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1.  Transverse Process and Needles of Medial Branch Block to Facet Joint as Landmarks for Ultrasound-Guided Selective Nerve Root Block 
Clinics in Orthopedic Surgery  2013;5(1):44-48.
Selective lumbar nerve root block (SNRB) is generally accepted as an effective treatment method for back pain with sciatica. However, it requires devices producing radioactive materials such as C-arm fluoroscopy. This study evaluated the usefulness of the longitudinal view of transverse process and needles for medial branch block as landmarks under ultrasonography.
We performed selective nerve root block for 96 nerve roots in 61 patients under the guidance of ultrasound. A curved probe was used to identify the facet joints and transverse processes. Identifying the lumbar nerve roots under the skin surface and ultrasound landmarks, the cephalad and caudal medial branch blocks were undertaken under the transverse view of sonogram first. A needle for nerve root block was inserted between the two transverse processes under longitudinal view, while estimating the depth with the needle for medial branch block. We then injected 1.0 mL of contrast medium and checked the distribution of the nerve root with C-arm fluoroscopy to evaluate the accuracy. The visual analog scale (VAS) was used to access the clinical results.
Seven SNRBs were performed for the L2 nerve root, 15 for L3, 49 for L4, and 25 for L5, respectively. Eighty-six SNRBs (89.5%) showed successful positioning of the needles. We failed in the following cases: 1 case for the L2 nerve root; 2 for L3; 3 for L4; and 4 for L5. The failed needles were positioned at wrong leveled segments in 4 cases and inappropriate place in 6 cases. VAS was improved from 7.6 ± 0.6 to 3.5 ± 1.3 after the procedure.
For SNRB in lumbar spine, the transverse processes under longitudinal view as the ultrasound landmark and the needles of medial branch block to the facet joint can be a promising guidance.
PMCID: PMC3582870  PMID: 23467334
Lumbar spine; Spinal injections; Ultrasound
2.  Comparison of Ultrasonography- and Fluoroscopy-Guided Facet Joint Block in the Lumbar Spine 
Asian Spine Journal  2010;4(1):15-22.
Study Design
Retrospective study.
Facet joint block is performed for diagnostic or therapeutic purposes and generally carried out under computerd tomography (CT) or radiologic fluoroscopy guidance. Ultrasonography-guided facet block has recently been attempted. So, we compared the results of ultrasonography-guided facet joint block with the results of fluoroscopy-guided facet joint block.
Overview of Literature
Because fluoroscopic or CT guided facet joint block has been reported side effects, we performed spinal facet block using a fluoroscopy-guided method.
We selected 133 patients who had lumbar pain or referred pain. They were diagnosed as having spinal stenosis and hospitalized from January 2008 to June 2008. As the subjects, we selected 105 patients who had been follow-up for more than 6 months and carried out a prospective study.
Twenty six subjects were male and 25 were female in the fluoroscopy group (group 1) and their mean age was 56.1 years (range, 45 to 79 years). Twenty one were male and 33 were female in the ultrasonography-guided group (group 2). Their mean age was 58.3 years (range, 47 to 83 years). We studied the average time of the procedures, complications, the difference of the therapeutic cost between the two groups. We also evaluated the visual analogue scale (VAS) score and the Oswestry disability index.
The procedure in group 2 averaged 4 minutes and 25 seconds, and in group 1, 4 minutes and 7 seconds. The coast was an average of 38,000 won in group 2 and 25,000 won in group 1. The VAS score was improved from an average of 7.5 (range, 5 to 9) to 2.8 (range, 2 to 6) in group 2 and from 7.8 (range, 4 to 10) to 2.7 (range, 2 to 5) in group 1. The Oswestry disability index was improved from an average of 32.3 (range, 28 to 41) to 23.5 (range, 17 to 26) in group 2 and from 34.2 (range, 29 to 43) to 24.8 (range, 18 to 28) in group 1. As for complications, worsening of lumbar pain, paresthesia, headache and allergic reaction were detected in 5 cases of group 2 and in 3 of group 1. Those symptoms were improved within several hours. One case of superficial infection that developed in group 2 was improved within several days.
We should consider that ultrasonography-guided facet joint block is a minimal invasive procedure that is easily carried out without radiation exposure.
PMCID: PMC2900164  PMID: 20622950
Lumbar pain; Ultrasonography; Facet joint block
3.  Ultrasound-guided combined intermediate and deep cervical plexus nerve block for regional anaesthesia in oral and maxillofacial surgery 
Dentomaxillofacial Radiology  2013;42(2):29945724.
We examined the application of an ultrasound-guided combined intermediate and deep cervical plexus nerve block for regional anaesthesia in patients undergoing oral and maxillofacial surgery.
A total of 19 patients receiving ultrasound-guided combined intermediate and deep cervical plexus anaesthesia followed by neck surgery were examined prospectively. The sternocleidomastoid and the levator of the scapula muscles as well as the cervical transverse processes were used as easily depicted ultrasound landmarks for the injection of local anaesthetics. Under ultrasound guidance, a needle was advanced in the fascial band between the sternocleidomastoid and the levator of the scapula muscles and 15 ml of ropivacaine 0.75% was injected. Afterwards, the needle was advanced between the levator of the scapula and the hyperechoic contour of the cervical transverse processes and a further 15 ml of ropivacaine 0.75% was injected. The sensory block of the cervical nerve plexus, the analgesic efficacy of the block within 24 h after injection and potential block-related complications were assessed.
All patients showed a complete cervical plexus nerve block. No patient required analgesics within the first 24 h after anaesthesia. Two cases of blood aspiration were recorded. No further cervical plexus block-related complications were observed.
Ultrasound-guided combined intermediate and deep cervical plexus block is a feasible, effective and safe method for oral and maxillofacial surgical procedures.
PMCID: PMC3699012  PMID: 22933534
cervical plexus; interventional ultrasonography; nerve block
4.  Thoracolumbar Junction Syndrome Causing Pain around Posterior Iliac Crest: A Case Report 
Korean Journal of Family Medicine  2013;34(2):152-155.
Thoracolumbar junction syndrome is characterized by referred pain which may originate at the thoracolumbar junction, which extends from 12th thoracic vertebra to 2nd lumbar vertebra, due to functional abnormalities. Clinical manifestations include back pain, pseudo-visceral pain and pseudo-pain on the posterior iliac crest, as well as irritable bowel symptoms. During clinical examination, pain can be demonstrated by applying pressure on the facet joints or to the sides of the spinous processes. Radiological studies show only mild and insignificant degenerative changes in most cases. We report a 42-year-old female patient with osteogenesis imperfecta who suffered from chronic low back pain. Under the diagnosis of thoracolumbar junction syndrome, she was treated with an epidural block and a sympathetic nerve block, which improved her symptoms.
PMCID: PMC3611104  PMID: 23560215
Vertebrae; Thoracic; Lumbar; Back Pain; Iliac
5.  Ultrasound and electrical nerve stimulation-guided S1 nerve root block 
Journal of Anesthesia  2013;27:775-777.
A selective lumbosacral nerve root block is generally is performed under X-ray fluoroscopy, which has the disadvantage of radiation exposure and the need for fluoroscopy equipment. In this study, we assessed the effectiveness of ultrasound and nerve stimulation-guided S1 nerve root block on 37 patients with S1 radicular syndrome. With the patient in a prone position, an ultrasound scan was performed by placing the probe parallel to the body axis. The needle was pointed slightly medial from the lateral side of the probe and advanced toward a hyperechoic area in the sacral foramina with ultrasound guidance. Contrast medium was then injected and its dispersion confirmed by fluoroscopy. The acquired contrast images were classified into intraneural, perineural, and paraneural patterns. The significance of differences in the effect of the block among the contrast image patterns was analyzed. After nerve block, decreased sensation at the S1 innervated region and pain relief was achieved in all patients. No significant difference was noted in the effect of the block between perineural and paraneural patterns. In conclusion, this technique provided reliable S1 nerve root block in patients with S1 radicular syndrome and minimized radiation exposure.
PMCID: PMC3825138  PMID: 23494676
Ultrasound; Nerve stimulation; Nerve root block
6.  Survey of Sonoanatomic Distances For Lumbar Medial Branch Nerve Blocks in Healthy Volunteers 
The Korean Journal of Pain  2014;27(2):133-138.
The precise knowledge of anatomy and the region of transverse process (TP) and superior articular processes (AP) and their distance from the skin are important in blocking and treating lumbar facet syndrome. Evaluation of these anatomic distances from 3rd and 5th lumbar vertebrae in both sides and in different body mass index (BMI) in healthy volunteers might improve knowledge of ultrasound (US) lumbar medial branch nerve blocks (LMBB).
Bilateral US in the 3rd and 5th lumbar vertebrae of 64 volunteers carried out and the distance between skin to TP and skin to AP was measured. These distances were compared on both sides and in different BMI groups. The analysis was done using SPSS 11. Analysis of variance was used to compare the means at three vertebral levels (L3-L5) and different BMI groups. P values less than 0.05 were considered statistically significant. The paired t-test was used to compare the mean distance between skin to TP and skin to AP on both sides.
The distance between skin to TP and skin to AP of 3rd vertebrae to 5th vertebrae was increased in both right and left sides (P < 0.001) from up to down. The mean distance from skin to TP were greater on the left side compared to the right in all three vertebral levels from L3 to L5 (P values 0.014, 0.024, and 0.006 respectively). The mean distance from skin to TP and the skin to AP was statistically significant in different BMI groups (P < 0.001).
We found many anatomic distances which may increase awareness of US guided LMBB.
PMCID: PMC3990821  PMID: 24748941
medial branch nerve blocks; sonography; zygapophysial joint
7.  Echo-guided estimation of formula for paravertebral block in neonates, infants and children till 5 years 
Indian Journal of Anaesthesia  2012;56(4):382-386.
The aim of the study was to derive a clinically useful formula for paravertebral block for thoracic, lumbar (L1) and cervical level (C6) as per the ultrasound-guided measurements in neonates, infants and children up to 5 years of age.
Settings and Design:
Observational study.
Seventy-five patients from 2 days to 60 months were included. Paravertebral transverse ultrasound scans at cervical (C6), thoracic (T1-12) and lumbar (L1) regions were viewed to determine the optimal insertion point and depth for performing paravertebral blocks. The lateral distance from the spinous process to the insertion point and the depth from the insertion point to the paravertebral space or reference point (point just anterior to the transverse process) were measured.
Statistical Analysis:
Data was analyzed using the SPSS (V 10.0) package. Preliminary data was collected with the actual values of paravertebral parameters and weight and age. Initially, Pearson Bivariate Correlation Coefficients were calculated between parameters and age and weight so as to predict paravertebral parameters with the help of weight and age. As there were statistically significant associations between parameters and age and weight, an attempt was made to predict parameters with the help of age and weight. Multiple regression method (forward) was applied by taking parameters as dependent variables and age and weight as independent variables.
Age and weight correlated very well (statistically significant) with paravertebral parameters; hence, prediction (regression) equations were calculated as:
Prediction (regression) equation:
C6A=0.005 × wt + 0.005 × age + 1.31
C6B=0.009 × wt + 0.002 × age + 1.78
T1-12 A=0.02 × wt + 0.003 × age + 0.93
T1 to 12 B=0.03 × wt + 0.03 × age + 1.02
L1A=0.03 × wt + 0.02 × age + 0.91
L1B=0.05 × wt + 0.02 × age + 0.94
We could derive equations to predict the values for paravertebral blocks in centimetres at different levels in the study population.
PMCID: PMC3469918  PMID: 23087462
Formula; paravertebral block; patients; paediatric; ultrasound guidance
8.  Percutaneous CT-Guided Treatment of Lumbar Facet Joint Synovial Cysts 
HSS Journal  2009;5(2):165-168.
Symptomatic intraspinal lumbar facet joint synovial cysts can be managed both conservatively and surgically. Diagnosis of the lumbar facet joint cyst is made through cross-sectional imaging of the spine, either by computerized tomography (CT) scan, myelography, or most commonly magnetic resonance imaging. Conservative treatment by facet joint injection can be performed under fluoroscopic or CT guidance, although only CT guidance provides direct visualization of the cyst confirming accurate needle placement. This case report illustrates the use of percutaneous CT-guided facet joint cyst treatment as a temporizing measure or alternative to surgical treatment in the proper clinical scenario.
PMCID: PMC2744762  PMID: 19597890
CT-guided injections; lumbar facet joint cysts
9.  Ultrasound-Guided Greater Occipital Nerve Blocks and Pulsed Radiofrequency Ablation for Diagnosis and Treatment of Occipital Neuralgia 
Anesthesiology and Pain Medicine  2013;3(2):256-259.
Occipital neuralgia is a condition manifested by chronic occipital headaches and is thought to be caused by irritation or trauma to the greater occipital nerve (GON). Treatment for occipital neuralgia includes medications, nerve blocks, and pulsed radiofrequency ablation (PRFA). Landmark-guided GON blocks are the mainstay in both the diagnosis and treatment of occipital neuralgia. Ultrasound is being utilized more and more in the chronic pain clinic to guide needle advancement when performing procedures; however, there are no reports of ultrasound used to guide a diagnostic block or PRFA of the GON. We report two cases in which ultrasound was used to guide diagnostic greater occipital nerve blocks and greater occipital nerve pulsed radiofrequency ablation for treatment of occipital neuralgia. Two patients with occipital headaches are presented. In Case 1, ultrasound was used to guide diagnostic blocks of the greater occipital nerves. In Case 2, ultrasound was utilized to guide placement of radiofrequency probes for pulsed radiofrequency ablation of the greater occipital nerves. Both patients reported immediate, significant pain relief, with continued pain relief for several months. Further study is needed to examine any difference in outcomes or morbidity between the traditional landmark method versus ultrasound-guided blocks and pulsed radiofrequency ablation of the greater occipital nerves.
PMCID: PMC3833045  PMID: 24282778
Pulsed Radiofrequency Treatment; Headache Disorders; Pain; Ultrasonography; Nerve Block
10.  Ultrasonographic Measurement of the Ligamentum Flavum Depth; Is It a Reliable Method to Distinguish True and False Loss of Resistance? 
The Korean Journal of Pain  2012;25(2):99-104.
Previous studies have shown that if performed without radiographic guidance, the loss of resistance (LOR) technique can result in inaccurate needle placement in up to 30% of lumbar epidural blocks. To date, no study has shown the efficacy of measuring the depth of the posterior complex (ligamentum flavum, epidural space, and posterior dura) ultrasonographically to distinguish true and false LOR.
40 cervical epidural blocks were performed using the LOR technique and confirmed by epidurograms. Transverse ultrasound images of the C6/7 area were taken before each cervical epidural block, and the distances from the skin to the posterior complex, transverse process, and supraspinous ligament were measured on each ultrasound view. The number of LOR attempts was counted, and the depth of each LOR was measured with a standard ruler. Correlation of false and true positive LOR depth with ultrasonographically measured depth was also statistically analyzed.
76.5% of all cases (26 out of 34) showed false positive LOR. Concordance correlation coefficients between the measured distances on ultrasound (skin to ligamentum flavum) and actual needle depth were 0.8285 on true LOR. Depth of the true positive LOR correlated with height and weight, with a mean of 5.64 ± 1.06 cm, while the mean depth of the false positive LOR was 4.08 ± 1.00 cm.
Ultrasonographic measurement of the ligamentum flavum depth (or posterior complex) preceding cervical epidural block is beneficial in excluding false LOR and increasing success rates of cervical epidural blocks.
PMCID: PMC3324748  PMID: 22514777
cervical; epidural; ultrasonography
11.  Ultrasound guided lumbar puncture in emergency department: Time saving and less complications 
Lumbar puncture (LP) is an essential procedure in the diagnosis and treatment of several critical situations. This procedure is routinely performed by palpating external landmarks to find the most appropriate inter-spinous space. In the current study, we compared surface landmark and ultrasound (US) guided LP in different aspects.
Materials and Methods:
This clinical trial study was conducted at the emergency department (ED) of a teaching hospital from March 2009 to March 2010. Eighty patients were allocated randomly in two equal groups. In first group, LP was performed by US-guided method and in the control group by palpation of external landmarks of spinal column. Pain score, number of attempts for successful dural penetration, numbers of traumatic LP, and procedure time were compared between two groups. The performance of US-guided LP was assessed with regard to body mass index (BMI) of patients too.
The mean of procedure time and pain scores were markedly higher in land mark group in comparison to US group (6.4 ± 1.2 and 7.4 ± 1.1 vs. 3.3 ± 1.2 and 4.4 ± 1.4 respectively). Number of attempts and number of traumatic LPs were significantly lower in US group too. In patients with different subgroups of BMI, US-guided LP showed better results and less complication when compared with surface landmark guided technique. All of these results were statistically significant.
This study showed that US was able to find pertinent landmarks to facilitate the LP in patients admitted to ED and resulted in less pain and less time wasting. Moreover, patients who have high BMI may benefit more than others.
PMCID: PMC3793375  PMID: 24124427
Complication; emergency department; lumbar puncture; ultrasound
12.  Image-guided lumbar facet joint infiltration in nonradicular low back pain 
To assess the efficacy of facet joint infiltrations for pain relief in 44 selected patients with chronic nonradicular low back pain (LBP).
Materials and Methods:
Forty-four patients with chronic LBP of more than 3 months' duration were selected for facet joint infiltration. The majority (n = 24) had facetal pain with no evidence of significant facetal arthropathy on imaging. Fifteen patients had radiological evidence of facetal arthropathy, one had a facet joint synovial cyst, three were post–lumbar surgery patients, and two patients had spondylolysis. Facet joint injections were carried out under fluoroscopic guidance in 39 patients and under CT guidance in 5 cases. Pain relief was assessed using the visual analog scale at 1 h post-procedure and, thereafter, at 1, 4, 12, and 24 weeks.
A total of 141 facet joints were infiltrated in 44 patients over a 2-year period. There was significant pain relief in 81.8% patients 1 h after the procedure, in 86.3% after 1 week, in 93.3% after 4 weeks, in 85.7% after 12 weeks, and in 62.5% after 24 weeks. No major complications were encountered.
Facet nerve block was found to be a simple, minimally invasive, and safe procedure. With meticulous patient selection, we achieved long-term success rates of over 60%. We conclude that this method represents an important alternative treatment for nonradicular back pain.
PMCID: PMC2747413  PMID: 19774136
Facetal arthropathy; facetal infiltrations; low back pain
13.  Sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region 
The British Journal of Radiology  2012;85(1015):e262-e269.
The use of ultrasound to guide peripheral nerve blocks is now a well-established technique in regional anaesthesia. However, despite reports of ultrasound guided epidural access via the paramedian approach, there are limited data on the use of ultrasound for central neuraxial blocks, which may be due to a poor understanding of spinal sonoanatomy. The aim of this study was to define the sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach.
The sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach was defined using a “water-based spine phantom”, young volunteers and anatomical slices rendered from the Visible Human Project data set.
The water-based spine phantom was a simple model to study the sonoanatomy of the osseous elements of the lumbar spine. Each osseous element of the lumbar spine, in the spine phantom, produced a “signature pattern” on the paramedian sagittal scans, which was comparable to its sonographic appearance in vivo. In the volunteers, despite the narrow acoustic window, the ultrasound visibility of the neuraxial structures at the L3/L4 and L4/L5 lumbar intervertebral spaces was good, and we were able to delineate the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach.
Using a simple water-based spine phantom, volunteer scans and anatomical slices from the Visible Human Project (cadaver) we have described the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region.
PMCID: PMC3474051  PMID: 22010025
14.  Efficacy of Ultrasonography-Guided Injections in Patients with Facet Syndrome of the Low Lumbar Spine 
To investigate the efficacy of ultrasonography (US)-guided injections in patients with low lumbar facet syndrome, compared with that in patients who received fluoroscopy (FS)-guided injections.
Fifty-seven subjects with facet syndrome of the lumbar spine of the L4-5 and L5-S1 levels were randomly divided into two groups to receive intraarticular injections into the facet joint. One group received FS-guided facet joint injections and the other group received US-guided facet joint injections. Treatment effectiveness was assessed using a visual analogue scale (VAS), physician's and patient's global assessment (PhyGA, PaGA), and the modified Oswestry Disability Index (MODI). All parameters were evaluated four times: before injections, and at a week, a month, and three months after injections. We also measured, in both groups, how long it took to complete the whole procedure.
Each group showed significant improvement from the facet joint injections on the VAS, PhyGA, PaGA, and MODI (p<0.05). However at a week, a month, and three months after injections, no significant differences were observed between the groups with regard to VAS, PhyGA, PaGA, and MODI (p>0.05). Statistically significant differences in procedure time were observed between groups (FS: 248.7±6.5 sec; US: 263.4±5.9 sec; p=0.023).
US-guided injections in patients with lumbar facet syndrome are as effective as FS-guided injections for pain relief and improving activities of daily living.
PMCID: PMC3309334  PMID: 22506237
Intraarticular injections; Zygapophysial joint; Low-back pain; Ultrasonography
15.  Evaluation of Lumbar Facet Joint Nerve Blocks in Managing Chronic Low Back Pain: A Randomized, Double-Blind, Controlled Trial with a 2-Year Follow-Up 
Study Design: A randomized, double-blind, controlled trial.
Objective: To determine the clinical effectiveness of therapeutic lumbar facet joint nerve blocks with or without steroids in managing chronic low back pain of facet joint origin.
Summary of Background Data: Lumbar facet joints have been shown as the source of chronic pain in 21% to 41% of low back patients with an average prevalence of 31% utilizing controlled comparative local anesthetic blocks. Intraarticular injections, medial branch blocks, and radiofrequency neurotomy of lumbar facet joint nerves have been described in the alleviation of chronic low back pain of facet joint origin.
Methods: The study included 120 patients with 60 patients in each group with local anesthetic alone or local anesthetic and steroids. The inclusion criteria was based upon a positive response to diagnostic controlled, comparative local anesthetic lumbar facet joint blocks.
Outcome measures included the numeric rating scale (NRS), Oswestry Disability Index (ODI), opioid intake, and work status, at baseline, 3, 6, 12, 18, and 24 months.
Results: Significant improvement with significant pain relief of ≥ 50% and functional improvement of ≥ 40% were observed in 85% in Group 1, and 90% in Group II, at 2-year follow-up.
The patients in the study experienced significant pain relief for 82 to 84 weeks of 104 weeks, requiring approximately 5 to 6 treatments with an average relief of 19 weeks per episode of treatment.
Conclusions: Therapeutic lumbar facet joint nerve blocks, with or without steroids, may provide a management option for chronic function-limiting low back pain of facet joint origin.
PMCID: PMC2880841  PMID: 20567613
Chronic low back pain; lumbar facet or zygapophysial joint pain; facet joint nerve or medial branch blocks; comparative controlled local anesthetic blocks; therapeutic lumbar facet joint nerve blocks
16.  Lumbar pedicle: surgical anatomic evaluation and relationships 
European Spine Journal  2000;10(1):10-15.
Although several clinical applications of transpedicular screw fixation in the lumbar spine have been documented for many years, few anatomic studies concerning the lumbar pedicle and adjacent neural structures have been published. The lumbar pedicle and its relationships to adjacent neural structures were investigated through an anatomic study. Our objective is to highlight important considerations in performing transpedicular screw fixation in the lumbar spine. Twenty cadavers were used for observation of the lumbar pedicle and its relations. After removal of whole posterior bony elements including spinous processes, laminae, lateral masses, and inferior and superior facets, the isthmus of the pedicle was exposed. Pedicle width and height (PW and PH), interpedicular distance (IPD), pedicle-inferior nerve root distance (PIRD), pedicle-superior nerve root distance (PSRD), pedicle-dural sac distance (PDSD), root exit angle (REA), and nerve root diameter (NRD) were measured. The results indicated that the average distance from the lumbar pedicle to the adjacent nerve roots superiorly, inferiorly and to the dural sac medially at all levels ranged from 2.9 to 6.2 mm, 0.8 to 2.8 mm, and 0.9  to 2.1 mm, respectively. The mean PH and PW at L1–L5 ranged from 10.4 to 18.2 mm and 5.9 to 23.8 mm, respectively. The IPD gradually increased from L1 to L5. The mean REA increased consistently from 35° to 39°. The NRD was between 3.3 and 3.9 mm. Levels of significance were shown for the P<0.05 and P<0.01 levels. On the basis of this study, we can say that improper placement of the pedicle screw medially and inferiorly should be avoided.
PMCID: PMC3611478  PMID: 11276829
Anatomy Cadaver Lumbar pedicle Transpedicular fixation
17.  Magnetic resonance-guided focused ultrasound treatment of facet joint pain: summary of preclinical phase 
Study design
A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted to test the feasibility, safety, and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) for treating facet joint pain.
The goal of the current study was to develop a novel method for accurate and safe noninvasive facet joint ablation using MRgFUS.
Summary of background data
Facet joints are a common source of chronic back pain. Direct facet joint interventions include medial branch nerve ablation and intra-articular injections, which are widely used, but limited in the short and long term. MRgFUS is a breakthrough technology that enables accurate delivery of high-intensity focused ultrasound energy to create a localized temperature rise for tissue ablation, using MR guidance for treatment planning and real-time feedback.
We validated the feasibility, safety, and efficacy of MRgFUS for facet joint ablation using the ExAblate 2000® System (InSightec Ltd., Tirat Carmel, Israel) and confirmed the system's ability to ablate the edge of the facet joint and all terminal nerves innervating the joint. A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted.
The experiments showed that targeting the facet joint with energies of 150–450 J provides controlled and accurate heating at the facet joint edge without penetration to the vertebral body, spinal canal, or root foramina. Treating with reduced diameter of the acoustic beam is recommended since a narrower beam improves access to the targeted areas.
MRgFUS can safely and effectively target and ablate the facet joint. These results are highly significant, given that this is the first study to demonstrate the potential of MRgFUS to treat facet joint pain.
PMCID: PMC4036610  PMID: 24921048
Chronic back pain; Facet joints; MRgFUS; Pain palliation
18.  Upper extremity surgery in younger children under ultrasound-guided supraclavicular brachial plexus block: a case series 
Supraclavicular brachial plexus block is considered as one of the most effective anesthetic methods for upper extremity surgeries. Its major drawback, especially in children, is the risk of pneumothorax, vascular puncture, and failure of the procedure due to inaccurate placement of the needle. Ultrasound-guided needle placement may reduce the risk of complications and increase the accuracy of block, particularly in pediatric patients. There are few published experiences about the efficacy and safety of ultrasound-guided supraclavicular block in children and to our knowledge, it seems that there is no published report about its usage in younger children (less than 6 years of age).
In order to consider the efficacy of ultrasound in younger children, 17 patients aged between 6 months and 6 years were randomly selected. The ultrasound probe was used for proper placement of the needle. After confirmation of the needle location using a nerve locator, the anesthetic agent was injected. The procedure time, establishment time, duration of analgesia, any complications related to the procedure, and the surgeon’s satisfaction were recorded and analyzed.
The procedure time was 10.35 ± 1.22 min, the establishment time was 89.59 ± 18 s, and the duration of analgesia was between 6 and 16 h (mean 9.76 ± 2.57 h). The recovery time was 24.4 ± 6.5 min (range 15–37 min) and the duration of surgeries was 61.3 ± 25.9 min (range 15–110 min). There was no failure of the procedure. Also, there were no complications related to the procedure and the surgeon’s satisfaction during surgery was good or excellent.
This study demonstrates the efficacy and safety of the ultrasound-guided supraclavicular brachial plexus block for orthopedic upper extremity surgeries in patients younger than 6 years of age.
PMCID: PMC2908336  PMID: 21804893
Pediatric upper extremity surgery; Ultrasound; Supraclavicular; Brachial plexus block; Pediatric anesthesia; Regional anesthesia
19.  Ultrasound Guidance for Deep Peripheral Nerve Blocks: A Brief Review 
Nerve stimulation and ultrasound have been introduced to the practice of regional anesthesia mostly in the last two decades. Ultrasound did not gain as much popularity as the nerve stimulation until a decade ago because of the simplicity, accuracy and portability of the nerve stimulator. Ultrasound is now available in most academic centers practicing regional anesthesia and is a popular tool amongst trainees for performance of nerve blocks. This review article specifically discusses the role of ultrasonography for deeply situated nerves or plexuses such as the infraclavicular block for the upper extremity and lumbar plexus and sciatic nerve blocks for the lower extremity. Transitioning from nerve stimulation to ultrasound-guided blocks alone or in combination is beneficial in certain scenarios. However, not every patient undergoing regional anesthesia technique benefits from the use of ultrasound, especially when circumstances resulting in difficult visualization such as deep nerve blocks and/or block performed by inexperienced ultrasonographers. The use of ultrasound does not replace experience and knowledge of relevant anatomy, especially for visualization of deep structures. In certain scenarios, ultrasound may not offer additional value and substantial amount of time may be spent trying to find relevant structures or even provide a false sense of security, especially to an inexperienced operator. We look at available literature on the role of ultrasound for the performance of deep peripheral nerve blocks and its benefits.
PMCID: PMC3145343  PMID: 21808644
20.  Association of facet tropism with lumbar disc herniation 
European Spine Journal  2012;22(5):1045-1052.
Facet tropism is defined as asymmetry between left and right facet joints and is postulated as a possible cause of disc herniation. In the present study, the authors used a 3-T MRI to investigate the association between facet tropism and lumbar disc herniation at a particular motion segment. They also examined whether the disc herniated towards the side of the more coronally oriented facet joint.
Sixty patients (18–40 years) with single level disc herniation (L3–L4, L4–L5, or L5–S1) were included in the study. Facet angles were measured using MRI of 3-T using the method described by Karacan et al. Facet tropism was defined as difference of 10° in facet joint angles between right and left sides. Normal disc adjacent to the herniated level was used as control. We also examined if disc herniated towards the side of more coronally oriented facet.
Twenty-five herniations were at L4–L5 level and 35 at L5–S1. Statistical analysis was performed using the Fischer Exact Test. At L4–L5 level, 6/25 cases had tropism compared to 3/35 controls (p = 0.145). At L5–S1 level, 13/35 cases had tropism as compared to 1/21 controls (p = 0.0094). Of 19 cases having tropism, the disc had herniated towards the coronally oriented facet in six (p = 0.11).
The findings of the study suggest that facet tropism is associated with lumbar disc herniation at the L5–S1 motion segment but not at the L4–L5 level.
PMCID: PMC3657057  PMID: 23242621
Facet tropism; Lumbar disc herniation; Facet asymmetry; Magnetic resonance imaging
21.  Popliteal catheter placement utilizing ultrasound needle guidance system 
While ultrasound (US)-guided placement of peripheral nerve blocks is rapidly gaining popularity, expert practitioners agree that two of the most significant barriers to safety and efficacy are keeping the needle tip within the image and unintentional probe movement during the procedure.1 In addition, placing a nerve catheter past the needle tip under direct US observation requires two practitioners: one to hold the US probe and needle and another to advance the catheter. We present a case of a needle guidance system that attaches to the ultrasound probe and facilitates in-plane imaging. It enables a single practitioner to successfully execute a popliteal sciatic nerve block and visualize catheter placement. Therefore, a needle guidance system may represent an additional modification to ultrasound imaging that increases both time efficiency as well as safety.
PMCID: PMC3417947  PMID: 22915868
needle guidance system; popliteal sciatic nerve catheter; ultrasound
22.  Quantitative evaluation of the echo intensity of the median nerve and flexor muscles of the forearm in the young and the elderly 
The British Journal of Radiology  2012;85(1014):e140-e145.
Musculoskeletal structures often appear brighter on imaging in the elderly, which makes it difficult to accurately delineate a peripheral nerve during ultrasound-guided regional anaesthetic procedures. The echo intensity of skeletal muscles is significantly increased in the elderly. However, there are no data comparing the echo intensity of peripheral nerves in the young and the elderly, which this study was designed to evaluate.
13 healthy, young volunteers (aged <30 years) and 11 elderly patients (aged >60 years) who were scheduled to undergo orthopaedic lower limb surgery were recruited. The settings of the ultrasound system were standardised and a high-frequency linear array transducer was used for the scan. A transverse scan of the median nerve (MN) and the flexor muscles (FMs) at the left mid-forearm was performed and three video loops of the ultrasound scan were recorded for each subject. Still images were captured from the video loops and normalised. Computer-assisted greyscale analysis was then performed on these images to determine the echo intensity of the MN and the FMs of the forearm.
The echo intensity of the MN and FMs of the mid-forearm was significantly increased in the elderly (p<0.005). There was also a reduction in contrast between the MN and the adjoining FM in the elderly (p=0.04).
Under the conditions of this study, the MN and the FMs in the forearm appeared significantly brighter than those in the young, and there was a loss of contrast between these structures in sonograms of the elderly.
PMCID: PMC3474090  PMID: 22010029
23.  Ultrasound-guided Lateral Femoral Cutaneous Nerve Block in Meralgia Paresthetica 
The Korean Journal of Pain  2011;24(2):115-118.
Meralgia paresthetica is a rarely encountered sensory mononeuropathy characterized by paresthesia, pain or sensory impairment along the distribution of the lateral femoral cutaneous nerve (LFCN) caused by entrapment or compression of the nerve as it crossed the anterior superior iliac spine and runs beneath the inguinal ligament. There is great variability regarding the area where the nerve pierces the inguinal ligament, which makes it difficult to perform blind anesthetic blocks. Ultrasound has developed into a powerful tool for the visualization of peripheral nerves including very small nerves such as accessory and sural nerves. The LFCN can be located successfully, and local anesthetic solution distribution around the nerve can be observed with ultrasound guidance. Our successfully performed ultrasound-guided blockade of the LFCN in meralgia paresthetica suggests that this technique is a safe way to increase the success rate.
PMCID: PMC3111560  PMID: 21716611
lateral femoral cutaneous nerve; meralgia paresthetica; ultrasound
24.  The Importance of Needle Echogenity in Ultrasound Guided Axillary Brachial Plexus Block: A Randomized Controlled Clinical Study 
Objective: In this study we aimed to compare the echogenic needles and the nerve stimulation addition to non-echogenic needles in ultrasound guided axillary brachial plexus block for upper extremity surgery.
Methods: 90 patients were enrolled to the study. The patients were allocated into three groups randomly: Group E (n=30): ultrasound guided axillary block using echogenic needle, Group N (n=30): ultrasound guided axillary block using non-echogenic needle, Group NS (n=30): ultrasound guided axillary block using non-echogenic needle with nerve stimulator assistance. Duration of block procedure, mean arterial pressure, heart rate, pulse-oximetry, onset time of sensory and motor block, duration of sensory and motor block, time to first analgesic use, total need for analgesics, postoperative pain scores, patient and surgeon satisfaction scores were recorded.
Results: Duration of block procedure values were lower in group E and NS, sensory and motor block durations, were significantly lower in group N. Sensorial and motor block onset time values were found lower in group NS but higher in group N. Patient and surgeon satisfaction scores were found lower in group N.
Conclusion: We conclude that ultrasound guided axillary block may be performed successfully using both echogenic needles and nerve stimulation assisted non-echogenic needles.
PMCID: PMC3714386  PMID: 23869186
ultrasound; nerve stimulator; echogenity; needle; axillary nerve blockade
25.  Musculoskeletal Sonopathology and Ultrasound-Guided Regional Anesthesia 
HSS Journal  2010;7(1):64-71.
The use of real-time ultrasound guidance has revolutionized the practice of regional anesthesia. Ultrasound is rapidly becoming the technique of choice for nerve blockade due to increased success rates, faster onset, and potentially improved safety. In the course of ultrasound-guided regional anesthesia, unexpected pathology may be encountered. Such anomalous or pathological findings may alter the choice of nerve block and occasionally affect surgical management. This case series presents a variety of musculoskeletal conditions that may be encountered during ultrasound-guided regional anesthesia practice.
PMCID: PMC3026115  PMID: 22294960
anesthesia; ultrasound; regional anesthesia

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