 0.87 mm (μ ± SD) with unilateral (P ≤ 0.001) and 7.42 ± 2.09 mm with bilateral SLR (P ≤ 0.001).

CONCLUSION

To the authors' knowledge, these are the first data on noninvasive, in vivo, normative measurement of spinal cord displacement with the SLR test at 60° of hip flexion. Conus medullaris displacement increased with hip flexion angle, while maintaining the relationship between magnitude of conus displacement and number of nerve roots involved into the movement, supporting the "principle of linear dependence." The use of T2-weighted spc 3-dimensional sequence allows for better reliability testing, which is important for future clinical utility.

LEVEL OF EVIDENCE

5.

Detection of Position-Related Sciatic Nerve Dysfunction by Somatosensory Evoked Potentials During Spinal Surgery

It is well established that intraoperative somatosensory evoked potentials (SSEPs) are sensitive to plexus and peripheral nerve dysfunction related to malpositioning of patients during spinal surgery. While most reports focus on upper extremity nerve or brachial plexus effects, there is very little on detection of sciatic nerve compromise. Recording of the SSEP at the popliteal fossa is a common strategy to aid in troubleshooting stimulus-related problems or distal peripheral tibial nerve failure; yet position-related sciatic nerve effects may not be realized by changes in the popliteal fossa response. Three posterior lumbar surgeries are reviewed in which there was evidence of proximal lower extremity peripheral nerve dysfunction related to positioning. Loss of posterior tibial nerve SSEPs with preservation of the peripheral popliteal fossa response recording occurred in the absence of critical surgical manipulations. Efforts at repositioning and release of tension on the lower limbs promptly resulted in recovey of lost responses. Two of the three cases involved patients in a kneeling position with a tight strap across the posterior thigh. Standard SSEP recordings used in intraoperative neuromonitoring do not specifically localize intraoperative changes to the sciatic nerve; thus, such changes affecting SSEPs above the popliteal fossa mimic iatrogenic changes occurring at the surgical site. These case reports show that when the stage of surgery does not support iatrogenic changes, malpositioning affecting sciatic nerve should be considered, especially for patients placed in a kneeling position on an Andrews frame.

Delayed-onset ulnar neuritis after release of elbow contractures: clinical presentation, pathological findings, and treatment

BACKGROUND

Little information exists regarding delayed-onset ulnar neuritis (DOUN) after arthroscopic release of elbow contractures.

PURPOSE

To describe, in a large cohort of patients, the clinical presentation of and risk factors for developing DOUN after arthroscopic release of elbow contractures.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective study of 565 consecutive arthroscopic releases of elbow contractures was conducted. Essentially, DOUN was defined as ulnar neuritis or neuropathy, or worsening of pre-existing ulnar nerve symptoms, that developed postoperatively in patients with normal neurological examination findings immediately after surgery. After inclusion and exclusion criteria were met, 235 contracture releases in patients who had not undergone any ulnar nerve surgery remained and were used for the analysis of risk factors with a multivariate logistic regression analysis.

RESULTS

Twenty-six patients (11%) developed DOUN. The patients fell into 1 of 3 distinct groups. Fifteen (58%) presented with rapidly progressive DOUN, characterized by rapidly progressive sensorimotor ulnar neuropathy, increasing pain at the cubital tunnel during end-range flexion and/or extension, and rapidly deteriorating range of motion within the first week after surgery. Urgent ulnar subcutaneous nerve transposition was performed within 1 or 2 days of diagnosis. Eight (31%) presented with nonprogressive DOUN, characterized by mild sensory ulnar neuropathy, neither motor weakness nor substantial pain at the cubital tunnel, or loss of motion. Three (12%) presented with slowly progressive DOUN, characterized by the insidious onset of mild ulnar neuropathy. Significant risk factors for DOUN included a diagnosis of heterotopic ossification (odds ratio, 31; 95% CI, 5-191; P < .001), preoperative neurological symptoms (odds ratio, 6; 95% CI, 2-19; P = .001), and preoperative arc of motion (odds ratio, 0.97 per degree of motion; 95% CI, 0.96-0.99; P = .02).

CONCLUSION

Delayed-onset ulnar neuritis is an important complication of arthroscopic release of elbow contractures. We recommend a high index of suspicion and monitoring patients with progressive loss of elbow motion and end-range pain for evidence of subclinical ulnar neuritis.

Lumbar radiculopathy and its neurobiological basis

Lumbar radiculopathy, a group of diseases in which the dorsal root ganglia (DRG) or dorsal roots are adversely affected by herniated discs or spinal stenosis, are clinically characterized by spontaneous and evoked types of pain. The pain is underpinned by various distinct pathophysiological mechanisms in the peripheral and central nervous systems. However, the diagnosis of lumbar radiculopathy is still unsatisfactory, because the association of the pain with the neurobiological basis of radiculopathy is largely unknown. Several animal models used to explore the underlying neurobiological basis of lumbar radiculopathy could be classified as mechanical, chemical, or both based on the component of injury. Mechanical injury elevates the intraneural pressure, reduces blood flow, and eventually establishes ischemia in the dorsal root and the DRG. Ischemia may induce ischemic pain and cause nerve damage or death, and the subsequent nerve damage or death may induce neuropathic pain. Chemical injury predominately induces inflammation surrounding the dorsal roots or DRG and consequent inflammatory mediators cause inflammatory pain. Furthermore, DRG neurons sensitized by inflammatory mediators are hypersensitive to innocuous mechanical force (stretch or compression) and responsible for mechanical allodynia in radiculopathy. As well, central sensitization in the spinal cord may play an important role in pain generation in lumbar radiculopathy. Increasing knowledge of pain-generating mechanisms and their translation into clinical symptoms and signs might allow for dissecting the mechanisms that operate in each patient. With precise clinical phenotypic characterization of lumbar radiculopathy and its connection to a specific underlying mechanism, we should be able to design optimal treatments for individuals. This review discusses the present knowledge of lumbar radiculopathy and proposes a novel mechanism-based classification.

2014 young investigator award winner: In vivo magnetic resonance imaging measurement of spinal cord displacement in the thoracolumbar region of asymptomatic subjects: part 2: comparison between unilateral and bilateral straight leg raise tests

STUDY DESIGN

Controlled radiological study.

OBJECTIVE

Ascertain if a difference exists in the mechanical effects on the cord between the unilateral and bilateral straight leg raise (SLR) and to verify whether the effect on the spinal cord may be cumulative between the two.

SUMMARY OF BACKGROUND DATA

To the authors' knowledge these are the first data on noninvasive, in vivo, normative measurement of spinal cord displacement with bilateral SLR test.

METHODS

Sixteen asymptomatic volunteers were scanned with 1.5-T magnetic resonance scanner (Siemens Avanto, Erlangen, Germany) using T2-weighted turbo spin-echo fat-saturation sequence. The displacement of the medullar cone relative to the vertebral endplate of the adjacent vertebra during the passive bilateral SLR was quantified and compared with the position of the conus in the neutral (anatomic) position and with unilateral SLR. Each movement was performed twice for evaluation of reproducibility. The measurements were repeated by 2 observers. Four practitioners performed the maneuvers in a random sequence to avoid series effects.

RESULTS

Compared with the neutral (anatomic) position, the medullar cone displaced caudally in the spinal canal by 2.33 ± 1.2 mm (μ ± SD) with unilateral (P ≤ 0.001) and 4.58 ± 1.48 mm with bilateral SLR (P ≤ 0.001). Statistical significance was also reached for bilateral versus unilateral SLR (P ≤ 0.001). Spearman correlations proved higher than 0.99 for intra and interobserver reliability, and 0.984 for results reproducibility in bilateral SLR.

CONCLUSION

The caudal displacement of the medullar cone was significantly greater (almost double) with the bilateral SLR than the unilateral SLR. We hypothesize that this greater movement may be because more force was transmitted to the cord through a larger number nerve roots with the bilateral than unilateral SLR. The high correlation values in this study show that these movements are consistent and reproducible. This study offers baseline measurements on which further studies in diagnosis and treatment of lumbar disc protrusion and radiculopathy may be developed.

2014 young investigator award winner: In vivo magnetic resonance imaging measurement of spinal cord displacement in the thoracolumbar region of asymptomatic subjects: part 1: straight leg raise test

STUDY DESIGN

Controlled radiological study.

OBJECTIVE

To investigate noninvasively in vivo spinal cord displacement in the vertebral canal during the passive straight leg raise (SLR) in asymptomatic subjects. The basic assumption is that the cord follows L5 and S1 nerve roots displacement by similar magnitude and direction (principle of linear dependence).

SUMMARY OF BACKGROUND DATA

It is generally accepted that the SLR produces some caudal movement mainly of L5 and S1 nerve roots, but the magnitude of this displacement is still a matter of debate.

METHODS

Sixteen asymptomatic volunteers were scanned with 1.5-T magnetic resonance scanner (Siemens Avanto, Erlangen, Germany) using T2-weighted turbo spin-echo fat-saturation sequence. The displacement of the medullar cone relative to the vertebral endplate of the adjacent vertebra during the passive SLR was quantified and compared with the position of the conus in the neutral (anatomic) position. Each movement was performed twice for evaluation of reproducibility. The measurements were repeated by 2 observers. Four practitioners performed the maneuvers in a random sequence to avoid series effects.

RESULTS

Compared with the neutral (anatomic) position, the medullar cone displaced caudally in the spinal canal by 2.31 ± 1.2 mm with right (P ≤ 0.001) and 2.35 ± 1.2 mm with left SLR (P ≤ 0.001). Spearman correlations proved higher than 0.99 for intra and interobserver reliability, as well as results reproducibility testing for each maneuver.

CONCLUSION

The data show that the spinal cord in the thoracolumbar region slides distally in response to the clinically applied SLR test. The high correlation values in this study show that these movements are consistent and reproducible. Because of the neural continuum, the authors speculate that this movement might be directly proportional to the sliding of the L5 and S1 neural roots. This study offers baseline measurements on which further studies in diagnosis of lumbar disc protrusion and radiculopathy may be developed.

Skin, fascias, and scars: symptoms and systemic connections

Every element or cell in the human body produces substances that communicate and respond in an autocrine or paracrine mode, consequently affecting organs and structures that are seemingly far from each other. The same also applies to the skin. In fact, when the integrity of the skin has been altered, or when its healing process is disturbed, it becomes a source of symptoms that are not merely cutaneous. The skin is an organ, and similar to any other structure, it has different functions in addition to connections with the central and peripheral nervous system. This article examines pathological responses produced by scars, analyzing definitions and differences. At the same time, it considers the subcutaneous fascias, as this connective structure is altered when there is a discontinuous cutaneous surface. The consequence is an ample symptomatology, which is not limited to the body area where the scar is located, such as a postural or trigeminal disorder.

Intramuscular pressure of the multifidus muscle and low-back pain after posterior lumbar interbody fusion: comparison of mini-open and conventional approaches

Object

This randomized study was designed to elucidate the time course of the perioperative development of intramuscular multifidus muscle pressure after posterior lumbar interbody fusion (PLIF) and to investigate whether the route of pedicle screw insertion affects this pressure and resultant low-back pain. Although several studies have focused on intramuscular pressure associated with posterior lumbar surgery, those studies examined intramuscular pressure generated by the muscle retractors during surgery. No study has investigated the intramuscular pressure after PLIF.

Methods

Forty patients with L4–5 degenerative spondylolisthesis were randomly assigned to undergo either the mini-open PLIF procedure with pedicle screw insertion between the multifidus and longissimus muscles (n = 20) or the conventional PLIF procedure via a midline approach only (n = 20). Intramuscular pressure was measured 5 times (at 30 minutes and at 6, 12, 24, and 48 hours after surgery) with an intraoperatively installed sensor. Concurrently, the FACES Pain Rating Scale score for low-back pain and the total dose of postoperative analgesics were recorded.

Results

With the patients in the supine position, for both groups the mean pressure values were consistently 40–50 mm Hg, which exceeded the critical capillary pressure of the muscle. With the patients in the lateral decubitus position, the pressure decreased over time (from 14 to 9 mm Hg in the mini-open group and from 20 to 10 mm Hg in the conventional group). Among patients in the mini-open group, the pressure was lower, but the difference was not statistically significant. Postoperative pain and postoperative analgesic dosages were also lower .

Conclusions

To the authors' knowledge, this is the first study to evaluate postoperative intramuscular pressure after PLIF. Although the results did not demonstrate a significant difference in the intramuscular pressure between the 2 types of PLIF, mini-open PLIF was associated with less pain after surgery. Clinical trial registration no.: UMIN000010069 (www.umin.ac.jp/ctr/index.htm).

Epidural steroids: a comprehensive, evidence-based review

Epidural steroid injections (ESIs) are the most widely utilized pain management procedure in the world, their use supported by more than 45 placebo-controlled studies and dozens of systematic reviews. Despite the extensive literature on the subject, there continues to be considerable controversy surrounding their safety and efficacy. The results of clinical trials and review articles are heavily influenced by specialty, with those done by interventional pain physicians more likely to yield positive findings. Overall, more than half of controlled studies have demonstrated positive findings, suggesting a modest effect size lasting less than 3 months in well-selected individuals. Transforaminal injections are more likely to yield positive results than interlaminar or caudal injections, and subgroup analyses indicate a slightly greater likelihood for a positive response for lumbar herniated disk, compared with spinal stenosis or axial spinal pain. Other factors that may increase the likelihood of a positive outcome in clinical trials include the use of a nonepidural (eg, intramuscular) control group, higher volumes in the treatment group, and the use of depo-steroid. Serious complications are rare following ESIs, provided proper precautions are taken. Although there are no clinical trials comparing different numbers of injections, guidelines suggest that the number of injections should be tailored to individual response, rather than a set series. Most subgroup analyses of controlled studies show no difference in surgical rates between ESI and control patients; however, randomized studies conducted by spine surgeons, in surgically amenable patients with standardized operative criteria, indicate that in some patients the strategic use of ESI may prevent surgery.

A review of the role of epidural percutaneous adhesiolysis

SUMMARY Low back and leg pain can arise for a variety reasons, including epidural scarring caused by post lumbar surgery syndrome, infection or bleeding. Treatment options for low back and/or leg pain caused by epidural scarring include conservative approaches, such as physical therapy and medication management, and procedures, such as epidural steroid injections. Despite appropriate treatment, pain can persist in these patients. Surgery is often not an option for patients whose pain is caused by scarring. Percutaneous adhesiolysis is a minimally invasive technique, which is effective in treating refractory low back and leg pain arising from epidural scarring. It involves the use of a spring-wound, shear-resistant catheter, ideally placed in the ventrolateral aspect of the epidural space for the lysis of adhesions, allowing medications to reach the involved nerve and removing compression of the nerve. After mechanical lysis of adhesions, relatively large volumes of local anesthetic, saline, steroid and radiopaque contrast material are injected. Either hypertonic or normal saline may be used, along with hyaluronidase. After the procedure, the patient should perform exercises to stretch the nerve roots. While this has been studied as a caudal procedure, thoracic and cervical procedures have also been described, using both transforaminal and interlaminar approaches. With trained practitioners, complications are minimal. The effectiveness of the procedure has been documented by high-quality randomized controlled trials and observational studies for both postlumbar surgery syndrome and spinal stenosis.

Clinical outcomes after lumbar fusion complicated by deep wound infection: a case-control study

STUDY DESIGN

A propensity score-matched case-control study.

OBJECTIVE

To evaluate the 2-year clinical outcomes of patients who have undergone instrumented spinal fusions complicated by deep wound infections and compare them with a propensity score-matched control group who did not have infections.

SUMMARY OF BACKGROUND DATA

Postoperative infection after instrumented spinal fusion is a major complication, often resulting in substantial short-term morbidity. However, there is little literature reviewing how these patients do in the longer term after their infection has been managed.

METHODS

Thirty patients were identified who underwent instrumented lumbar spinal fusion with complete preoperative and 2-year postoperative outcome measures and had acute (#3 mo) postoperative deep wound infections necessitating irrigation and debridement. Outcome measures included the Oswestry Disability Index, 36-Item Short Form Health Survey Physical and Mental composite summaries, and numeric rating scales (0-10) for back and leg pain. A noninfected control group was identified using propensity score-matching techniques based on demographics, baseline clinical outcome measures, and surgical characteristics. Two-year postoperative outcome measures of both groups were compared. The proportion of patients achieving the minimum clinically important difference for the outcome measures was also assessed. Independent t tests were used to compare continuous variables, and Fisher exact test was used to compare categorical variables between the 2 groups.

RESULTS

Consistent with the propensity score-matching technique, there were no significant demographic or surgical differences between the 2 study groups at baseline. Oswestry Disability Index, 36-Item Short Form Health Survey Physical Composite Summary, and back and leg pain scores were statistically significantly better at 2 years postoperative than at baseline in both groups. However, at 2 years postoperative, the infection group had a statistically significantly worse back pain score compared with the control group (6.45 vs. 4.70, P = 0.020). Also, a greater proportion of patients in the control group (18, 60%) achieved minimum clinically important difference for Oswestry Disability Index than those in the infection group (8, 27%, P = 0.018).

CONCLUSION

This study demonstrates that patients with acute postoperative deep wound infections after instrumented lumbar spinal fusion have improved outcome measures after surgery but have greater back pain and a decreased probability of achieving minimum clinically important difference.

Oxiplex reduces leg pain, back pain, and associated symptoms after lumbar discectomy

STUDY DESIGN

Prospective, randomized, blinded clinical trial.

OBJECTIVE

To evaluate effectiveness of Oxiplex gel for reduction of pain and associated symptoms after lumbar discectomy.

SUMMARY OF BACKGROUND DATA

Oxiplex gel (carboxymethylcellulose, polyethylene oxide, and calcium) is used during discectomy to coat the surgical site for reduction of pain and symptoms after lumbar discectomy.

METHODS

Patients undergoing single-level lumbar discectomy performed by laminectomy or laminotomy and randomized to receive either surgery plus Oxiplex gel (treatment group) or surgery alone (control group) were assessed 6 months after surgery using (1) a quality of life questionnaire (Lumbar Spine Outcomes Questionnaire [LSOQ]) and (2) clinical evaluations.

RESULTS

There were no statistically significant differences in baseline demographics, surgical procedures, LSOQ scores, and clinical evaluations between treatment (N = 177) and control (N = 175) groups. More gel-treated patients were satisfied with outcome of their surgical treatment than control patients (P = 0.05). The gel-treated group showed greater reductions in pain and symptoms from baseline compared with surgery-only controls. Additional benefits of gel were consistently shown in reduction of leg and back pain at 6 months in the patient population having substantial back pain at baseline (greater than or equal to the median LSOQ pain score of 63). In that population, there was a statistically significant reduction of leg pain and back pain (P < 0.01) in the treatment group compared with controls. Fewer patients in the treatment group had abnormal musculoskeletal physical examinations at 6 months compared with controls. There were no cases of cerebrospinal fluid leaks and no differences in laboratory values or vital signs. Patients in the treatment group had less hypoesthesia, paraesthesia, sensory loss, and fewer reoperations during the 6-month follow-up than controls (1 vs. 6).

CONCLUSION

These data demonstrate improvements in clinical outcomes resulting from the use of Oxiplex gel in discectomy procedures for treatment of lumbar disc herniation.