Management of chronic low back pain: rationales, principles, and targets of imaging-guided spinal injections

Selective MR neurography-guided lumbosacral plexus perineural injections: techniques, targets, and territories

The T12 to S4 spinal nerves form the lumbosacral plexus in the retroperitoneum, providing sensory and motor innervation to the pelvis and lower extremities. The lumbosacral plexus has a wide range of anatomic variations and interchange of fibers between nerve anastomoses. Neuropathies of the lumbosacral plexus cause a broad spectrum of complex pelvic and lower extremity pain syndromes, which can be challenging to diagnose and treat successfully. In their workup, selective nerve blocks are employed to test the hypothesis that a lumbosacral plexus nerve contributes to a suspected pelvic and extremity pain syndrome, whereas therapeutic perineural injections aim to alleviate pain and paresthesia symptoms. While the sciatic and femoral nerves are large in caliber, the iliohypogastric and ilioinguinal, genitofemoral, lateral femoral cutaneous, anterior femoral cutaneous, posterior femoral cutaneous, obturator, and pudendal nerves are small, measuring a few millimeters in diameter and have a wide range of anatomic variants. Due to their minuteness, direct visualization of the smaller lumbosacral plexus branches can be difficult during selective nerve blocks, particularly in deeper pelvic locations or larger patients. In this setting, the high spatial and contrast resolution of interventional MR neurography guidance benefits nerve visualization and targeting, needle placement, and visualization of perineural injectant distribution, providing a highly accurate alternative to more commonly used ultrasonography, fluoroscopy, and computed tomography guidance for perineural injections. This article offers a practical guide for MR neurography-guided lumbosacral plexus perineural injections, including interventional setup, pulse sequence protocols, lumbosacral plexus MR neurography anatomy, anatomic variations, and injection targets.

Defining the Patient with Lumbar Discogenic Pain: Real-World Implications for Diagnosis and Effective Clinical Management

There is an enormous body of literature that has identified the intervertebral disc as a potent pain generator. However, with regard to lumbar degenerative disc disease, the specific diagnostic criteria lack clarity and fail to capture the primary components which include axial midline low back pain with or without non-radicular/non-sciatic referred leg pain in a sclerotomal distribution. In fact, there is no specific ICD-10-CM diagnostic code to classify and define discogenic pain as a unique source of pain distinct from other recognized sources of chronic low back pain including facetogenic, neurocompressive including herniation and/or stenosis, sacroiliac, vertebrogenic, and psychogenic. All of these other sources have well-defined ICD-10-CM codes. Corresponding codes for discogenic pain remain absent from the diagnostic coding vernacular. The International Society for the Advancement of Spine Surgery (ISASS) has proposed a modernization of ICD-10-CM codes to specifically define pain associated with lumbar and lumbosacral degenerative disc disease. The proposed codes would also allow the pain to be characterized by location: lumbar region only, leg only, or both. Successful implementation of these codes would benefit both physicians and payers in distinguishing, tracking, and improving algorithms and treatments for discogenic pain associated with intervertebral disc degeneration.

MRI-guided sacroiliac joint injections in children and adults: current practice and future developments

Common etiologies of low back pain include degenerative arthrosis and inflammatory arthropathy of the sacroiliac joints. The diagnostic workup revolves around identifying and confirming the sacroiliac joints as a pain generator. Diagnostic sacroiliac joint injections often serve as functional additions to the diagnostic workup through eliciting a pain response that tests the hypothesis that the sacroiliac joints do or do not contribute to the patient's pain syndrome. Therapeutic sacroiliac joint injections aim to provide medium- to long-term relief of symptoms and reduce inflammatory activity and, ultimately, irreversible structural damage. Ultrasonography, fluoroscopy, computed tomography, and magnetic resonance imaging (MRI) may be used to guide sacroiliac joint injections. The populations that may benefit most from MRI-guided sacroiliac joint procedures include children, adolescents, adults of childbearing age, and patients receiving serial injections due to the ability of interventional MRI to avoid radiation exposure. Most clinical wide-bore MRI systems can be used for MRI-guided sacroiliac joint injections. Turbo spin echo pulse sequences optimized for interventional needle display visualize the needle tip with an error margin of < 1 mm or less. Published success rates of intra-articular sacroiliac joint drug delivery with MRI guidance range between 87 and 100%. The time required for MR-guided sacroiliac joint injections in adults range between 23-35 min and 40 min in children. In this article, we describe techniques for MRI-guided sacroiliac joint injections, share our practice of incorporating interventional MRI in the care of patients with sacroiliac joint mediated pain, discuss the rationales, benefits, and limitations of interventional MRI, and conclude with future developments.

The Benefit of Epidural Transforaminal Injection of Ozone in Comparison With Transforaminal Steroids Injection in the Management of Chronic Low Back Pain in Lebanese Population: One-Year Retrospective Study

Background Chronic low back pain (CLBP) is one of the most common complaints affecting the population worldwide including in Lebanon. Until 15 years ago, surgery was the treatment of choice. However, conservative measures are now preferred because of the large number of post-surgical complications, in addition to the many conditions where surgery cannot be performed. Objective The aim of our study is to determine the effectiveness of transformational epidural injection of ozone (TFEOI) in the management of CLBP among the Lebanese population in the Nabatieh area in comparison with patients who received transformational epidural steroid injection (TFESI). Methods A one-year (2016-2017) retrospective study where 100 patients with CLBP were selected from two hospitals (Alnajdah, and Ragheb Harb hospitals) and divided into two groups. Fifty patients were treated with Ozone injections while the other 50 were treated with steroid injections. For each patient, we recorded the type of pain, irradiation, paresthesia, and the type of injection given (steroid or Ozone). We used the patients' files and contacted them via phone calls. The results of this study were reached based on Vas Score and Mac Nab criteria which are subjective questionnaires. Results The study showed that the TFESI was effective for a short duration (86% of results were excellent and good after one month of injection, but they decreased to 16% after six months). On the other hand, TFEOI was effective over both short and long duration (82% excellent and good after one month, 64% excellent and good after six months). Conclusion Results from this study provide that ozone injection has high benefits in the management of CLBP in the Lebanese population.

Transforaminal Epidural Steroid Injection for Patients with Lumbosacral Disc Herniation in the Absence of Spine Magnetic Resonance Imaging - Is Better Really the Enemy of the Best?

Purpose

This study aimed to evaluate the effect of transforaminal epidural steroid injection (TFESI) in patients with lumbosacral disc herniation by comparing its effect between those diagnosed by clinical evaluation and plain radiography only (X-ray group) and those by additional magnetic resonance imaging (MRI) (MRI group). Additionally, we investigated the accuracy of the preliminary clinical assumption in the X-ray group using confirmative post-injection MRI.

Patients and Methods

We retrospectively recruited 367 patients with back and radicular pain due to lumbosacral disc herniation from a single pain clinic. Among them, 201 and 166 patients were categorized into the X-ray and MRI groups, respectively. In the X-ray group, the pathological level assumed initially by clinical evaluation and plain radiography concurred with that confirmed later on post-injection MRI in 139 patients (corresponding group); the remaining 62 patients lacked this concurrence (non-corresponding group). The NRS scores and Macnab criteria results were compared between the X-ray and MRI groups as well as the corresponding and non-corresponding groups.

Results

Both the X-ray and MRI groups showed significant reductions in the NRS scores at 2 and 10 weeks post-injection when compared with the pretreatment scores. However, no significant difference was noted between the groups in terms of the magnitude of clinical improvement assessed by successful reduction in the NRS or Macnab scores. Furthermore, similar results were obtained in the comparison between the corresponding and non-corresponding groups of the X-ray group.

Conclusion

TFESI guarantees favorable clinical outcomes even in the absence of confirmative MRI in patients with back and radicular pain. The preemptive application of this procedure could be prioritized and justified in patients suspected of lumbosacral disc herniation based on clinical evaluation and plain radiography only without the preceding MRI verification.

Observer agreement in the choice of lumbar spine injection for pain management

BACKGROUND AND PURPOSE

Lumbar spine MRI can help guide the choice of corticosteroid injection in pain management. We investigated whether patient-reported symptom information from a questionnaire could improve agreement in the choice of type, level, and side of injection.

MATERIALS AND METHODS

In this prospective observational study, 120 patients (median age 64, 70 men) were recruited from patients referred for pain management. After informed consent, they completed electronic questionnaires that obtained symptom information for later use during MRI reviews. In 3 research arms, 6 radiologists chose injections that would ideally deliver corticosteroid to the presumed sources of pain in (1) MRI studies reviewed with symptom information from questionnaires, (2) MRI studies reviewed without symptom information, and (3) MRI reports. Blinded to questionnaire results, radiologists providing clinical care and interviewing patients chose ideal therapeutic injections to establish reference standards. Injections were categorized by type, level, and side and compared using percent agreement and kappa statistics. Interreading agreement was analyzed.

RESULTS

Compared to the reference standard, kappa agreements for injection types, levels, and sides were almost perfect when MRIs were reviewed knowing symptoms (0.85-0.93), fair without symptoms (0.23-0.35) (all P < .001) and fair in MRI reports (0.24-0.36) (all P < .001). Interreading kappa agreements were almost perfect knowing symptoms (0.82-0.90), but only moderate without symptoms (0.42-0.49) (all P < .001).

CONCLUSIONS

Radiologists reviewing lumbar spine MRI converged on the type, level, and side of ideal therapeutic injection whether they obtained symptom information from direct patient interview or electronic questionnaire. Observer agreement was significantly lower without symptom information.

Fully Actuated Body-Mounted Robotic System for MRI-Guided Lower Back Pain Injections: Initial Phantom and Cadaver Studies

This paper reports the improved design, system integration, and initial experimental evaluation of a fully actuated body-mounted robotic system for real-time MRI-guided lower back pain injections. The 6-DOF robot is composed of a 4-DOF needle alignment module and a 2-DOF remotely actuated needle driver module, which together provide a fully actuated manipulator that can operate inside the scanner bore during imaging. The system minimizes the need to move the patient in and out of the scanner during a procedure, and thus may shorten the procedure time and streamline the clinical workflow. The robot is devised with a compact and lightweight structure that can be attached directly to the patient's lower back via straps. This approach minimizes the effect of patient motion by allowing the robot to move with the patient. The robot is integrated with an image-based surgical planning module. A dedicated clinical workflow is proposed for robot-assisted lower back pain injections under real-time MRI guidance. Targeting accuracy of the system was evaluated with a real-time MRI-guided phantom study, demonstrating the mean absolute errors (MAE) of the tip position to be 1.50±0.68mm and of the needle angle to be 1.56±0.93°. An initial cadaver study was performed to validate the feasibility of the clinical workflow, indicating the maximum error of the position to be less than 1.90mm and of the angle to be less than 3.14°.

Image-guided Sports Medicine and Musculoskeletal Tumor Interventions: A Patient-Centered Model

The spectrum of effective musculoskeletal (MSK) interventions is broadening and rapidly evolving. Increasing demands incite a perpetual need to optimize services and interventions by maximizing the diagnostic and therapeutic yield, reducing exposure to ionizing radiation, increasing cost efficiency, as well as identifying and promoting effective procedures to excel in patient satisfaction ratings and outcomes. MSK interventions for the treatment of oncological conditions, and conditions related to sports injury can be performed with different imaging modalities; however, there is usually one optimal image guidance modality for each procedure and individual patient. We describe our patient-centered workflow as a model of care that incorporates state-of-the-art imaging techniques, up-to-date evidence, and value-based practices with the intent of optimizing procedural success and outcomes at a patient-specific level. This model contrasts interventionalist- and imaging modality-centered practices, where procedures are performed based on local preference and selective availability of imaging modality or interventionalists. We discuss rationales, benefits, and limitations of fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging procedure guidance for a broad range of image-guided MSK interventions to diagnose and treat sports and tumor-related conditions.

Ultrasound-Guided Lumbar Transforaminal Epidural Injection: A Narrative Review

Transforaminal epidural steroid injection is often administered to patients with radiculopathy under fluoroscopic guidance, although it has disadvantages of radiation hazards and requirement of a special area to perform the block. To avoid these disadvantages, ultrasound-guided transforaminal injection (USTFI) has recently been described and is continually developed. This review article describes the indexed articles published on USTFI and ultrasound-guided selective nerve block (SNRB) to evaluate current evidence on best approach to perform the block. Through literature search, eight articles and one case report on USTFI and five articles on ultrasound-guided SNRB were found. Most of the studies have utilized parasagittal orientation of curvilinear probe to perform the block. Nevertheless, with the present literature, it is difficult to come to any conclusion. Further studies with larger sample size and description of dye spread patterns are recommended to come to a more definite conclusion.

Measurement of spinal root angle at spinal canal and foraminal levels in cases of facet arthropathy: T2-weighted turbo spin echo magnetic resonance myelography with SPACE technique

BACKGROUND

Magnetic resonance myelography (MRM) with three-dimensional (3D) T2-weighted (T2W) turbo spin echo (TSE) sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) may be a guide to the etiology of low back pain.

PURPOSE

To research the efficiency of a 3D T2W TSE SPACE MRM sequence for visualization of anatomic details of spinal nerve root at the spinal canal and lateral recess levels in the patients with low back pain.

MATERIAL AND METHODS

Lumbar spinal MRM 3D T2W TSE SPACE was performed in a total of 70 patients (median age 46 years). Patients were imaged while lying in a supine position with straightened legs. According to the degree of facet arthropathy findings, patients were divided into four separate subgroups in our retrospective cross-sectional study. Spinal nerve root angle was measured within the spinal canal and at lateral recess level, and facet joint angle and lumbar lordosis measurements were measured by two radiologists, independently.

RESULTS

Lumbar level was strongly negatively correlated with facet joint angle (r = -0.95) as well as nerve root angle within the spinal canal (NRA_SC) (r = -0.857) and at the lateral recess level (NRA_LR) (r = -0.947). Intracanal decline of the spinal root angle caused by spinal stenosis findings was also observed (P < 0.05). For the measurements of NRA_SC and NRA_LR, inter-observer correlation was 0.85 and 0.82 for the spinal canal and at lateral recess level, respectively.

CONCLUSION

3D T2W SPACE in NRA_SC and NRA_LR provided high resolution images for evaluation. Therefore, this method may be a qualitative guide for the clinician and the surgeon in terms of root anatomy before any intervention.

Body-mounted robotic assistant for MRI-guided low back pain injection

PURPOSE

This paper presents the development of a body-mounted robotic assistant for magnetic resonance imaging (MRI)-guided low back pain injection. Our goal was to eliminate the radiation exposure of traditional X-ray guided procedures while enabling the exquisite image quality available under MRI. The robot is designed with a compact and lightweight profile that can be mounted directly on the patient's lower back via straps, thus minimizing the effect of patient motion by moving along with the patient. The robot was built with MR-conditional materials and actuated with piezoelectric motors so it can operate inside the MRI scanner bore during imaging and therefore streamline the clinical workflow by utilizing intraoperative MR images.

METHODS

The robot is designed with a four degrees of freedom parallel mechanism, stacking two identical Cartesian stages, to align the needle under intraoperative MRI-guidance. The system targeting accuracy was first evaluated in free space with an optical tracking system, and further assessed with a phantom study under live MRI-guidance. Qualitative imaging quality evaluation was performed on a human volunteer to assess the image quality degradation caused by the robotic assistant.

RESULTS

Free space positioning accuracy study demonstrated that the mean error of the tip position to be [Formula: see text] mm and needle angle to be [Formula: see text]. MRI-guided phantom study indicated the mean errors of the target to be [Formula: see text] mm, entry point to be [Formula: see text] mm, and needle angle to be [Formula: see text]. Qualitative imaging quality evaluation validated that the image degradation caused by the robotic assistant in the lumbar spine anatomy is negligible.

CONCLUSIONS

The study demonstrates that the proposed body-mounted robotic system is able to perform MRI-guided low back injection in a phantom study with sufficient accuracy and with minimal visible image degradation that should not affect the procedure.

Effect of Poly(Lactide-Co-Glycolide) Nanoparticles on Local Retention of Fluorescent Material: An Experimental Study in Mice

Objective

Poly(lactide-co-glycolide) (PLGA) nanoparticles are promising materials for the development of new drug-releasing systems. The purpose of this study was to evaluate the in vivo retention time of materials loaded in nanoparticles as compared with that of the material alone by in vivo imaging in nude mice.

Materials and Methods

Mice (n = 20) were injected with 0.1 mL fluorescent material 1,1'-dioctadecyl-3,3,3',3' tetramethylindotricarbocyanine iodide (DiR)-loaded PLGA nanoparticles (200 nm) into the right paraspinal muscle, and the same volume of pure DiR solution was injected into the left paraspinal muscle. Fluorescence images were obtained using an in vivo optical imaging system. Fluorescent images were taken 1 day after the injection, and seven more images were taken at 1-week intervals. Image analysis was done with ImageJ program, and one region of interest was chosen manually, which corresponded to the highest signal-intensity area of fluorescence signal intensity.

Results

After 7 weeks, 12 mice showed a right-sided dominant signal, representing the DiR loaded PLGA nanoparticles; 5 mice showed a left-side dominant signal, representing the free DiR solution; and 3 mice showed no signal at all beginning 1 day after the injection. During the 7-week period, the mean signal intensities of the free DiR solution and DiR-loaded PLGA nanoparticles diverged gradually. On day 1, the mean signal intensity of free DiR solution was significantly higher than that of DiR-loaded PLGA (p < 0.001). Finally, by week 7, DiR-loaded PLGA express significantly high signal intensity compared with free DiR solution (p = 0.031).

Conclusion

The results of the current study suggested that therapeutic agents bound to PLGA nanoparticles may exhibit prolonged retention times.

Lumbar Dorsal Root Ganglion Block as a Prognostic Tool Before Pulsed Radiofrequency: A Randomized, Prospective, and Comparative Study on Cost-Effectiveness

OBJECTIVES

In the study, we discuss the predictive value and cost-effectiveness of dorsal root ganglion (DRG) blocks before using dorsal root ganglion pulsed radiofrequency (DRG-PRF) in the treatment of low back pain.

METHODS

The study comprised 60 patients with low back pain who were randomly assigned into 2 groups. Patients in group 1 were screened using DRG block before DRG-PRF treatment for responders. Patients in group 2 underwent DRG-PRF treatment without DRG block. Successful outcome was defined as patient satisfaction, improvement in numerical rating scale, and medication use reduction.

RESULTS

In group 1 (n = 30), 24 patients demonstrated good response to DRG block, and 20 patients had successful outcome at 6 months after DRG-PRF therapy. In group 2 (n = 30), 25 of the patients had successful outcome at 6 months after DRG-PRF therapy. The mean medical costs were NT$ 19,245 and NT$ 16,375 for each successful case in groups 1 and 2, respectively.

CONCLUSIONS

In this comparative cost-effectiveness study, the application of diagnostic DRG blocks before DRG-PRF did not have a significant impact on patient satisfaction, pain index score, or pain medication reduction. Furthermore, the application of diagnostic DRG blocks resulted in overall greater medical costs. These findings suggest that DRG-PRF without screening by DRG block is more cost-effective and less invasive.

Learning curve of radiology residents during training in fluoroscopy-guided facet joint injections

OBJECTIVE

To develop a simulator for training in fluoroscopy-guided facet joint injections and to evaluate the learning curve for this procedure among radiology residents.

MATERIALS AND METHODS

Using a human lumbar spine as a model, we manufactured five lumbar vertebrae made of methacrylate and plaster. These vertebrae were assembled in order to create an anatomical model of the lumbar spine. We used a silicon casing to simulate the paravertebral muscles. The model was placed into the trunk of a plastic mannequin. From a group of radiology residents, we recruited 12 volunteers. During simulation-based training sessions, each student carried out 16 lumbar facet injections. We used three parameters to assess the learning curves: procedure time; fluoroscopy time; and quality of the procedure, as defined by the positioning of the needle.

RESULTS

During the training, the learning curves of all the students showed improvement in terms of the procedure and fluoroscopy times. The quality of the procedure parameter also showed improvement, as evidenced by a decrease in the number of inappropriate injections.

CONCLUSION

We present a simple, inexpensive simulation model for training in facet joint injections. The learning curves of our trainees using the simulator showed improvement in all of the parameters assessed.

Comparison of lumbosacral transforaminal epidural steroid injection techniques in terms of radiation safety

Aim: To investigate the difference in radiation exposure to the patients between oblique and posteroanterior view, initial approach techniques in fluoroscopy-guided lumbosacral transforaminal epidural steroid injections. Patients & methods: Total amount of Kerma area product, elapsed time of the procedure and fluoroscopy time were obtained from medical records retrospectively. Results: 28 patients were included in each group. Fluoroscopy time was significantly lower in group 1, but there was no statistically significant difference in terms of procedure time and Kerma area product. Conclusion: Radiation risk does not change between these approaches.

Ultrasound-guided Versus Fluoroscopy-controlled Lumbar Transforaminal Epidural Injections: A Prospective Randomized Clinical Trial

OBJECTIVES

Recently, most lumbar spine injections have been administered under ultrasound (US) guidance; however, there is no standard method for US-guided lumbar transforaminal epidural injection (TFEI). In this study, we evaluated the accuracy, effect on pain relief, and safety of US-guided lumbar TFEI.

METHODS

A total of 80 patients with low back pain and radicular pain were enrolled. The patients were randomly assigned to either the fluoroscopy (FL) group or the US group. The FL-guided approaches were performed under standardized procedures using the C-arm, whereas the US-guided injections were performed with an US device with a linear probe, and were verified by FL. The needle tip reached the lateral side of the lamina in the axis view and the middle of the adjacent facet joints in the parasagittal view. Afterward, the needle was advanced slightly deeper until the loss-of-resistance test was positive.

RESULTS

The success ratio of the US-guided interventions was 85%. The operation time in the US group (518±103 s) was shorter than the FL group (929±228 s) (P<0.05). In addition, the radiation dosage in the US group (2640±906 μGy m²) was lower than in the FL group (8992±2132 μGy m²). There was no significant difference in pain relief between the US and FL groups. No serious complication was observed in any of the patients in either group.

DISCUSSION

Lumbar TFEI under US guidance was feasible, safe, and required less radiation to achieve the same benefit as the FL-guided interventions.

Magnetic Resonance Imaging-Guided Spine Interventions

MR imaging-guided interventions for treatment of low back pain and for diagnosis and treatment of soft tissue and bony spinal lesions have been shown to be feasible, effective, and safe. Advantages of this technique include the absence of ionizing radiation, the high tissue contrast, and multiplanar imaging options. Recent advancements in MR imaging systems allow improved image qualities and real-time guidance. One exciting application is MR imaging-guided cryotherapy of spinal lesions, including treating such lesions as benign osteoid osteomas and malignant metastatic disease in patients who are not good surgical candidates. This particular technique shows promise for local tumor control and pain relief in appropriate patients.

Effect of facet joint injection versus systemic steroids in low back pain: a randomized controlled trial

STUDY DESIGN

Randomized clinical trial.

OBJECTIVE

To compare the effectiveness of facet joint injection versus systemic steroid in patients with a diagnosis of facet joint syndrome.

SUMMARY OF BACKGROUND DATA

The term facet joint syndrome has been used to define back pain originating from the facet joints. Treatment is mainly conservative, although interventions, including intra-articular injections and medial branch nerve blocks are used to manage facet-mediated pain. Several studies have evaluated the effectiveness of these interventions. Results of facet joint injection, however, are conflicting.

METHODS

Sixty subjects with a diagnosis of facet joint syndrome were enrolled in the study. They were randomized into experimental and control groups. The experimental group was administered with intra-articular injection of 6 lumbar facet joints with triamcinolone hexacetonide; the control group was administered with triamcinolone acetonide intramuscular injection of 6 lumbar paravertebral points. Visits were taken at baseline and at 1, 4, 12, and 24 weeks after interventions. Outcome measures were used: pain visual analogue scale, pain visual analogue scale during extension of the spine, Likert scale, improvement percentage scale, Roland-Morris, 36-Item Short Form Health Survey, and accountability of medications taken.Homogeneity was tested using the Student t, Pearson χ, and Mann-Whitney tests. Analysis of variance was used to analyze differences in the groups over time and the Student t test to analyze differences between groups at each time evaluation.

RESULTS

The groups were similar at baseline. Comparisons between the groups showed, in analysis of variance analysis, an improvement in the experimental group regarding diclofenac intake and quality of life, in the "role physical" profile, assessed by 36-Item Short Form Health Survey.In the analysis at each time point, an improvement in the experimental group was also found in the Roland-Morris questionnaire, in the improvement percentage scale and in the response to treatment, assessed by the Likert scale.

CONCLUSION

Both treatments were effective, with a slight superiority of the intra-articular injection of steroids over intramuscular injection.

Magnetic resonance neurography-guided nerve blocks for the diagnosis and treatment of chronic pelvic pain syndrome

Magnetic resonance (MR) neurography - guided nerve blocks and injections describe a techniques for selective percutaneous drug delivery, in which limited MR neurography and interventional MR imaging are used jointly to map and target specific pelvic nerves or muscles, navigate needles to the target, visualize the injected drug and detect spread to confounding structures. The procedures described, specifically include nerve blocks of the obturator nerve, lateral femoral cutaneous nerve, pudendal nerve, posterior femoral cutaneous nerve, sciatic nerve, ganglion impar, sacral spinal nerve, and injection into the piriformis muscle.

Efficacy of therapeutic fluoroscopy-guided lumbar spine interventional procedures

PURPOSE

To evaluate the benefit of fluoroscopy-guided lumbar spine interventional procedures in treatment of low back pain.

METHODS

This prospective descriptive study was performed on 60 patients with back/radicular pain after showing no improvement with conservative treatment.

RESULTS

One hundred and two injection sessions were done (average 1.7 injection per patient). Caudal and lumbar transforaminal injections were effective in 55.9% and 78.5%, respectively. Facet and sacroiliac interventions were effective in 28.3% and 10%, respectively. Complications occurred in 20% of the procedures.

CONCLUSION

Lumbar injections improved pain/disability related to discogenic lumbar spinal diseases. Efficacy of facet and sacroiliac injections is limited.

[Imaging-guided injection techniques of the lumbar spine]

Spinal injections are an important treatment option in the conservative management of many spinal disorders. A large number of imaging techniques are available to achieve a precise and safe needle placement in interventional procedures. Fluoroscopy-guided injections are safe, cost effective and available in most institutions. The following article presents an overview of common fluoroscopy-guided spinal injection therapy of the lumbar spine.

High-resolution magnetic resonance-guided posterior femoral cutaneous nerve blocks

OBJECTIVE

To assess the feasibility, technical success, and effectiveness of high-resolution magnetic resonance (MR)-guided posterior femoral cutaneous nerve (PFCN) blocks.

MATERIALS AND METHODS

A retrospective analysis of 12 posterior femoral cutaneous nerve blocks in 8 patients [6 (75%) female, 2 (25%) male; mean age, 47 years; range, 42-84 years] with chronic perineal pain suggesting PFCN neuropathy was performed. Procedures were performed with a clinical wide-bore 1.5-T MR imaging system. High-resolution MR imaging was utilized for visualization and targeting of the PFCN. Commercially available, MR-compatible 20-G needles were used for drug delivery. Variables assessed were technical success (defined as injectant surrounding the targeted PFCN on post-intervention MR images) effectiveness, (defined as post-interventional regional anesthesia of the target area innervation downstream from the posterior femoral cutaneous nerve block), rate of complications, and length of procedure time.

RESULTS

MR-guided PFCN injections were technically successful in 12/12 cases (100%) with uniform perineural distribution of the injectant. All blocks were effective and resulted in post-interventional regional anesthesia of the expected areas (12/12, 100%). No complications occurred during the procedure or during follow-up. The average total procedure time was 45 min (30-70) min.

CONCLUSIONS

Our initial results demonstrate that this technique of selective MR-guided PFCN blocks is feasible and suggest high technical success and effectiveness. Larger studies are needed to confirm our initial results.

[Injection techniques in the cervical spine]

Spinal injections are a treatment option in the conservative management of degenerative spinal disorders. The indications must be critically reviewed for every patient. Treatment with injections for painful spinal disorders should be a part of interdisciplinary treatment regimes. The diagnostic value varies between injection procedures. A large number of imaging techniques are used to achieve a precise and safe needle placement in interventional procedures. The following article presents an overview of common fluoroscopy-guided spinal injection techniques for the cervical spine.

Magnetic resonance imaging-guided spine injections

Magnetic resonance (MR)-guided spine injections describe techniques for selective spine injection procedures, in which MR imaging is used to visualize spinal targets and needle placement, monitor the injected drugs, and detect spread to potentially confounding nearby structures. The introduction of clinical high-field wide-bore MR imaging systems has increased the practicability and availability of MR-guided spine injections. The use of 1.5-T field strength, modern coils, and parallel imaging technology increases the MR signal, which can be utilized for faster temporal image acquisition, higher image resolution, better image contrast, or combinations thereof. Magnetic resonance imaging guidance provides excellent osseous and soft-tissue detail of spinal structures and is well suited to avoid radiation exposure. In this article, we discuss the technical background of interventional MR imaging, review the literature, and illustrate interventional MR imaging techniques of commonly performed spinal injection procedures, including sacroiliac joint injections, lumbar facet joint injections, selective spinal nerve root infiltration, and percutaneous drug delivery to the lumbar sympathetic nerves.

A new simplified sonographic approach for pararadicular injections in the lumbar spine: a CT-controlled cadaver study

BACKGROUND AND PURPOSE

Injection therapies play a major role in the treatment of lower back pain and are to date performed mainly under CT or fluoroscopic guidance. The benefits of US-guided instillation procedures have been shown in many studies. We conducted this study to simplify an US-guided approach to the lumbar spinal nerves and to assess the feasibility and preliminary accuracy by means of CT and anatomic dissection.

MATERIALS AND METHODS

Ten US-guided injections at 5 different levels (L1-L5) were performed on 1 embalmed cadaver. Images in 3 sagittal/parasagittal scanning planes were obtained at each lumbar level: 1) the plane of the spinous processes, 2) the plane of the lumbar arches/zygapophyseal-joints, and 3) the plane of the transverse processes. The PAP was then defined by positioning the transducer perpendicularly over the medial part of the respective transverse processes, depicting the hyperechoic intertransverse ligament. In the "in-plane technique," spinal needles were advanced through the respective segmental intertransverse ligament. A solution consisting of a contrast agent and a pigmented dispersion was subsequently injected into the pararadicular compartment. An anatomic dissection of the specimen and CT scans were performed to verify the exact placement of the needle tips and to evaluate fluid dispersion in the punctured compartment.

RESULTS

CT examination confirmed that each needle tip was correctly placed within the intended compartment with sufficient contrast accumulation around the respective proximal segment of the spinal nerve. On each anatomic section, dye was identified in the correct compartment and directly around each targeted spinal nerve with needles shown in the correct position.

CONCLUSIONS

This modified US approach for therapeutic root injections in the lumbar spine by using the intertransverse ligament as a new anatomic landmark allows an easy and correct needle placement within the pararadicular compartment.

Image-guided facet joint injection

Chronic spine pain poses a peculiar diagnostic and therapeutic challenge due to multiple pain sources, overlapping clinical features and nonspecific radiological findings. Facet joint injection is an interventional pain management tool for facet-related spinal pain that can be effectively administered by a radiologist. This technique is the gold standard for identifying facet joints as the source of spinal pain. The major indications for facet injections include strong clinical suspicion of the facet syndrome, focal tenderness over the facet joints, low back pain with normal radiological findings, post-laminectomy syndrome with no evidence of arachnoiditis or recurrent disc disease, and persistent low back pain after spinal fusion. The contraindications are more ancillary, with none being absolute. Like any synovial joint degeneration, inflammation and injury can lead to pain on motion, initiating a vicious cycle of physical deconditioning, irritation of facet innervations and muscle spasm. Image-guided injection of local anesthetic and steroid into or around the facet joint aims to break this vicious cycle and thereby provide pain relief. This outpatient procedure has high diagnostic accuracy, safety and reproducibility but the therapeutic outcome is variable.

Acute back pain: benefits and risks of current treatments

OBJECTIVE

To review the efficacy and safety of current treatments for acute low back pain.

RESEARCH DESIGN AND METHODS

PubMed was searched for clinical trials in which the words, acute, back, and pain all appeared in the study summary. The search was from the earliest references included in this database (1949) until 1 May 2009. This resulted in retrieval of 129 papers. Review of study summaries indicated that 36 provided information about either a topical treatment or oral therapy for acute low back pain. In addition, studies included as part of the evidence base for the Evidence Review of American Pain Society/American Academy of Pain Medicine Evidence Review for Evaluation and Management of Low Back Pain were reviewed.

RESULTS

Recommended topical and systemic pharmacologic treatments for acute low back pain include application of superficial heat, acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), skeletal muscle relaxants/benzodiazepines, and opioids including tramadol. Only a small number of studies compared different approaches to treatment of acute back pain and most failed to demonstrate significant differences among treatments. Available results support the view that both NSAIDs and low-level continuous heat treatment are more effective than acetaminophen and that heat treatment is also significantly more effective than ibuprofen. A potential limitation of this study is that information from trials published in journals not included in PubMed or reported only at meetings and not yet published was not included.

CONCLUSIONS

A wide range of treatments is currently recommended for the management of patients with acute back pain and all are supported by results from controlled clinical trials.

Clinical study of low back pain and radicular pain pathways by using l2 spinal nerve root infiltration: a randomized, controlled, clinical trial

STUDY DESIGN

Randomized control trial (RCT) for L2 spinal nerve infiltration (L2 block) in clinical cases.

OBJECTIVES

To confirm or refute the effect of L2 block using RCT, and to study the pathway of low back pain (LBP) and radicular pain in clinical cases.

SUMMARY OF BACKGROUND DATA

It has been reported in animal experiments that one of the main pathways of pain originating from the lumbar spine is the sympathetic trunk through the L2 spinal nerve rootvia sympathetic afferents.

METHODS

To evaluate the effectiveness of L2 block, patients who had LBP and were treated with nonsteroidal anti-inflammatory drugs for at least 2 weeks were then randomized to the L2 block or control block groups. The intensities of LBP and radicular pain were measured using visual analog scale and face scale before and at 5 minutes and 7 days after the injection. These values were compared, and the effects of the injections on the pain pathway were studied.

RESULTS

The average visual analog scale scores for LBP before and at 5 minutes and 7 days after the injection were 69, 14, and 44 mm in the L2 block group and 68, 62, and 59 mm in the control block group, respectively. After L2 block, 28 patients reported adequate therapeutic effect at 10 weeks, and the effect lasted for more than 24 weeks in 10 of these patients. After control block, 9 patients reported adequate therapeutic effect at 10 and 24 weeks.

CONCLUSION

The LBP and radicular pain pathways were likely interrupted by L2 block. An L2 block is useful in reducing LBP due to the disorders of L2 spinal nerve-innervated structures, such as the disc, facet joint, and sacroiliac joint. However, the therapeutic value of an L2 block may be occasionally insufficient to alleviate pain completely because of the short duration of its' effect.