Lumbar plexus safe working zones with lateral lumbar interbody fusion: a systematic review and meta-analysis

PURPOSE

Significant risk of injury to the lumbar plexus and its departing motor and sensory nerves exists with lateral lumbar interbody fusion (LLIF). Several cadaveric and imaging studies have investigated the lumbar plexus position with respect to the vertebral body anteroposterior plane. To date, no systematic review and meta-analysis of the lumbar plexus safe working zones for LLIF has been performed.

METHODS

This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies reporting on the position of the lumbar plexus with relation to the vertebral body in the anteroposterior plane were identified from a PubMed database query. Quantitative analysis was performed using Welch's t test.

RESULTS

Eighteen studies were included, encompassing 1005 subjects and 2472 intervertebral levels. Eleven studies used supine magnetic resonance imaging (MRI) with in vivo subjects. Seven studies used cadavers, five of which performed dissection in the left lateral decubitus position. A significant correlation (p < 0.001) existed between anterior lumbar plexus displacement and evaluation with in vivo MRI at all levels between L1-L5 compared with cadaveric measurement. Supine position was also associated with significant (p < 0.001) anterior shift of the lumbar plexus at all levels between L1-L5.

CONCLUSIONS

This is the first comprehensive systematic review and meta-analysis of the lumbar neural components and safe working zones for LLIF. Our analysis suggests that the lumbar plexus is significantly displaced ventrally with the supine compared to lateral decubitus position, and that MRI may overestimate ventral encroachment of lumbar plexus.

Applicative value of T2 mapping in evaluating lumbosacral nerve root injury induced by lumbosacral disc herniation

BACKGROUND

To alleviate the damage caused by nerve root entrapment mediated by lumbosacral disc herniation (LDH), an imaging method that allows quantitative evaluation of the lumbosacral nerve injury is necessary.

PURPOSE

To investigate the diagnostic value of magnetic resonance (MR) T2 mapping in nerve root injury caused by LDH.

MATERIAL AND METHODS

A total of 70 patients with unilateral sciatic nerve pain and 35 healthy volunteers were divided into three groups: LDH with nerve root entrapment; LDH without nerve root entrapment; and 35 healthy volunteers. All participants underwent 3.0-T MR with T1-weighted (T1W) imaging, T2-weighted (T2W) imaging, and T2-mapping images. T2 was measured and observed with the left and right nerve roots of the L4-S1 segments in healthy volunteers; the differences between the three groups were compared. T2 and the relaxation rate of nerve root injury were analyzed.

RESULTS

T2 showed significant differences among the three groups (F = 89.494; P = 0.000), receiver operating characteristic curve revealed that the T2 relaxation threshold was 79 ms, the area under curve (AUC) area was 0.86, sensitivity was 0.77, and specificity was 0.74; the T2 relaxation rate was 1.06, the AUC area was 0.88, sensitivity was 0.74, and specificity was 0.85.

CONCLUSION

T2 mapping could quantitatively evaluate the nerve root injury with lumbar disc degeneration. Hence, it can be used for the clinical evaluation of nerve root entrapment caused by LDH.

Motor Unit Number Index in Evaluating Patients With Lumbar Spinal Stenosis

OBJECTIVE

Motor unit number index is a quantitative electrophysiological measure that provides an index of the number of motor neurons supplying a muscle. The aim of this exploratory study was to assess the utility of motor unit number index in the evaluation of patients with lumbar spinal stenosis.

DESIGN

Participants were assigned to three groups: clinical and radiological lumbar stenosis (lumbar spinal stenosis with neurogenic intermittent claudication), group A; radiological lumbar spinal stenosis without neurogenic intermittent claudication, group B; and a control group, group C. Patients self-rated their pain and functional disability using the numerical rating scale and a series of functional questionnaires. An electromyographer performed nerve conduction tests, electromyography, and motor unit number index testing.

RESULTS

Seventeen patients completed the study. There were 9, 5, and 3 patients in groups A, B, and C, respectively. There were no discernable differences in motor unit number index values of any individual muscle or combined motor unit number index score between the three groups. Motor unit number index values did not correlate to pain/functional measures.

CONCLUSIONS

In this exploratory study, motor unit number index did not demonstrate discriminatory ability between patients with lumbar spinal stenosis and was not correlated with pain and functional measures. Further study is needed to explore motor unit number index's role in longitudinal evaluation of patients with the clinical syndrome of lumbar spinal stenosis.

Cost-Effectiveness of Radiofrequency Denervation for Patients With Chronic Low Back Pain: The MINT Randomized Clinical Trials

OBJECTIVES

To evaluate the cost-effectiveness of radiofrequency denervation when added to a standardized exercise program for patients with chronic low back pain.

METHODS

An economic evaluation was conducted alongside 3 pragmatic multicenter, nonblinded randomized clinical trials (RCTs) in The Netherlands with a follow up of 52 weeks. Eligible participants were included between January 1, 2013, and October 24, 2014, and had chronic low back pain; a positive diagnostic block at the facet joints (n = 251), sacroiliac (SI) joints (n = 228), or a combination of facet joints, SI joints, and intervertebral discs (n = 202); and were unresponsive to initial conservative care. Quality-adjusted life-years (QALYs) and societal costs were measured using self-reported questionnaires. Missing data were imputed using multiple imputation. Bootstrapping was used to estimate statistical uncertainty.

RESULTS

After 52 weeks, no difference in costs between groups was found in the facet joint or combination RCT. The total costs were significantly higher for the intervention group in the SI joint RCT. The maximum probability of radiofrequency denervation being cost-effective when added to a standardized exercise program ranged from 0.10 in the facet joint RCT to 0.17 in the SI joint RCT irrespective of the ceiling ratio, and 0.65 at a ceiling ratio of €30 000 per QALY in the combination RCT.

CONCLUSIONS

Although equivocal among patients with symptoms in a combination of the facet joints, SI joints, and intervertebral discs, evidence suggests that radiofrequency denervation combined with a standardized exercise program cannot be considered cost-effective from a societal perspective for patients with chronic low back pain originating from either facet or SI joints in a Dutch healthcare setting.

The phenotypic morphology of human lumbar plexus roots associated with changes in the thoracolumbar vertebral count and trade-off

This study investigated the developmental basis for the human phenotypic morphology of the interaction between the vertebrae and the nerve plexus by evaluating changes in the human lumbar plexus according to various thoracolumbar formulas. The dissection found that the changes in lumbar nerve roots reported by experimental embryology studies to be concomitant with thoracolumbar trade-off, i.e., a change in vertebrae from thoracic to lumbar with no change in the overall thoracolumbar count, were not apparent in humans with the usual 17 or mutant 16 thoracolumbar vertebrae. When vertebral changes in two segments were examined by comparing spines with a reduced thoracolumbar count of 16 to those with an increased count of 18, this tended to show only a single-segment caudal shift of the lumbar plexus. We cannot provide evidence for the phylogenetic difference in the concomitant changes of lumbar nerves and vertebrae, but comparisons between experimental rodents and humans highlighted fewer and shorter lumbar vertebra and more complicated lumbar plexus in humans. Therefore, these multiple differences may contribute to a human phenotypic morphology that is not evident in the concomitant transformation of vertebrae and lumbar nerves reported in experimental rodents.

Erdheim-Chester disease mimicking lumbar nerve schwannoma: case report and literature review

Introduction

Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis. The clinical spectrum of ECD is diverse, varying from asymptomatic focal lesion to life-threatening multisystem infiltration. Neurological manifestations of ECD are common, mostly due to the involvement of the central nerve system. However, spinal nerve or peripheral nerve involvement has rarely been mentioned.

Case presentation

Herein, we present a case of a 32-year-old female patient complaining about radiating pain on the front and lateral side of her left thigh for 2 months. Spinal MRI with contrast enhancement showed a space-occupying lesion on the left L3/L4 intervertebral foramen, indicating an initial diagnosis of lumbar nerve schwannoma. The patient underwent surgery to remove the mass and decompress the lumbar nerve. Postoperative histological examination revealed the diffuse infiltration of foamy histiocytes that were CD68+, CD163+, and CD1a- on immunostaining, which confirmed the diagnosis of Erdheim-Chester disease. The radiating pain was gradually alleviated and PET-CT was performed but showed no further involvement of ECD.

Discussion

To the best of our knowledge, this is the first case of ECD demonstrated as an infiltrative mass on the spinal nerve, with imaging manifestations and compression symptoms similar to those of peripheral nerve schwannoma.

Prevalence of benign osseous lesions of the spine and association with spinal pain in the general population in whole body MRI

Background

Benign osseous lesions of the spine are common but precise population prevalence estimates are lacking. Our study aimed to provide the first population-based prevalence estimates and examine association with back and neck pain.

Materials and methods

We used data from the population-based Study of Health in Pomerania (SHIP). Whole-body MRI examinations (1.5 Tesla: T1, T2, and TIRM weightings) were available from 3,259 participants. Readings of the spinal MRI images were conducted according to a standardized protocol by a single reader (JS). The intra-rater reliability was greater than Kappa values of 0.98. Pain measures included the seven-day prevalence of spine pain and neck pain, and average spine pain intensity due to spine pain during the past three months.

Results

We found 1,200 (36.8%) participants with at least one osseous lesion (2,080 lesions in total). Osseous lesions were less common in men than in women (35.5% vs 38.9%; P = .06). The prevalence of osseous lesions was highest at L2 in both sexes. The prevalence of osseous lesions increased with age. Up to eight osseous lesions were observed in a single subject. Hemangioma (28%), and lipoma (13%) occurred most often. Sclerosis (1.7%), aneurysmal bone cysts (0.7%), and blastoma (0.3%) were rare. Different osseous lesions occurred more often in combination with each other. The association with back or neck pain was mostly negligible.

Conclusion

Osseous lesions are common in the general population but of no clinical relevance for spinal pain. The prevalence of osseous lesions varied strongly across different regions of the spine and was also associated with age and gender. Our population-based data offer new insights and assist in judging the relevance of osseous lesions observed on MRIs of patients.

Effect of Ultrasound-Guided Intercostal Nerve Block Versus Fluoroscopy-Guided Epidural Nerve Block in Patients With Thoracic Herpes Zoster: A Comparative Study

OBJECTIVES

To compare the efficacy of a conventional fluoroscopy-guided epidural nerve block and an ultrasound (US)-guided intercostal nerve block in patients with thoracic herpes zoster (HZ).

METHODS

This work was a comparative study of 38 patients with thoracic HZ pain and a chest wall herpetic eruption, aged 18 years or older, with pain intensity of 5 or greater on a numeric rating scale (NRS) for less than a 1-month duration. Patients were consecutively enrolled and assigned to 2 groups in which the intervention was either the US-guided intercostal nerve block or the fluoroscopy-guided epidural nerve block approach with the addition of a 5-mL mix of 2.5 mg of dexamethasone plus 0.5% lidocaine. The primary outcome measure was the NRS score reduction for the pain. Secondary outcomes included the duration of treatment, number of repeated injections until the final visit, and proportion of patients with pain relief after the first and final visits.

RESULTS

All patients within both intervention groups showed significant pain relief on the NRS at the final follow-up point (P < .05). There was no significant difference in the mean value of NRS improvement based on the intervention type. There was also no statistically significant difference in the duration of treatment and the frequency of injection for pain relief.

CONCLUSIONS

These findings showed that both the US-guided intercostal nerve block and the fluoroscopy-guided epidural nerve block were effective in patients with thoracic HZ. Compared data showed no significant differences in the pain reduction, duration of treatment, and frequency of injection. The US-guided intercostal nerve block, which is more accessible than the fluoroscopy-guided epidural nerve block, might be an alternative option for thoracic HZ.

Effectiveness of lumbar epidural injection in patients with chronic spinal stenosis accompanying redundant nerve roots

Redundant nerve root syndrome (RNRS) is a phenomenon characterized by the presence of elongated, enlarged, tortuous nerve roots in the lumbar subarachnoid space. It is unclear whether RNRS is caused by spinal stenosis or causes these symptoms.This study evaluated the effects of lumbar epidural steroid injection (LESI) on patients with RNRS and assessed factors associated with RNRS. This retrospective observational cohort study was conducted at a single pain clinic of a university hospital.The medical records of 172 outpatients presenting with low back and/or leg pain from July to December 2014 were analyzed. Pain intensity (numeric rating scale [NRS]) and functional status were assessed at baseline and 2, 4, and 12 weeks after the LESI. Patients were considered moderate responders if they showed a 3-point or >30% reduction in baseline NRS, or said "better than 30%," "a little better," or "I feel an effect." Patients were considered substantial responders if they showed a 5-point or >50% reduction in baseline NRS, or said "better than 50%," "very good," or "much better." Generalized estimating equation (GEE) analysis was performed to identify the factors associated with moderate response to LESI. Factors associated with RNRS were also determined by logistic regression analysis.The proportions of both moderate and substantial responders at 2, 4, and 12 weeks were significantly lower in patients with than without RNRS. GEE analysis showed that RNRS were the only factor significantly associated with moderate response to LESI (OR = 0.400; 95% CI, 0.253-0.632; P < .001). The distance from the conus medullaris to the closest level of stenosis was shorter in patients with than without RNRS (P < .001) and was the only independent factor associated with RNRS on multivariate logistic regression analysis (OR = 0.972; P < .001).LESI was less effective in patients with than without RNRS. The only independent factor significantly associated with RNRS was the distance from the conus medullaris to the nearest moderate stenosis.

Audit of Conservative Management of Chronic Low Back Pain in a Secondary Care Setting – Part I: Facet Joint and Sacroiliac Joint Interventions

The work of a chronic back pain service in secondary care in the West Midlands is reported. The service offers acupuncture, spinal injection procedures, osteopathy and a range of other interventions for patients whose back pain has not responded to conservative management. This section of the report focuses on injection procedures for lumbar facet joint and sacroiliac joint pain, which have been shown to be the cause of chronic low back pain in 16–40% and 13–19% of patients respectively. Diagnosis relies on the use of intra-articular or sensory nerve block injections with local anaesthetic. Possible treatments following diagnosis include intra-articular corticosteroid, radiofrequency denervation (for facet joint pain) or ligament prolotherapy injections (for sacroiliac joint pain). The results of several hospital audits are reported. At six month follow up, 50% of 38 patients undergoing radiofrequency denervation following diagnostic blocks for facet joint pain had improved by more than 50%, compared to 29% of 34 patients treated with intra-articular corticosteroid injection. Sixty three per cent of 19 patients undergoing prolotherapy following diagnostic block injection for sacroiliac joint pain had improved at six months, compared to 33% of 33 who had intra-articular corticosteroid. Both radiofrequency denervation and sacroiliac prolotherapy showed good long-term outcomes at one year.

Management of lumbar radiculopathy due to disc herniation with interlaminar epidural steroid injection in the presence of multilevel Tarlov cysts in the neural foramina: A case report

RATIONALE

Perineural cysts, commonly referred to as Tarlov cysts, are cerebrospinal fluid-filled dilations between the perineurium and endoneurium typically arising at the junction of posterior and dorsal root ganglia in the neural foramina. This anatomical location is in close proximity to usual needle trajectory during performing transforaminal epidural injection, and therefore presents a potential risk of dural puncture and associated complications.

PATIENT CONCERNS

Severe lower extremity pain interfering with activities of daily living.

DIAGNOSES

Lumbar radiculopathy secondary to left-sided L4-5 disc herniation in the presence of multilevel Tarlov cysts in the neural foramina.

INTERVENTIONS

Posterior interlaminar epidural steroid injection technique was preferred, as opposed to transforaminal approach, to avoid potential risk of dural puncture and associated complications in the presence of multilevel Tarlov cysts in the neural foramina.

OUTCOMES

The patient responded favorably to epidural steroid injection via interlaminar approach with complete resolution of pain, symptoms, and signs. There were no complications. The patient was able to tolerate physical therapy, wean pain medications, and achieve normal activities of daily living without any significant limitations.

LESSONS

In patients presenting with an MRI report of "Tarlov cysts", meticulous evaluation of diagnostic images should be an essential first step before considering invasive spinal procedures. Should there be any presence of Tarlov cyst in close proximity to planned needle trajectory, we recommend appropriate modification of spinal intervention to avoid potential complications.

Chemical lumbar sympathectomy in the treatment of recalcitrant erythromelalgia

OBJECTIVE

Erythromelalgia is highly disabling and treatment is often very challenging. There have been solitary case reports that it might benefit from sympathectomy. This study sought to evaluate the short-term and long-term efficacy of chemical lumbar sympathectomy (CLS) for treatment of recalcitrant erythromelalgia and try to identify a CLS-responsive subset.

METHODS

Patients with recalcitrant erythromelalgia were recruited from a tertiary hospital over a 10-year period. L3 to L4 CLS was performed using 5% phenol. The pain intensity score (visual analog scale [VAS] 0-10) was assessed before CLS and at 1 day, 1 week, 3 months, 6 months, 1 year, and 2 years after CLS. A VAS decrease of 90%-100% is defined as complete response, 60%-89% as major partial response. Relapse was defined by a return of a VAS score of 5 or higher. SCN9A gene mutations were screened.

RESULTS

Thirteen patients were enrolled, with a median age of 15 years. The mean follow-up was 6.2 ± 3.8 years. SCN9A gene mutation was identified in five patients having family histories. The VAS was 8.2 ± 2.0 at baseline; it decreased to 4.9 ± 2.7 at 1 day and 1.9 ± 3.0 at 1 week after CLS. Nine patients (69.2%) achieved complete response at 1 week after CLS, including three patients with SCN9A gene mutation. Among the three complete response patients having the gene mutation, two reverted to major partial response and one relapsed at 2 years after CLS. Among the six complete response patients without mutation, five maintained complete response and one relapsed. Among the four patients who did not achieve complete response, one patient died at 3.5 months and one patient had an amputation performed at 4 months after CLS.

CONCLUSIONS

CLS provides a valid option for the treatment of recalcitrant erythromelalgia. It takes about 1 week to achieve full efficacy. Relapse may occur, especially in patients with an SCN9A gene mutation.

Lumbar Sympathetic Block with Botulinum Toxin Type A and Type B for the Complex Regional Pain Syndrome

A lumbar sympathetic ganglion block (LSB) is a therapeutic method for complex regional pain syndrome (CRPS) affecting the lower limbs. Recently, LSB with botulinum toxin type A and B was introduced as a novel method to achieve longer duration of analgesia. In this study, we compared the botulinum toxin type A (BTA) with botulinum toxin type B (BTB) in performing LSB on patients with CRPS. LSB was performed with either BTA or BTB on patients with CRPS in their lower extremities. The length of time taken for patients to return to the pre-LSB pain score and the adverse effect of LSB with BTA/BTB were investigated. The median length of time taken for the patients to return to the pre-LSB pain score was 15 days for the BTA group and 69 days for the BTB group (P = 0.002). Scores on a visual analogue scale decreased in the patients of both groups, and no significant adverse effects were experienced. In conclusion, the administration of either BTA or BTB for LSB is a safe method to prolong the sympathetic blocking effect in patients with CRPS. BTB is more effective than BTA to prolong the sympathetic blocking effect in CRPS patients.

Periprosthetic UHMWPE Wear Debris Induces Inflammation, Vascularization, and Innervation After Total Disc Replacement in the Lumbar Spine

BACKGROUND

The pathophysiology and mechanisms driving the generation of unintended pain after total disc replacement (TDR) remain unexplored. Ultrahigh-molecular-weight polyethylene (UHMWPE) wear debris from TDRs is known to induce inflammation, which may result in pain.

QUESTIONS/PURPOSES

The purpose of this study was to determine whether (1) periprosthetic UHMWPE wear debris induces immune responses that lead to the production of tumor necrosis factor-α (TNFα) and interleukin (IL)-1ß, the vascularization factors, vascular endothelial growth factor (VEGF) and platelet-derived growth factor-bb (PDGFbb), and the innervation/pain factors, nerve growth factor (NGF) and substance P; (2) the number of macrophages is associated with the production of the aforementioned factors; (3) the wear debris-induced inflammatory pathogenesis involves an increase in vascularization and associated innervation.

METHODS

Periprosthetic tissues from our collection of 11 patients with contemporary TDRs were evaluated using polarized light microscopy to quantify UHMWPE wear particles. The major reason for revision (mean implantation time of 3 years [range, 1-6 years]) was pain. For control subjects, biopsy samples from four patients with degenerative disc disease with severe pain and autopsy samples from three normal patients with no history of back pain were also investigated. Immunohistochemistry and histology were used to identify secretory factors, macrophages, and blood vessels. Immunostained serial sections were imaged at ×200 magnification and using MATLAB and NIH ImageJ, a threshold was determined for each factor and used to quantify positive staining normalized to tissue sectional area. The Mann-Whitney U test was used to compare results from different patient groups, whereas the Spearman Rho test was used to determine correlations. Significance was based on p < 0.05.

RESULTS

The mean percent area of all six inflammatory, vascularization, and innervation factors was higher in TDR tissues when compared with normal disc tissues. Based on nonparametric data analysis, those factors showing the most significant increase included TNFα (5.17 ± 1.76 versus 0.05 ± 0.03, p = 0.02), VEGF (3.02 ± 1.01 versus 0.02 ± 0.002, p = 0.02), and substance P (4.15 ± 1.01 versus 0.08 ± 0.04, p = 0.02). The mean percent area for IL-1ß (2.41 ± 0.66 versus 0.13 ± 0.13, p = 0.01), VEGF (3.02 ± 1.01 versus 0.34 ± 0.29, p = 0.04), and substance P (4.15 ± 1.01 versus 1.05 ± 0.46, p = 0.01) was also higher in TDR tissues when compared with disc tissues from patients with painful degenerative disc disease. Five of the factors, TNFα, IL-1ß, VEGF, NGF, and substance P, strongly correlated with the number of wear particles, macrophages, and blood vessels. The most notable correlations included TNFα with wear particles (p < 0.001, ρ = 0.63), VEGF with macrophages (p = 0.001, ρ = 0.71), and NGF with blood vessels (p < 0.001, ρ = 0.70). Of particular significance, the expression of PDGFbb, NGF, and substance P was predominantly localized to blood vessels/nerve fibers.

CONCLUSIONS

These findings indicate wear debris-induced inflammatory reactions can be linked to enhanced vascularization and associated innervation/pain factor production at periprosthetic sites around TDRs. Elucidating the pathogenesis of inflammatory particle disease will provide information needed to identify potential therapeutic targets and treatment strategies to mitigate pain and potentially avoid revision surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Anatomical evaluation of lumbar nerves using diffusion tensor imaging and implications of lateral decubitus for lateral transpsoas approach

PURPOSE

Recently, lateral interbody fusion (LIF) has become more prevalent, and evaluation of lumbar nerves has taken on new importance. We report on the assessment of anatomical relationships between lumbar nerves and vertebral bodies using diffusion tensor imaging (DTI).

METHODS

Fifty patients with degenerative lumbar disease and ten healthy subjects underwent DTI. In patients with lumbar degenerative disease, we studied nerve courses with patients in the supine positions and with hips flexed. In healthy subjects, we evaluated nerve courses in three different positions: supine with hips flexed (the standard position for MRI); supine with hips extended; and the right lateral decubitus position with hips flexed. In conjunction with tractography from L3 to L5 using T2-weighted sagittal imaging, the vertebral body anteroposterior span was divided into four equally wide zones, with six total zones defined, including an anterior and a posterior zone (zone A, zones 1-4, zone P). We used this to characterize nerve courses at disc levels L3/4, L4/5, and L5/S1.

RESULTS

In patients with degenerative lumbar disease, in the supine position with hips flexed, all lumbar nerve roots were located posterior to the vertebral body centers in L3/4 and L4/5. In healthy individuals, the L3/4 nerve courses were displaced forward in hips extended compared with the standard position, whereas in the lateral decubitus position, the L4/5 and L5/S nerve courses were displaced posteriorly compared with the standard position.

CONCLUSIONS

The L3/4 and L4/5 nerve roots are located posterior to the vertebral body center. These were found to be offset to the rear when the hip is flexed or the lateral decubitus position is assumed. The present study is the first to elucidate changes in the course of the lumbar nerves as this varies by position. The lateral decubitus position or the position supine with hips flexed may be useful for avoiding nerve damage in a direct lateral transpsoas approach. Preoperative DTI seems to be useful in evaluating the lumbar nerve course as it relates anatomically to the vertebral body.

Ultrasound versus fluoroscopy-guided medial branch block for the treatment of lower lumbar facet joint pain: A retrospective comparative study

The aim of this study was to compare the mid-term effects and benefits of ultrasound (US)-guided and fluoroscopy (FL)-guided medial branch blocks (MBBs) for chronic lower lumbar facet joint pain through pain relief, functional improvement, and injection efficiency evaluation.Patients with chronic lumbar facet joint pain who received US (n = 68) or FL-guided MBBs (n = 78) were included in this retrospective study. All procedures were performed under FL or US guidance. Complication frequency, therapeutic effects, functional improvement, and the injection efficiency of MBBs were compared at 1, 3, and 6 months after the last injection.Both the Oswestry Disability Index (ODI) and the verbal numeric pain scale (VNS) improved at 1, 3, and 6 months after the last injections in both groups. Statistical differences were not observed in ODI and VNS between the groups (P > .05). The proportion of patients who reported successful treatment outcomes showed no significant differences between the groups at different time points. Logistic regression analysis showed that sex, pain duration, injection methods, number of injections, analgesic use, and age were not independent predictors of a successful outcome. US guidance was associated with a significantly shorter performance time.US-guided MBBs did not show significant differences in analgesic effect and functional improvement compared with the FL-guided approach. Therefore, by considering our data from this retrospective study, US-guided MBBs warrant consideration in the conservative management of lower lumbar facet joint pain.

[THE APPLICATION OF ANTIHOMOTOXIC DRUG PREPARATIONS IN THE COMPLEX TREATMENT IN PATIENTS WITH NEUROLOGICAL MANIFESTATIONS OF LUMBAR OSTEOCHONDROSIS]

The expediency of application homeosyniatry by preparations of Traumel S and Placenta Compositum after the offered chart in relation to a complex with classic acupuncture and in relation to the group of the generally accepted treatment has been proved in complex treatment patients with reflex syndromes of lumbar osteochondrosis. A similar conclusion was done after the statistically reliable (P < 0.05) dynamics of parameters of endogenous intoxication, liperoxydation and antioxydant systems of the protection (by the level of katalase, superoxyddismutase, SH-groups, ceruloplasmine).

[PECULIARITIES OF TREATMENT VERTEBROGENIC PAIN SYNDROMES]

The results of studying the pathogenetic features of back pain at vertebrogenic of Spine, and disorders of life of patients in relation to it. Application of therapy with the standard treatment and the complex medicine of the vitamins B.

In vivo assessment of nervous fiber distribution in the intervertebral disc

This present study aims to assess in vivo the nervous fibers distribution in the intervertebral disc using diffusion tensor imaging technique. Five healthy subjects participated into the data acquisition. Fiber extraction and tracking algorithms were used. The number of fibers in L4/5 disc ranges from 314 to 679 and the mean fiber length L4/5 in disc ranges from 8.22 ± 2.36 mm to 11.24 ± 5.17 mm. This study showed the feasibility of using diffusion tensor imaging technique to detect and assess the nervous fibers in the intervertebral discs. This could be of great clinical interest for the study of the correlations between these useful characteristics with pain levels on the low back pain patients.

[AUTONOMOUS AND VERTEBRAL DYSFUNCTION IN CHILDREN]

An analysis has shown association between a vertebral dysfunction and dysfunction in the autonomic nervous system in children. Medical follow-up and electroencephalography, myographic and rheoencephalography findings has allowed concluding over clinical importance of the complaints on the back pain and changes in the cervical part of a backbone for diagnostics, prevention and treatment of autonomous dysfunction.

Increase of TRPV1-immunoreactivity in dorsal root ganglia neurons innervating the femur in a rat model of osteoporosis

PURPOSE

Transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated nonselective cation channel, which can be activated by capsaicin and other noxious stimuli. Recently, an association between bone pain and TRPV1 has been reported. However, the influence of osteoporosis on TRPV1 in the sensory system innervating the femur has not been reported.

MATERIALS AND METHODS

TRPV1-immunoreactive (ir) in dorsal root ganglia (DRG) neurons labeled with neurotracer [Fluoro-Gold (FG)] innervating the femurs of Sprague Dawley rats were examined in control, sham, and ovariectomized (OVX) rats. We evaluated osteoporosis in the femurs and compared the proportion of TRPV1-ir DRG neurons innervating femur between the 3 groups of rats.

RESULTS

OVX rats showed osteoporotic cancellous bone in the femur. FG labeled neurons were distributed from L1 to L6 DRG, but there was no significant difference in the proportion of labeled neurons between the 3 groups (p>0.05). The proportions of FG labeled TRPV1-ir DRG neurons were 1.7%, 1.7%, and 2.8% of DRG neurons innervating the femur, in control, sham-operated, and OVX rats, respectively. The proportion of TRPV1-ir neurons in DRG innervating the femur in OVX rats was significantly higher than that in control and sham-operated rats (p<0.05).

CONCLUSION

Under physiological conditions, DRG neurons innervating femurs in rats contain TRPV1. Osteoporosis increases the numbers of TRPV1-ir neurons in DRG innervating osteoporotic femurs in rats. These findings suggest that TRPV1 may have a role in sensory perception of osteoporotic femurs.

[Clinical anatomy study on autonomic nerves related to anterior approach lumbar surgery ]

OBJECTIVE

To understand the location characteristics of the lumbosacral autonomic nerve plexus and the morphological changes so as to provide the anatomic theoretical basis for the protection of autonomic nerve during the lower lumbar anterior approach operation.

METHODS

A random anatomic investigation was carried out on 19 formalin-treated adult cadavers (15 males and 4 females; aged 44-78 years, mean 64 years). The anterior median line (connection of suprasternal fossa point and the midpoint of the symphysis pubis) was determined, and the characteristics of abdominal aortic plexus (AAP), inferior mesenteric plexus (IMP), and superior hypogastric plexus (SHP) were observed. The relationship between the autonomic nerve and the anterior median line was measured and recorded.

RESULTS

APP and IMP were found to be located chiefly in front of the abdominal aorta in a reticular pattern, and the nerve fibers of the two nerve plexuses were more densely at the left side of abdominal aorta than at the right side. Superior hypogastric plexus showed more distinct main vessel variations, including 4 types. The main vessel length of the SHP was (59.38 ± 12.86) mm, and the width was (11.25 ± 2.92) mm. The main vessels of SHP were mainly located at the left side of the ventral median line (10, 52.6%) and anterior lumbar vertebra (13, 68.4%). The main vessels extended down to form the left and right hypogastric nerves.

CONCLUSION

It is applicable to expose the nerve from the right side of centrum and move the autonomic nerve and blood vessel as a whole during anterior lower lumbar operation. In this way, the dissection to separate nerve plexus is not needed, thus nerve injury can be avoided to the largest extent.

Regulation of gastric motility and blood flow during acute nociceptive stimulation of the paraspinal muscles in urethane-anaesthetised rats

The aim of this study was to examine gastric motility and blood flow during nociceptive hypertonic saline injections (HS) in paraspinal muscles of urethane-anaesthetised rats. Gastric pressure was not affected by HS in intact or vagotomised conditions. After cervical spinalisation, it was decreased by injections at T13 or L6 but not T2. Moreover, HS injections at T13 produced greater gastric pressure decreases compared with L6 and T2 and increased gastric sympathetic nerve activity. Blood pressure and gastric blood flow were decreased by T13 injections in spinal cord intact but not spinalised rats. Besides, isotonic saline injections (non-nociceptive) produced non-significant or marginal effects. These results indicate that gastric motility is decreased by nociceptive input from paraspinal muscles in spinalised rats through activation of the gastric sympathetic nerve. Although gastric blood flow was also decreased by nociceptive stimulation at T13 in spinal cord intact rats, these changes seem to depend on blood pressure.

Mechano-transduction effect of shockwaves in the treatment of lumbar facet joint pain: comparative effectiveness evaluation of shockwave therapy, steroid injections and radiofrequency medial branch neurotomy

OBJECTIVE

Lumbar facet joints (FJ) is a common source of low back pain and contributes approximmately on one third of chronic low back pain. Medial branch radiofrequency neurotomy is considered as a gold standard in the treatment of facet joint pain. Corticosteroid injections have also presented effect in FJ pain. As an interventional procedures, they carry not-negligible risk of possible complications including infection, damage to nerve root or medial branch structures. Shockwave therapy (SWT) is a non-invasive method for treatment of various musculoskeletal disorders. Its effect is based on transduction of mechanical energy, transferred to cascade of various biochemical processes in target tissue. Its efficacy was proved in the treatment of different painful conditions. The efficacy of SWT was not yet studied in FJ pain. Aim of our work was to compare the efficacy of SWT against interventional treatment procedures - radiofrequency neurotomy and corticosteroid FJ injections.

METHODS

A retrospective study was done on 62 selected patients with unilateral chronic lumbar facet pain. There were 32 women and 30 men, divided into SWT group, corticosteroid injections group radiofrequency group. Nociceptive and neuropathic pain intensity and severity of pain were measured.

RESULTS

Shockwave therapy had shown better longterm results compared to FJ injections group and little inferior efficacy compared to RMBN. We did not observe any adverse effects and complications in SWT group. Moreover, in SWT and RMBN groups, significant longterm improvement in daily activities limitation, was observed.

CONCLUSIONS

SWT appears to be a safe and perspective option in the treatment of FJ pain with negligible side effects.

[Morphological changes in the lumbar dorsal root ganglion of the domestic porcine after pulsed radiofrequency stimulation]

Pulsed radiofrequency (PRF) is a percutaneous minimal invasive procedure that can be used when conservative pain therapy methods have been ineffective. The effectiveness of PRF was demonstrated in various good quality randomized control studies, but mechanisms of action are still unclear. The aim of our study is to analyse the histological effects of PRF on the domestic porcine dorsal root ganglion (DRG), and evaluate the expression of biomarkers in gangliocytes. 3 domestic porcines were investigated. Under general anaesthesia and X-ray control, DRG PRF was performed. Four lumbar DRGs (L1, L2, L3, L4) were randomly treated. The opposite side DRGs was used as control. One month after the procedure the animal was euthanized. The lumbar region of the spine was placed in 10% formaldehyde for a month. After this fixation DRG samples were prepared for slide analysis. They were embedded in paraffin in order to obtain 3 microm thick sections, which were then cut by microtome and collected on slide glasses. Using standard immunohistochemical reactions, the materials were tinted to define biomarkers NF, GFAP, Hsp-70 expression and apoptosis by TUNEL kit. The number of cells with NF (26.0 +/- 3.0 vs 16.1 +/- 3.3; p < 0.05), GFAP (12.0 +/- 1.3 vs 3.2 +/- 0.9; p < 0.05) and Hsp-70 (10.0 +/- 1.6 vs 4.2 +/- 1.0; p < 0.05) expression, were larger in the PRF side comparing with the control side. Additionally, glial cells in spinal ganglia of both sides demonstrated immunoreactivity. The instances of apoptosis were not significantly different, in statistical terms, between the control and experimental sides (18.0 +/- 4.0 vs 20.0 +/- 4.0; p = 0.35). PRF in spinal gangliocytes of lumbar region increases neural tissue cytoskeleton factors like NF and GFAP suggesting about active regeneration processes into the cells 1 month after the procedure. Spinal gangliocytes one month after PRF treatment notably increases Hsp-70 expression suggesting about activation of cellular activity and inhibitory role reducing of oxidative stress. Similar number of apoptotic cells in spinal ganglia of lumbar region after PRF and control side suggests about inhibitory role of PRF on programmed cell death and stimulation of cell survival.

A randomised controlled trial of the efficacy of ultrasound-guided transversus abdominis plane (TAP) block in laparoscopic colorectal surgery

BACKGROUND

Optimal analgesia following laparoscopic colorectal resection is yet to be determined; however, recent studies have questioned the role of postoperative epidural anaesthesia, suggesting other analgesic modalities may be preferable. The aim of this randomised controlled trial was to assess the effect of transversus abdominis plane (TAP) blocks on opioid requirements in patients undergoing laparoscopic colorectal resection.

METHODS

After appropriate trial registration ( www.clinicaltrials.gov NCT 00830089) and local medical ethics review board approval (REC 09/H0407/10), all adult patients who were to undergo laparoscopic colorectal surgery at a single centre were randomised into the intervention group receiving bilateral TAP blocks or the control group (no TAP block). The blocks were administered prior to surgery after the induction of a standardised anaesthetic by an anaesthetist otherwise uninvolved with the case. The patient, theatre anaesthetist, surgeon, and ward staff were blinded to treatment allocation. All patients received postoperative analgesia of paracetamol and morphine as a patient-controlled analgesia (PCA). Cumulative opioid consumption and pain scores were recorded at 2, 4, 6, and 24 h postoperatively and compared between the groups as were clinical outcomes and length of stay.

RESULTS

The intervention (TAP block) group (n = 33) and the control group (n = 35) were comparable with respect to characteristics, specimen pathology, and type of procedure. The TAP block group's median cumulative morphine usage (40 mg [IQR = 25-63]) was significantly less than that of the control group (60 mg [IQR = 39-81]). Pain scores and median length of stay (LOS) were similar between the two groups.

CONCLUSION

Preoperative TAP blocks in patients undergoing laparoscopic colorectal resection reduced opioid use in the first postoperative day in this study.

[Diagnostic ideas and programs of lumbar intervetebral disc herniation]

Lumbar intervertebral disc herniation (LIDH) is one of the most common causes of lumbocrural pain with its uncertain causes, varied clinical manifestations and featuring on each individual case. Effective individualized therapy scheme depends on the correct and timely diagnosis of this disease. Many evidence indicated that the nervous symptoms and signs have higher specificity and sensitivity, has great significance to the diagnosis of LIDH but usually has polytropy among different patients or different period and conditioning of the same patient to some degree. This article systematically reviewed and analyzed the diagnostic value of specific symptoms and signs, selected physical and photographical examination methods of LIDH, and proposed that LIDH can be accurately and timely evaluated by using these diagnostic factors and ways comprehensively and systematically, this will be the helpful ideas and program to the diagnosis of this disease.

Lumbosacral intrathecal nerve roots: an anatomical study

BACKGROUND

The lumbosacral intrathecal anatomy is complex because of the density of nerve roots in the cauda equina. Space-occupying lesions, including disc herniation, trauma and tumor, within the spinal canal may compromise the nerve roots, causing severe clinical syndromes. The goal of this study is to provide spinal surgeons with a detailed anatomical description of the intrathecal nerve roots and to emphasize their clinical importance.

METHOD

Ten formalin-fixed male cadavers were studied. They were dissected with the aid of a surgical microscope, and measurements were performed.

RESULTS

The number of dorsal and ventral roots ranged from one to three. The average diameter of roots increased from L1 to S1 (0.80 mm for L1 and 4.16 for S1), respectively. Then their diameter decreased from S1 to S5 (4.16 mm for S1, 0.46 mm for S5). The largest diameter was found at S1 and the smallest at S5. The average number of rootlets per nerve root increased from L1 to S1, then decreased (3.25 for L1, 12.6 for S1, and 1.2 for S5), respectively. The greatest rootlet number was seen at S1, and the fewest were observed at S5. The average diameter of the lateral recess gradually decreased from L1 to L4 (9.1 mm for L1; 5.96 mm for L4) and then increased at L5 level (6.06 mm); however, the diameter of the nerve root increased from L1 to L5. The midpoint of distance between the superior and inferior edge of the intradural exit nerve root was 3.47 mm below the inferior edge of the superior articular process at the L1 level, while the origin of the L5 exit root was 5.75 mm above the inferior edge. The root origin gradually ascended from L1 to L5.

CONCLUSIONS

The findings of this study may be valuable for understanding lesions compressing intradural nerve roots and may be useful for intradural spinal procedures.

The use of lumbar sympathetic blockade at L4 for management of malignancy-related bladder spasms

BACKGROUND

Cancer-related bladder spasms may be a rare but severe symptom of bladder or metastatic cancer or its related treatments. Various treatments described in the literature include systemic medications, intravesical or epidural medications, or even sacral neurolectomies.

OBJECTIVE

We present 3 patients who have suffered from bladder spasm either from invasion of the bladder wall by tumor (2 patients) or from intravesical chemotherapeutic treatment.

DESIGN

Case Report.

SETTING

Cancer pain management hospital.

METHODS

For each patient, we describe the use of lumbar sympathetic block to successfully treat the bladder spasms. Sympathetic blockade was performed at the left anterolateral border of lumbar vertebra L4. We used 10 mL of local anesthetic (0.25% bupivacaine) delivered in 2 mL aliquots, each given after negative aspiration for heme. Each procedure was performed with fluoroscopic guidance (both AP and lateral views) with the use of iodine contrast (Omnipaque-180) to confirm the location of the medication and its resulting spread.

RESULTS

All 3 patients had a reduction in the frequency and intensity of spasms, with 2 out of 3 patients not having a recurrence of the spasms for up to 2 months post procedure and follow up.

LIMITATIONS

Case Report.

CONCLUSION

Lumbar sympathetic blockade could be a useful treatment for recurrent bladder spasm in the oncologic population. Based on these findings, we feel that the branches of the sympathetic nerve set at L4 may be a good target for neurolytic procedures, such as radiofrequency ablation, for long term treatment of bladder spasms. Further research is necessary to determine the efficacy of this technique for the treatment of bladder spasms in the oncologic population.

Characterization of intrathecally administered hemokinin-1-induced nociceptive behaviors in mice

Hemokinin-1 is a novel mammalian tachykinin cloned from mouse bone marrow. At present, pharmacological profile and physiological role of hemokinin-1 are still unclear. In the present study, we found that intrathecal (i.t.) administration of hemokinin-1 (0.00625-1.6 nmol) induced nociceptive responses consisting of scratching, biting and licking, which resemble substance P-induced behavioral responses in mice. The behaviors evoked by low-dose of hemokinin-1 (0.0125 nmol) were dose-dependently inhibited by i.t. co-administration of CP-99,994, a non-peptidic tachykinin NK(1) receptor antagonist, whereas high-dose of hemokinin-1 (0.1 nmol)-induced behaviors were not affected. Moreover, sendide, a peptidic tachykinin NK(1) receptor antagonist, failed to reduce the behavioral responses of both low- and high-dose of hemokinin-1. In contrast, substance P-induced behaviors were completely suppressed by both CP-99,994 and sendide. These results suggest that hemokinin-1 plays an important role in pain transmission at spinal cord. Moreover, the mechanism of hemokinin-1-induced nociceptive behaviors may be dose-dependent, and distinct from substance P-induced nociceptive behaviors.

Functional anatomy of the caudal thoracolumbar and lumbosacral spine in the horse

REASONS FOR PERFORMING STUDY

Research in spinal biomechanics and functional anatomy has advanced back pain research in man. Yet, despite the performance limiting nature of back pain in horses, there are few data for the equine spine.

OBJECTIVES

To describe aspects of functional anatomy of the equine thoracolumbar and lumbosacral (LS) spine and potential effects on performance.

METHODS

The first study investigated variations in LS vertebral formula by post mortem examination of 120 horses. Midline vertebral transection was carried out on 65 Thoroughbred (TB), 24 Standardbred (SB) and 31 other breeds. The second study investigated morphology and biomechanics of the deep stabilising epaxial muscles of 13 horses using MRI (n = 3), anatomical dissection (n = 11) and biomechanical analysis (n = 6). The spinous process angular orientation relative to the vertebral body, was analysed at vertebrae T13, T18, L3, L5, L6 and S1.

RESULTS

LS variations were found in 33.3% of the total group, 40.0% TB and 45.2% others, but 0% SB. Sacralisation of lumbar vertebra (L) 6 with LS motion between L5 and L6 occurred in 32.3% TB and 29.0% others. Five segmental multifidus fascicles were identified originating from spinous processes and vertebral laminae running craniocaudally onto the mammillary processes and lateral border of the sacrum, crossing between 1-5 intervertebral discs. Sacrocaudalis dorsalis (SCD) lateralis muscle was an extension of multifidus from L4, L5 and L6 depending on the vertebral formula whereas SCD medialis mm originated from S3. Both inserted on caudal vertebrae. Based on the location and direction of fibres, the principal action of the deep epaxial muscles was dorsoventral sagittal rotation. This action was dependent on vertebral spinous process/body orientation. We hypothesise that equine multifidus and SCD lateralis muscles act as caudal sagittal rotators of their vertebra of origin, as is the case in man, allowing dynamic stabilisation during dorsoventral motion.

CONCLUSION

Equine multifidus anatomy and function are comparable to that of man. The high prevalence of anatomical variations in the LS spine may affect maximal dorsoventral motion, the stability of the LS joint and, therefore, have consequences for athletic performance. Further studies of these structures are warranted in appropriately selected poorly performing horses.

Effects of capsaicin-induced sensory denervation on bone metabolism in adult rats

Bone metabolism has recently been revealed to be under nerve regulation. In this study, the integrity of the sensory innervation contributing to bone metabolism was examined by capsaicin-induced sensory neuron lesions. Eight-week-old male Wistar strain rats in a modeling phase of skeletal growth were divided into four groups (8 rats per group) and treated with capsaicin at one of three different doses (37.5, 75, 150 mg/kg) or vehicle, subcutaneously. Five weeks later, high-dose (150 mg/kg) capsaicin treatment had reduced trabecular bone volume (BV/TV) due to increased trabecular separation (Tb.Sp) in the proximal tibia and the modification of mechanical properties such as strength, ductility, and toughness toward increasing bone fragility in the trunk of the sixth lumbar vertebrae (L6). Moderate-dose (75 mg/kg) capsaicin treatment had no significant effect on trabecular BV/TV or bone mechanical properties but increased Tb.Sp as seen high-dose capsaicin treatment. Bone histomorphometry showed osteoclast number (Oc.N/BS) and surface (Oc.S/BS) were increased in both the moderate-dose and high-dose capsaicin treatment groups. High-dose capsaicin significantly increased the level of tartrate-resistant acid phosphatase form 5b (TRAP 5b) in plasma, a systemic bone resorption marker, but had no influence on plasma osteocalcin concentration, a bone formation marker, suggesting that capsaicin-induced sensory nerve denervation increased bone resorption but had no influence on bone formation. Low-dose (37.5mg/kg) capsaicin had no influence on bone remodeling. These results suggest that sensory nerve innervation contributes to the maintenance of trabecular bone mass and its mechanical properties by inhibiting bone resorption.

Innervation and nerve injections of the lumbar spine of the horse: a cadaveric study

REASONS FOR PERFORMING STUDY

The distal limb innervation of the horse has been studied extensively to allow use of local anaesthetic techniques to detect the origin of pain in lameness. However, the innervation of the lumbar spine has so far been poorly described and a more precise description may assist clinicians to localise back pain in the horse.

OBJECTIVES

To gain better knowledge of the innervation of the lumbar spine and identify salient anatomical features that might be used for diagnostic and therapeutic ultrasound guided injections.

METHODS

The spines of 8 mature horses were dissected. Branches of the dorsal rami were followed and their anatomical relationship, with articular facets, interspinous structures and muscles, noted. The spines of 3 other horses were sectioned transversely and dissected to identify ultrasonographic landmarks of the nerves. Six other spines were used to assess the accuracy of ultrasound guided injections of the nerves with blue dye.

RESULTS

Gross dissections confirmed the dual segmental innervation of the articular facets. Each lumbar articular facet of 2 lumbar vertebrae was innervated by the medial branch of the dorsal ramus exiting from the intervertebral foramen between those vertebrae, but also by the branch originating of the dorsal ramus cranial to it. The medial branch divided into 2 nerves before exiting the intertransverse space and has salient anatomical landmarks which could be identified ultrasonographically. The ultrasound guided injection technique appeared to be of an accuracy that would be clinically useful.

CONCLUSION

The results identified that the salient anatomical features of the medial branch of the dorsal ramus, as described in the present study, can be used as landmarks for reliable ultrasound-guided injection.

POTENTIAL RELEVANCE

This study has a clear clinical relevance for development of diagnostic and therapeutic injection techniques of the lumbar spine in the horse.

Accuracy of diagnostic lumbar facet joint nerve blocks: a 2-year follow-up of 152 patients diagnosed with controlled diagnostic blocks

BACKGROUND

Lumbar facet joint pain is diagnosed by controlled diagnostic blocks. The accuracy of controlled diagnostic blocks has been demonstrated in multiple studies and confirmed in systematic reviews. Controlled diagnostic studies have shown an overall prevalence of lumbar facet joint pain in 31% of the patients with chronic low back pain without disc displacement or radiculitis, with an overall false-positive rate of 30% using a single diagnostic block.

STUDY DESIGN

An observational report of outcomes assessment.

SETTING

An interventional pain management practice setting in the United States.

OBJECTIVE

To determine the accuracy of controlled diagnostic blocks in managing lumbar facet joint pain at the end of 2 years.

METHODS

This study included 152 patients diagnosed with lumbar facet joint pain using controlled diagnostic blocks. The inclusion criteria was based on a positive response to diagnostic controlled comparative local anesthetic lumbar facet joint blocks. The treatment included therapeutic lumbar facet joint nerve blocks.

OUTCOME MEASURES

The sustained diagnosis of lumbar facet joint pain at the end of one year and 2 years based on pain relief and functional status improvement.

RESULTS

At the end of one year 93% of the patients and at the end of 2 years 89.5% of the patients were considered to have lumbar facet joint pain.

LIMITATIONS

The study is limited by its observational nature.

CONCLUSION

Controlled diagnostic lumbar facet joint nerve blocks are valid utilizing the criteria of 80% pain relief and the ability to perform previously painful movements, with sustained diagnosis of lumbar facet joint pain in at least 89.5% of the patients at the end of a 2-year follow-up period.

Presence of NGF and its receptor TrkA in degenerative lumbar facet joint specimens

In a preliminary study, the recurrent presence of nervous terminations was demonstrated with optical microscopy in several slides of degenerative lumbar facet joints and surrounding soft tissues. The purpose of this study was to prove the presence of NGF (nerve growth factor) and its receptor TrkA (tyrosine kinase receptor) with immunofluorescence. The peri/articular tissues were harvested from the lumbar facet joints of ten patients surgically treated for degenerative diseases. There were seven females (one bilateral) and two males whose mean age at surgery was 72 years (range, 67-80 years). The affected levels were L3-L4 in two cases and L4-L5 in seven cases (one bilateral). All specimens were fixed in formalin, dehydrated and enclosed in paraffin. From each specimen, four slides were obtained. Two slides were employed for the search of NGF: one was treated with specific antibodies and marked with FITC (fluorescein isothiocyanate conjugated), and the second slide was for control purposes. It was exposed to FITC, but without prior exposure to the specific antibody. The same procedure was repeated to obtain on two more slides, to repeat the search for Trka with specific antibodies. All the slides were finally studied on a fluoromicroscope. The analysis of these specimens revealed the presence of the neurotrophin (NGF) and its own receptor (TrkA) in all cases: the immunohistochemical reaction between the specimens and the specific antibodies marked with FITC was seen under fluoromicroscopy, but in none of the control cases treated with FITC only. NGF is released by mastocytes, fibroblasts and other cell types involved in the inflammatory processes. The level of peripheral NGF is increased in inflammatory processes, while the administration of exogenous NGF has a hyperalgesic effect on rats and produces muscular pain in humans. Furthermore, NGF produces hypersensitization to heat stimulation in humans and mammals in general. There is considerable evidence showing that the system constituted by the NGF and its high-affinity receptor TrkA plays a fundamental role in the molecular processes underlying the main forms of "persistent" pain. This indicates a possible therapeutic area for the antibodies that could block the NGF/TrkA system, in order to modulate the frequency and the duration of the action potential of nociceptive neurons during chronic inflammation. This study demonstrated the presence of NGF and TrkA in specimens collected from degenerative facet joints, suggesting that specific molecules could be used in order to modulate chronic pain in patients with degenerative lumbar spine.

Systematic review of lumbar discography as a diagnostic test for chronic low back pain

BACKGROUND

The intervertebral disc has been implicated as an etiology of chronic lumbar spine pain based on clinical, basic science, and epidemiological research. However, there is lack of consensus regarding the diagnosis and treatment of intervertebral disc disorders. Based on controlled evaluations, the lumbar intervertebral discs have been shown to be sources of chronic back pain without disc herniation in 26% to 39%. Lumbar provocation discography, which includes disc stimulation and morphological evaluation, is often used to distinguish a painful disc from other potential sources of pain. Despite the extensive literature, controversy continues about provocation lumbar discography.

STUDY DESIGN

A systematic review of the lumbar provocation discography literature.

OBJECTIVES

To systematically assess the diagnostic accuracy of lumbar discography.

METHODS

A systematic review of the literature was performed to assess the diagnostic accuracy of lumbar discography with respect to chronic low back pain. Study inclusion/exclusion criteria were based on International Association for the Study of Pain (IASP) standards with pain provocation and determination of controlled discs. Selected studies were then subjected to a rating instrument for diagnostic accuracy studies. Specific data were then culled from these studies and tabulated. Quality of evidence was assessed using modified Agency for Healthcare Research and Quality (AHRQ) diagnostic accuracy evaluation. Studies meeting methodologic quality criteria scores of 50 or higher were included in the assessment of the level of evidence. Qualitative analysis was conducted using 5 levels of evidence, ranging from Level I to III, with 3 subcategories in Level II. The rating scheme was modified to evaluate the diagnostic accuracy.

RESULTS

Based on a modified U.S. Preventive Services Task Force (USPSTF) level of evidence criteria, this systematic review indicates the strength of evidence as Level II-2 for the diagnostic accuracy of lumbar provocation discography utilizing IASP criteria.

LIMITATIONS

Limitations include a paucity of literature, poor methodologic quality, and very few studies performed utilizing IASP criteria.

CONCLUSION

Based on the current systematic review, lumbar provocation discography performed according to the IASP criteria with control disc (s) with minimum pain intensity of 7 of 10, or at least 70% reproduction of worst pain (i.e. worst spontaneous pain of 7 = 7 x 70% = 5) may be a useful tool for evaluating chronic lumbar discogenic pain. Discography is an important imaging and pain evaluation tool in identifying a subset of patients with chronic low back pain secondary to intervertebral disc disorders.

Ultrasound guided, painful electrical stimulation of lumbar facet joint structures: an experimental model of acute low back pain

Quantitative sensory testing has indicated generalized muscle hyperalgesia in patients with chronic low back pain. The temporal development of such hyperalgesia is not well understood. The aim of the present study was to demonstrate whether generalized muscle hyperalgesia can develop within minutes of acute low back pain using a new experimental model of lumbar facet joint pain. Thirteen healthy volunteers were included and baseline pressure pain thresholds were assessed at eight separate sites, outside the area of evoked low back and referred pain. Using ultrasonography, two electrode needles were placed either side of a lumbar facet joint (right L3-4) and used to induce experimental low back pain for 10 min with continuous stimulation. Thresholds, stimulus-response relationships, distribution and quality of the electrically induced pain were recorded. Electrical facet joint stimulation induced low back pain and pain referral into the anterior leg, ipsilaterally, proximal to the knee, similar to what is observed clinically. Pressure pain thresholds did not change significantly before, during and after facet joint stimulation. In conclusion, we describe a novel model of acute experimental low back pain and demonstrate that generalized hyperalgesia did not develop within minutes of acute low back pain.

Radiofrequency cannula with active tip radio-opaque marker: image analysis for facet, gray ramus, and dorsal root ganglion techniques

BACKGROUND

Radiofrequency neurolysis is a common technique used in the treatment of chronic pain, particularly facet (zygapophyseal joint) arthralgia. A needle-like cannula is insulated except for the exposed active tip, which is positioned as parallel and adjacent as possible to the targeted nerve branch. Via an inserted probe connected to a radiofrequency generator, energy flowing from the tip of the cannula creates a heat lesion in the 80 - 85 degree Celsius range mostly about the length of the exposed active tip and in proportion to the diameter of the probe. The common active tip lengths used for neurolysis are 5mm or 10mm. The cannulae are FDA approved. The manufacturer advises physicians not to bend or otherwise modify a cannula prior to use. The cannulae are available straight or bent, sharp and blunt. The technique is guided under C-arm fluoroscopy. X-rays passing through the patient demonstrate in 2 dimensions the projected relative radio-opaque bony landmarks and the metallic cannula. Most currently available cannulae are uniform in their radio-opacity from tip to hub. The physician must make an educated guess as to the portion of the cannula that will be making the lesion in relationship to the bony landmark.

OBJECTIVE

A new radiofrequency cannula with a radio-opaque marker (ROC) delineates the proximal end of the active tip. The cannula was used in a phantom model. Images were reproduced with explanation of the potential advantage of the new device.

RESULT

The marker on the new cannula was visible and did help delineate the active tip as well as its orientation. It was also helpful in making sequential lesions at the same nerve using a "tip to tail" repositioning technique.

CONCLUSION

The ROC did represent an improvement over standard cannulae to optimize visualization of cannula and thus lesion placement using a phantom model. The applications described were only for conventional or "hot" RF.

Electric efficiency of the erector spinae in high performance amateur tennis players

AIM

The aim of the paper was to evaluate neuromuscular activity patterns of the lumbar erector spinae during isometric voluntary maximum trunk extension and how this could be influenced through a back exercise home program in high performance amateur tennis players.

METHODS

Experimental longitudinal study of the lower back in a clinical setting. Seventy high performance amateur tennis players underwent isometric trunk extension tests in a specially built apparatus with simultaneous surface electromyography (EMG) recording from right and left lumbar erector spinae. Imbalance quotients were calculated using Electric Efficiency measures. Isometric and electromyographic changes were reviewed after a 7-week daily home program of back exercise.

RESULTS

Neuromuscular imbalance of the lumbar erector spinae associated with reduced Electric Efficiency, closely related to handedness was observed amongst tennis athletes at the start of the study. After a 7-week back exercise home program, lumbar neuromuscular imbalances were evened out and the Electric Efficiency of the erector spinae improved significantly at lumbar level L2 and L4. No significant difference was measured in maximal isometric trunk extension strength.

CONCLUSION

The asymmetric trunk loading caused by tennis specific biomechanics with trunk hyperextension motions and trunk rotation seems to induce imbalanced muscle activity patterns of the lumbar erector spinae. A home program of back exercises for tennis players can help to compensate for these imbalances, improves Electric Efficiency patterns of the erector spinae and should therefore be integrated in the daily training routine of high performance tennis players.

The nerve supply of the lumbar intervertebral disc

The anatomical studies, basic to our understanding of lumbar spine innervation through the sinu-vertebral nerves, are reviewed. Research in the 1980s suggested that pain sensation was conducted in part via the sympathetic system. These sensory pathways have now been clarified using sophisticated experimental and histochemical techniques confirming a dual pattern. One route enters the adjacent dorsal root segmentally, whereas the other supply is non-segmental ascending through the paravertebral sympathetic chain with re-entry through the thoracolumbar white rami communicantes. Sensory nerve endings in the degenerative lumbar disc penetrate deep into the disrupted nucleus pulposus, insensitive in the normal lumbar spine. Complex as well as free nerve endings would appear to contribute to pain transmission. The nature and mechanism of discogenic pain is still speculative but there is growing evidence to support a 'visceral pain' hypothesis, unique in the muscloskeletal system. This mechanism is open to 'peripheral sensitisation' and possibly 'central sensitisation' as a potential cause of chronic back pain.

Preliminary morphological evidence that vertebral hypomobility induces synaptic plasticity in the spinal cord

OBJECTIVE

A widely accepted theoretical model suggests that vertebral hypomobility can cause pain and abnormal spinal mechanics because of changes in sensory input from spinal and paraspinal tissues. The purpose of this pilot study was 3-fold: (1) to make a preliminary determination if chronic vertebral hypomobility at L4 through L6 in the rat would affect synaptic density and/or morphology in the superficial dorsal horn of the L2 spinal cord level, (2) to identify relevant outcome variables for future studies, and (3) to obtain preliminary data that would permit estimating an appropriate sample size for future studies.

METHODS

Using an established rat model, we fixed 3 contiguous lumbar segments (L4-L6) for 8 weeks with a specially engineered vertebral fixation device. Electron micrographs were obtained from 2 animals from the experimental (fixed) group and each of 3 control groups (no surgery, surgery but no devices implanted, and devices implanted but not fixed). Synapses were randomly selected using a stereological approach and were analyzed for symmetry, curvature, type of postsynaptic profile, and perforations. The synaptic density was also estimated.

RESULTS

There was increased synaptic density and percentage of positively curved synapses in the dorsal horn of experimental animals as compared with controls. Experimental animals had a lower percentage of axospinous synapses, with a concomitant increase in the percentage of synapses on dendritic shafts.

CONCLUSIONS

These preliminary data suggest for the first time that chronic vertebral hypomobility at L4 through L6 in the rat affects synaptic density and morphology in the superficial dorsal horn of the L2 spinal cord level. More definitive studies are warranted, and the biologic significance of these finding should be investigated.

Alternative denervation using laser irradiation in lumbar facet syndrome

BACKGROUND AND OBJECTIVE

Facet syndrome is persistent low back pain that might be treated with some surgical interventions. The target of surgical techniques is the transverse process bases where the medial nerve branches innervated the facet. However, highly variable success rates have been demonstrated in different series.

STUDY DESIGN/MATERIALS AND METHODS

We carried out laser denervation to the dorsal surface of the facet capsule, where it is richly innervated with medial nerve branches.

RESULTS

One year after laser denervation, 17 patients (81%) experienced complete or greater than 70% pain reduction in all 21 patients. Among the six patients who had previously undergone spinal surgery, two (33.3%) experienced successful pain relief. Overall, in four patients (19%), the response to laser denervation at 1-year follow-ups was not successful.

CONCLUSION

The dorsal surface of the facet capsule might be a more preferable target for facet denervation.

Sensory innervation of lumbar vertebral bodies in rats

STUDY DESIGN

Using a retrograde neurotracing method with Fluoro-Gold (FG), the level at which dorsal root ganglions (DRGs) innervate the L2 and L5 vertebral bodies and the innervation pathways were investigated in rats.

OBJECTIVE

To clarify the levels at which DRGs innervate the lumbar vertebral bodies and to determine the pathways from the L2 and L5 vertebral bodies to DRGs.

SUMMARY OF BACKGROUND DATA

Elderly patients with osteoporosis sometimes experience lumbar vertebral fracture and may also feel diffuse nonlocalized pain in the back, lateral portion of the trunk, and area surrounding the iliac crest. However, the pattern of sensory innervation of vertebral bodies remains unclear.

METHODS

Forty female Sprague-Dawley rats were used. FG crystals were applied to the L2 (L2 vertebra group) or L5 (L5 vertebra group) vertebral bodies via an anterior approach, and numbers of labeled neurons in DRGs from T10 to L6 were counted. To determine sensory pathways, bilateral sympathectomy was performed.

RESULTS

In nonsympathectomy animals, FG-labeled neurons were present in DRGs from T11 through L3 in the L2 vertebra group and from T13 through L6 in the L5 vertebra group. The number of labeled neurons following sympathectomy was not significantly different in L1, L2, and L3 DRGs in the L2 vertebra group or in L3, L4, L5, and L6 DRGs in the L5 vertebra group from those in nonsympathectomy animals. In contrast, fewer labeled DRG neurons were present in sympathectomy animals at T11, T12, and T13 in the L2 vertebra group, and at T13, L1, and L2 in the L5 vertebra group than in nonsympathectomy animals (P < 0.01).

CONCLUSION

Sensory nerve fibers in the L2 and L5 vertebral bodies are derived from the T11-L3 and T13-L6 DRGs, respectively. Some sensory nerves from the L2 and L5 vertebral bodies enter the paravertebral sympathetic trunks and reach the DRGs at multisegmental levels. The present findings regarding multisegmental innervation to vertebral bodies may explain the diffuse pain that originates within osteoporotic vertebral fractures in elderly patients.

Thoracic and lumbar paravertebral blocks for outpatient lithotripsy

Paravertebral nerve block has been used for a variety of surgical procedures to provide unilateral anesthesia and postoperative analgesia. We report the successful application of this regional anesthesia modality for outpatient lithotripsy. Preoperatively, thoracic and lumbar paravertebral nerve blocks with 0.5% ropivacaine were placed with ultrasound and nerve stimulator guidance for two patients with ureteral calculi. One patient scheduled for cystoscopy and ureteroscopy with laser lithotripsy received general anesthesia intraoperatively. The second patient underwent extracorporeal shock wave lithotripsy with propofol intravenous sedation. Postoperatively, both patients reported pain scores of zero (Visual Analog Scale) for 24 hours and required no opioid rescue analgesia.

Characteristics of Sensory Dorsal Root Ganglia Neurons Innervating the Lumbar Vertebral Body in Rats

Characteristics of sensory dorsal root ganglia (DRG) neurons innervating the L5 vertebral body were investigated in rats by using a retrograde neurotransport method, lectin affinity- and immuno-histochemistry to further elucidate the causes of diffuse pain suffered by some elderly patients in their back, lateral trunk, and iliac crest, after lumbar osteoporotic vertebral fracture. We used calcitonin gene-related peptide (CGRP) as a marker of small peptide-containing neurons and the glycoprotein binding the isolectin from Griffonia simplicifolia (IB4) as a marker of small non-peptide-containing neurons. Neurons innervating the L5 vertebral bodies, retrogradely labeled with fluoro-gold (FG), were distributed throughout DRGs from T13 to L6. The proportion of CGRP-immunoreactive (IR) FG-labeled neurons was 32%. The proportion of IB4-binding FG-labeled neurons was significantly smaller, at 4%. Other neurons that were non-CGRP-IR and non-IB4-binding were mostly large neurons, and they may transmit proprioception from vertebral bodies. Most neurons transmitting pain are CGRP-IR peptide-containing neurons. They may have a more significant role in pain sensation in the vertebral bodies as peptidergic DRG neurons.

PERSPECTIVE

This article shows that vertebral bodies are innervated by CGRP-IR neurons. CGRP-IR neurons may play a role in pain sensation through peptidergic DRG neurons. These findings contribute to an understanding of pain associated with the vertebral body such as tumor, infection, or osteoporotic fracture.

Pathogenesis, diagnosis, and treatment of lumbar zygapophysial (facet) joint pain

Lumbar zygapophysial joint arthropathy is a challenging condition affecting up to 15% of patients with chronic low back pain. The onset of lumbar facet joint pain is usually insidious, with predisposing factors including spondylolisthesis, degenerative disc pathology, and old age. Despite previous reports of a "facet syndrome," the existing literature does not support the use of historic or physical examination findings to diagnose lumbar zygapophysial joint pain. The most accepted method for diagnosing pain arising from the lumbar facet joints is with low-volume intraarticular or medial branch blocks, both of which are associated with high false-positive rates. Standard treatment modalities for lumbar zygapophysial joint pain include intraarticular steroid injections and radiofrequency denervation of the medial branches innervating the joints, but the evidence supporting both of these is conflicting. In this article, the authors provide a comprehensive review of the anatomy, biomechanics, and function of the lumbar zygapophysial joints, along with a systematic analysis of the diagnosis and treatment of facet joint pain.

Up-regulation of p55 TNF alpha-receptor in dorsal root ganglia neurons following lumbar facet joint injury in rats

The rat L5/6 facet joint is multisegmentally innervated from the L1 to L6 dorsal root ganglia (DRG). Tumor necrosis factor (TNF) is a known mediator of inflammation. It has been reported that satellite cells are activated, produce TNF and surround DRG neurons innervating L5/6 facet joints after facet injury. In the current study, changes in TNF receptor (p55) expression in DRG neurons innervating the L5/6 facet joint following facet joint injury were investigated in rats using a retrograde neurotransport method followed by immunohistochemistry. Twenty rats were used for this study. Two crystals of Fluorogold (FG; neurotracer) were applied into the L5/6 facet joint. Seven days after surgery, the dorsal portion of the capsule was cut in the injured group (injured group n = 10). No injury was performed in the non-injured group (n = 10). Fourteen days after the first application of FG, bilateral DRGs from T13 to L6 levels were resected and sectioned. They were subsequently processed for p55 immunohistochemistry. The number of FG labeled neurons and number of FG labeled p55-immunoreactive (IR) neurons were counted. FG labeled DRG neurons innervating the L5/6 facet joint were distributed from ipsilateral L1 to L6 levels. Of FG labeled neurons, the ratio of DRG neurons immunoreactive for p55 in the injured group (50%) was significantly higher than that in the non-injured group (13%). The ratio of p55-IR neurons of FG labeled DRG neurons was significantly higher in total L1 and L2 DRGs than that in total L3, 4, 5 and 6 DRGs in the injured group (L1 and 2 DRG, 67%; L3, 4, 5 and 6 DRG, 37%, percentages of the total number of p55-IR neurons at L1 and L2 level or L3-6 level/the total number of FG-labeled neurons at L1 and L2 level or L3-6 level). These data suggest that up-regulation of p55 in DRG neurons may be involved in the sensory transmission from facet joint injury. Regulation of p55 in DRG neurons innervating the facet joint was different between upper DRG innervated via the paravertebral sympathetic trunks and lower DRG innervated via other direct routes.

[Anatomical study of human lumbar spine innervation]

OBJECTIVE

To explore the detailed innervation of the lumbar spine of humans.

METHODS

Six adult cadavers fixed in a solution containing 10% formalin were investigated under a stereomicroscope. The lumbar spine, together with the abdominal aorta, inferior vena cava and psoas muscle, was extracted. The dissection was focused on various patterns of rami communicantes (RC), including superficial oblique rami (SOR) and deep transverse rami (DTR), and their relationship to the psoas major muscle, the minute nerve supply of the anterior and posterior longitudinal ligaments, vertebral bodies and the intervertebral discs.

RESULTS

Two types of RC were observed: SOR and DTR. SOR ran obliquely between the superficial heads of the psoas major muscle, connecting the sympathetic trunk and T12-L2 spinal nerves non-segmentally. DTR, running along the lumbar arteries and veins, were distributed segmentally, close to the vertebral bodies. On the anterior aspect of the lumbar spine, the anterior longitudinal ligaments received branches from the sympathetic trunk and splanchnic nerves non-segmentally. On the lateral side of the lumbar spine, the vertebral bodies and the intervertebral discs received branches from the DTR and ventral rami segmentally, branches from the sympathetic trunk, and, in the upper lumbar region, SOR non-segmentally. Within the vertebral canal, the posterior aspect of the intervertebral discs and the posterior longitudinal ligaments received the sinu-vertebral nerves originating from DTR.

CONCLUSION

Exist two different types of innervation in the lumbar vertebrae: one originating directly from the spinal nerve segmentally, and one reaching the vertebral body and intervertebral disc via the sympathetic nerves non-segmentally. Therefore, sympathetic nerves are involved in the innervation of the spinal column and intervertebral disc and are likely involved in discogenic low back pain.

Preureteric inferior vena cava with possible rudiment of the proper inferior vena cava

A right single preureteric inferior vena cava (IVC) was found in the cadaver of a 77-year-old Japanese male during a student dissection course at Kumamoto University School of Medicine in 2003. The ureter emerged from the lower end of the hilum of the right kidney at the second lumbar vertebral level. It ran inferomedially to pass behind the IVC, and turned inferolaterally to cross the vein superficially at the level of the third to the fourth lumbar vertebrae. Then, the ureter was situated to the right of the IVC, and descended ordinarily. The second lumbar vein of each side united bilaterally, as did the third lumbar veins. The common stem of the second lumbar veins drained into the left side of the IVC posterolaterally at the level of the second intervertebral disc, and the third common stem opened into the left border of the IVC at the fourth lumbar vertebral level. The ureter hooked around the IVC between the openings of those common stems. There was a small continuation (0.2 mm in diameter) between the left second lumbar and the right third lumbar veins along the vertebral column slightly right of the midline. It passed superficial to the right third lumbar artery, as did the IVC. The right testicular vein opened into the IVC at the level of the lower end of the third lumbar vertebral body. Generally, the level of the opening of the gonadal vein corresponds to the level of the caudal end of the remaining subcardinal vein, but it is lower than usual in this case. Furthermore, the segment from the confluence of the common iliac veins to the common trunk of the third lumbar veins, and to the small continuation can be regarded as the proper IVC, and the part where the ureter hooks around it may have derived from the anastomosis between the common trunk of the third lumbar veins and the subcardinal vein.

Clinical predictors of success and failure for lumbar facet radiofrequency denervation

OBJECTIVE

To determine the clinical factors associated with the success and failure of radiofrequency denervation of the lumbar facet joints.

METHODS

Clinical data were garnered from 3 academic medical centers on 192 patients with low back pain who underwent radiofrequency denervation after a positive response to diagnostic blocks. Success was defined as >/=50% pain relief lasting at least 6 months. Factors evaluated for their association with outcome included duration of pain, opioid use, symptom location, paraspinal tenderness, pain exacerbated by extension/rotation (ie, facet loading), MRI abnormalities, diabetes, smoking, scoliosis, obesity, prior surgery and levels treated.

RESULTS

The only factor associated with a successful outcome was paraspinal tenderness. Variables that correlated with treatment failure were 'facet loading,' long duration of pain, and previous back surgery.

CONCLUSIONS

It is counterproductive to use 'facet loading' as the sole basis for choosing patients for facet interventions. In patients at high risk for treatment failure, taking additional steps to reduce the rate of false-positive screening blocks may improve outcomes.