Ultrasound-guided suprascapular nerve block: a correlation with fluoroscopic and cadaveric findings

Image-guided peripheral nerve interventions- applications and techniques

Interventional radiology continues to be at the forefront of acute and chronic pain management. Our unique imaging expertise and ability to target difficult to reach structures allows for the continuous development of new ways to treat a variety of pain generators. In addition, the advent of thermal ablation techniques and technologies has provided a unique opportunity to offer patients more durable and predictable options to treat their pain. This is particularly important during the opioid epidemic, as multiple local and international governmental bodies push for physicians to create ways to manage pain while reducing the need for long-term opioid dependence. This article aims to review various image-guided techniques and tools for the treatment of pain related to peripheral pain generators, with a focus on the extremities, lumbosacral and pelvic region, and the chest wall. For each target and pathology, we will discuss general etiology, anatomy, procedural approach, and briefly evaluate the supporting literature in each clinical situation.

Assessment of 2 distinct anatomical landmarks for suprascapular nerve injection: a cadaveric study

BACKGROUND

The suprascapular nerve block (SSNB) is a commonly used procedure for the management of pain in various shoulder pathologies. Both image-guided and landmark-based techniques have been utilized successfully for SSNB, though more consensus is needed regarding the optimal method of administration. This study aims to evaluate the theoretical effectiveness of a SSNB at 2 distinct anatomic landmarks and propose a simple, reliable way of administration for future clinical use.

METHODS

Fourteen upper extremity cadaveric specimens were randomly assigned to either receive an injection 1 cm medial to the posterior acromioclavicular (AC) joint vertex or 3 cm medial to the posterior AC joint vertex. Each shoulder was injected with a 10 ml methylene blue solution at the assigned location, and gross dissection was performed to evaluate the anatomic diffusion of the dye. The presence of dye was specifically assessed at the suprascapular notch, supraspinatus fossa, and spinoglenoid notch to determine the theoretic analgesic effectiveness of a SSNB at these 2 injection sites.

RESULTS

Methylene blue diffused to the suprascapular notch in 57.1% of the 1-cm group and 100% of the 3-cm group, the supraspinatus fossa in 71.4% of the 1-cm group and 100% of the 3-cm group, and the spinoglenoid notch in 100% of the 1-cm group and 42.9% of the 3-cm group.

CONCLUSION

Given its superior coverage at the more proximal sensory branches of the suprascapular nerve, a SSNB injection performed 3 cm medial to the posterior AC joint vertex provides more clinically adequate analgesia than an injection site 1 cm medial to the AC junction. Performing a SSNB injection at this location allows for an effective method of anesthetizing the suprascapular nerve.

Ultrasound-Guided Suprascapular Nerve Block at Suprascapular Notch-Do We Really Target Suprascapular Notch or Not? Where Is Our Real Target?

Ultrasound (US)-guided suprascapular nerve block (SSNB) is a widely used procedure and while describing the US-guided SSNB in the suprascapular notch, the suprascapular fossa is often visualized and injection is performed in that location. Although it can be done in both location, to inject the right area, the terminology should be settled and the visualization of these areas which are unclear and confusing in the literature should be clarified. In this sense, we showed the course of the nerve on a cadaver and briefly describe a protocol to correctly visualize the suprascapular notch with US.

Successful Glenohumeral Shoulder Reduction With Combined Suprascapular and Axillary Nerve Block

BACKGROUND

Anterior glenohumeral dislocation is a common injury seen in the emergency department (ED) that sometimes requires procedural sedation for manual reduction. When compared with procedural sedation for dislocation reductions, peripheral nerve blocks provide similar patient satisfaction scores but have shorter ED length of stays. In this case report, we describe the first addition of an ultrasound-guided axillary nerve block to a suprascapular nerve block for reduction of an anterior shoulder dislocation in the ED.

CASE REPORT

A 34-year-old man presented to the ED with an acute left shoulder dislocation. The patient was a fit rock climber with developed muscular build and tone. An attempt to reduce the shoulder with peripheral analgesia was unsuccessful. A combined suprascapular and axillary nerve block was performed with 0.5% bupivacaine, allowing appropriate relaxation of the patient's musculature while providing excellent pain control. The shoulder was then successfully reduced without procedural sedation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Procedural sedation for reduction of anterior shoulder dislocations is time consuming, resource intensive, and can be risky in some populations. The addition of an axillary nerve block to a suprascapular nerve block allows for more complete muscle relaxation to successfully reduce a shoulder dislocation without procedural sedation.

Osseous suprascapular canal: rare variant that would hinder suprascapular nerve block and posterior surgical approach

PURPOSE

To report atypical anatomical variation of an osseous suprascapular canal, and to elaborate on its clinical significance as a potential anatomical factor that could obscure a direct posterior surgical approach and suprascapular nerve block.

METHODS

Osteological observational study of the scapula with emphasis on the suprascapular space. The pool of investigated sample size was collectively 768 specimens composed of 529 adult dry scapulae (240 paired, 289 un-paired), 54 children dry scapulae, 135 wet scapulae observed during cadaveric dissections, 47 retrospective 3D CT reconstructions, and 3 retrospective full sequence shoulder MRI. The two reported cases came from the 240 (120 skeleton) observed paired scapulae. Furthermore, the osseous suprascapular canal was examined by X-rays and its internal path was exposed by CT sections. A narrative review was conducted to investigate any relevant reports on the subject matter.

RESULTS

Two left dry bone scapulae with unilateral osseous suprascapular canal were found. The incidence of this atypical morphology of an osseous canal is probably five cases reported in three studies including this cases study.

CONCLUSIONS

The reported cases aid in explaining additional possible anatomical factors that could lead to below threshold anesthetic effect in posterior suprascapular nerve block procedures. Therefore, it is more practical to visualize the suprascapular canal by some imaging method before attempting to blindly access the suprascapular nerve in nerve block or posterior surgical approach due to the rare potential existence of an ossified barrier hindering the procedure.

LEVEL OF EVIDENCE

V Basic Science Research.

Randomized controlled trial of suprascapular nerve blocks for subacute adhesive capsulitis

BACKGROUND

Shoulder pain and loss of function remain a therapeutic challenge in adhesive capsulitis. Suprascapular nerve blocks, a common treatment in adhesive capsulitis, are considered a safe and effective method for the resolution of pain and restoration of shoulder range of motion (ROM). To our knowledge, no data are available on the use of suprascapular nerve blocks in adhesive capsulitis in the subacute phase.

AIM

The aim of this study was to compare the efficacy of ultrasound-guided suprascapular nerve blocks versus saline injections for treating adhesive capsulitis in the subacute phase.

DESIGN

Randomized double-blinded controlled trial; level of evidence 2.

SETTING

Out-patient consultation of Physical and Rehabilitation Medicine in a general hospital.

POPULATION

Thirty-five patients with subacute adhesive capsulitis.

METHODS

Patients were randomly allocated to receive either 3 successive (1-week interval) ultrasound-guided suprascapular nerve blocks with ropivacaine 5 mL 2 mg/mL (intervention group) or ultrasound-guided injections of 5 mL sterile saline solution (NaCl 0.9%) (control group), at the floor of the suprascapular fossa. Primary outcome was shoulder function assessed by the Constant-Murley Score. Secondary outcomes were shoulder ROM and shoulder pain intensity. Assessments were performed before each injection and 4 weeks after the last injection.

RESULTS

A significant increase of Constant-Murley Score (P<0.001), increase of shoulder ROM (all directions: P<0.011) and decrease of pain (P<0.001), were observed over time in both study groups. However, no significant differences were observed between the intervention and the control group.

CONCLUSIONS

Three successive suprascapular nerve blocks did not provide a better outcome than saline injections on shoulder function, ROM, and pain in subacute adhesive capsulitis. These negative findings warrant some considerations on the natural history of adhesive capsulitis, as well as timing, type, and placebo effects of injections.

CLINICAL REHABILITATION IMPACT

The current place of suprascapular nerve blocks in the treatment strategy of adhesive capsulitis needs to be rediscussed.

Peripheral neuropathic pain

Neuropathic pain (NP) can have either central nervous system causes or ones from the peripheral nervous system. This article will focus on the epidemiology, classifications, pathology, non-invasive treatments and invasive treatments as a general review of NP involving the peripheral nervous system. NP has characteristic symptomatology such as burning and electrical sensations. It occurs in up to 10% of the general population. Its frequency can be attributed to its occurrence in neck and back pain, diabetes and patients receiving chemotherapy. There are a wide range of pharmacologic options to control this type of pain and when such measures fail, numerous interventional methods can be employed such as nerve blocks and implanted stimulators. NP has a cost to the patient and society in terms of emotional consequences, quality of life, lost wages and the cost of assistance from the medical system and thus deserves serious consideration for prevention, treatment and control.

Surgical anesthesia for proximal arm surgery in the awake patient

This education article discusses a combination of brachial plexus and peripheral nerve blocks aimed at providing complete surgical anesthesia to the proximal arm, while consistently avoiding diaphragmatic paresis. This type of approach may be warranted in patients with respiratory compromise of any etiology. In these settings awake surgery is recommended to preserve respiratory function and at the same time minimize the risk of infection of the healthcare team by avoiding the aerosol-generating medical procedures associated with general anesthesia.

Proximal vs Distal Approach of Ultrasound-guided Suprascapular Nerve Block for Patients With Adhesive Capsulitis of the Shoulder: Prospective Randomized Controlled Trial

OBJECTIVES

To evaluate the early clinical outcomes of ultrasound (US)-guided suprascapular nerve block (SSNB) using a proximal approach compared with a distal approach for outpatient treatment of adhesive capsulitis.

DESIGN

Randomized controlled trial.

SETTING

Outpatient clinic PARTICIPANTS: Participants (N=47) with symptomatic adhesive capsulitis.

INTERVENTIONS

Participants were randomly assigned to either US-guided SSNB using a proximal approach (n=23, proximal group) or a distal approach (n=24, distal group).

MAIN OUTCOME MEASURES

The primary outcome measure was the visual analog scale (VAS) for pain at week 12. Secondary outcomes included the American Shoulder Elbow Surgeon's (ASES) score, University California Los Angeles score, Short Form-36 mental and physical component summaries, and range of motion. All patients completed clinical follow-up at 2, 6, and 12 weeks after treatment. On US images, depth and insertion angle of needle during injection were measured.

RESULTS

The VAS significantly improved in both groups at week 12. After treatment, no significant differences were found in early clinical outcomes (weeks 2, 6, and 12) between groups (all P>.05), except that ASES at 2 weeks showed a significantly higher score in the distal group than in the proximal group (87.1±4.8 and 83.0±6.3, respectively; P=.014). The mean depth and insertion angle of needle was significantly lower (depth: 13.4±3.9 and 30.6±4.3 mm, respectively; P<.001; insertion angle: 19.6°±6.4° and 38.7°±5.8°; P<.001) in the proximal group than in the distal group.

CONCLUSIONS

This study demonstrated that proximal approach of US-guided SSNB provided favorable short-term outcomes of pain and functional improvement and that outcomes were comparable to those of the distal approach in adhesive capsulitis. The suprascapular nerve was located more superficially and easily identified in the proximal approach, suggesting that this method might improve the accuracy of injection.

Ultrasound-guided pulsed radiofrequency neuromodulation of the suprascapular nerve in partial rotator cuff tears

Background/Aim

Pulsed radiofrequency (PRF) of the suprascapular nerve has been shown to be effective in the treatment of chronic shoulder pain. Ultrasound (US) guidance has gained popularity in regional blocks recently. This study aims to investigate the efficacy of suprascapular nerve pulsed radiofrequency under the guidance of ultrasonography.

Materials and methods

This retrospective study included patients treated with PRF of the suprascapular nerve with a diagnosis of partial rotator cuff tears. The patients were assessed with a numeric rating scale (NRS), the Shoulder Pain and Disability Index (SPADI), and a Likert patient satisfaction score before the treatment and 3 weeks and 6 months following the treatment.

Results

A total of 31 patients was included in the study. The patients’ mean age was 66.8 ± 13.3 years. The mean scores of the NRS, SPADI, and Likert scale before the procedure (7.32 ± 1.1, 69.0 ± 8.5, 1.6 ± 0.6) and at 3 weeks (2.9 ± 2.1, 32.1 ± 17.20, 4 ± 1.2) and 6 months (3.2 ± 2.6, 33.9 ± 20.8, 3.8 ± 1.2) after the procedure were evaluated. We observed significant improvement in NRS, SPADI, and Likert scores at 3 weeks and 6 months following the treatment (P < 0.001).

Conclusion

The study demonstrated that US-guided suprascapular nerve PRF achieves good pain relief and functional improvement in patients with partial rotator cuff tears for at least 6 months.

Distal suprascapular nerve block-do it yourself: cadaveric feasibility study

BACKGROUND

A bone landmark-based approach (LBA) to the distal suprascapular nerve (dSSN) block is an attractive "low-tech" method available to physicians with no advanced training in regional anesthesia or ultrasound guidance. The primary aim of this study was to validate the feasibility of an LBA to blockade of the dSSN by orthopedic surgeons using anatomic analysis. The secondary aim was to describe the anatomic features of the sensory branches of the dSSN.

MATERIALS AND METHODS

An LBA was performed in 15 cadaver shoulders by an orthopedic resident. Then, 10 mL of methylene blue-infused 0.75% ropivacaine was injected around the dSSN; 2.5mL of red latex solution was also injected to identify the position of the needle tip. The division and distribution of the sensory branches that originate from the suprascapular nerve were described.

RESULTS

The median distance between the dSSN and the site of injection was 1.5 cm (0-4.5 cm). The most common injection site was at the proximal third of the scapular neck (n = 8). Fifteen dSSNs were stained proximal to the origin of the most proximal sensory branch. All 15 dSSNs gave off 3 sensory branches that innervated the posterior glenohumeral capsule, the subacromial bursa, and the coracoclavicular and acromioclavicular ligaments.

CONCLUSIONS

An LBA for anesthetic blockade of the dSSN by an orthopedic surgeon is a simple, reliable, and accurate method. Injection close to the suprascapular notch is recommended to involve the dSSN proximally and its 3 sensory branches.

Efficacy of suprascapular nerve block compared with subacromial injection: a randomized controlled trial in patients with rotator cuff tears

HYPOTHESIS

We aimed to compare the clinical efficacy of a suprascapular nerve block (SSNB) versus subacromial injection (SA) for outpatient treatment of patients with symptomatic rotator cuff tears in a double-blinded, randomized controlled trial using sealed-envelope randomization.

METHODS

A total of 42 participants with symptomatic partial- and full-thickness rotator cuff tears quantified by ultrasound or magnetic resonance imaging received either an ultrasound-guided SSNB or SA. The primary outcome measure was shoulder function measured by the modified Constant-Murley (CM) score and the secondary outcome was the pain score measured by a visual analog scale at 2, 6, and 12 weeks after injection.

RESULTS

We analyzed 43 shoulders (27 in male patients, 62.2%). The mean age was 65.2 years (standard deviation [SD], 11.9 years). Of the shoulders, 22 (51.2%) underwent SAs and 21 (48.8%) underwent SSNBs. Continuous variables were analyzed by an independent t test (2 tailed), and nominal data were analyzed by the Fisher exact test (1 sided). At 6 weeks, the mean change from the baseline CM score was significantly higher in the SSNB group than in the SA group (14.3 [SD, 18.1] vs 3.0 [SD, 12.8]; P = .048). At 12 weeks' follow-up, the SSNB group had a significantly higher CM score than the SA group (57.6 [SD, 10] vs 44.6 [SD, 16]; P = .023) and greater improvement from the baseline CM score (23.4 [SD, 17.5] vs 7.8 [SD, 16.5]; P = .014). At 12 weeks, the visual analog scale score was significantly better in the SSNB group than in the SA cohort (9.9 [SD, 3.3] vs 7.3 [SD, 4.3]; P = .03).

CONCLUSIONS

This study demonstrates that an SSNB resulted in better pain and functional results than an SA at 6 and 12 weeks for symptomatic rotator cuff tears.

“Pseudo-suprascapular notch”: is it a sonographic trap in suprascapular nerve block?

Background and objectives

The aim of the study was to describe the radiological anatomy of the pseudo-suprascapular notch—a structure localized at the floor of the supraspinatus fossa, just below the true suprascapular notch. In sonographic examination, it may imitate the suprascapular notch leading to misidentification of these structures.

Methods

Ultrasound assessment of the suprascapular notch region was performed in 100 patients who underwent chest CT due to other indications. The presence of the suprascapular notch and the pseudo-suprascapular notch was evaluated together with their maximal width and depth using both techniques. The correlation between the dimensions of these two notches was assessed.

Results

The pseudo-suprascapular notch was recognized in 82 patients. In four of them the suprascapular notch could not be visualized in ultrasound due to obscuring clavicle. In all cases the pseudo-suprascapular notch contained a small artery. In comparison to the suprascapular notch, the pseudo-suprascapular notch was significantly narrower and shallower, except for 10 cases with vestigial suprascapular notch where the pseudo-suprascapular notch was the only hollow in this region. The dimensions of both structures did not correlate with each other. Finally, the pseudo-suprascapular notch did not present any significant asymmetry (p=0.1185) or sexual dimorphism (43 women vs 38 men, p=0.2025).

Conclusions

The pseudo-suprascapular notch is a hollow for nutrient vessels that can be mistaken for the regular suprascapular notch in cases of difficult sonographic navigation.

Post-operative analgesia for shoulder arthroscopic surgeries: A comparison between inter-scalene block and shoulder block

Background and Aims

Shoulder arthroscopic surgeries can produce intense post-operative pain. Inter-scalene block (ISB) provides good analgesia after shoulder surgery, but concerns over its associated risks have prompted the search for alternatives. Shoulder block (SHB), which includes suprascapular block along with axillary nerve (AN) block, was recently proposed as an alternative to ISB, but evidence of its efficacy is conflicting. The aim of our study was to compare SHB with ISB in shoulder surgery for post-operative analgesia.

Methods

A total of 76 patients scheduled for shoulder arthroscopic surgery were equally divided into 2 groups of 38 patients each: ISB group and SHB group. Both the nerve blocks were achieved by using ultrasound and a nerve stimulator. Visual analogue scale (VAS) scores were evaluated at 1, 4, 6, 12 and 24 h post-operatively. The time to first analgesia request, total analgesic requirement for 24 h post-operatively, patient satisfaction and any complications were recorded.

Results

SHB provided equivalent analgesia to ISB in terms of post-operative VAS scores. Time to first analgesic request was 6.2 ± 1.3 h in ISB group and 5.9 ± 1.2 h in SHB group, which was not statistically significant. Complications like subjective dyspnoea and weakness of arm were significantly higher in ISB group compared to SHB group. Patient satisfaction scores were also significantly higher in SHB group compared to ISB group.

Conclusion

SHB is as effective as ISB for post-operative pain relief and with fewer complications due to selective blockade of suprascapular and axillary nerves.

Suprascapular Nerve Blockade for Postoperative Pain Control After Arthroscopic Shoulder Surgery: A Systematic Review and Meta-analysis

Background:

Regional nerve blocks are commonly used to manage postoperative pain after arthroscopic shoulder procedures. The interscalene brachial plexus block (ISB) is commonly used; however, because of the reported side effects of ISB, the use of a suprascapular nerve block (SSNB) has been described as an alternative strategy with fewer reported side effects.

Purpose:

To examine the efficacy of SSNB for pain control after shoulder arthroscopy compared with ISB as well as anesthesia without a nerve block.

Study Design:

Systematic review; Level of evidence, 1.

Methods:

Three databases (PubMed, MEDLINE, and EMBASE) were searched on April 20, 2018, to systematically identify and screen the literature for randomized controlled trials (RCTs). A meta-analysis of standard mean differences (SMDs) was performed to pool the estimated effects of the nerve blocks.

Results:

The search identified 14 RCTs that included 1382 patients, with a mean age of 54 years (SD, 13 years). The mean follow-up time was 3 days (range, 24 hours to 6 weeks). Postoperative pain control was significantly more effective in the SSNB groups compared with the control groups within 1 hour (SMD, –0.76; 95% CI, –1.45 to –0.07; P = .03) and 4 to 6 hours (SMD, –0.81; 95% CI, –1.53 to –0.09; P = .03) postoperatively. However, pain control was significantly less effective in the SSNB groups compared with ISB within 1 hour (SMD, 0.87; 95% CI, 0.28 to 1.46; P = .004). No major complications were noted in the SSNB groups, and minor complications such as hoarseness and prolonged motor block were significantly less common for SSNB compared with ISB.

Conclusion:

Although not more efficacious than ISB in terms of pain control for patients undergoing shoulder arthroscopy, SSNB provides significantly improved pain control in comparison with analgesia without a nerve block. Moreover, few major and minor complications are associated with SSNB reported across the literature.

Comparative study of anatomical landmark-guided versus ultrasound-guided suprascapular nerve block in chronic shoulder pain

Background:

Suprascapular nerve block (SSNB) is an effective method for the treatment of shoulder disorders. The present study was conducted to evaluate and compare the effectiveness of SSNB under ultrasonographic guidance with anatomical landmark-guided (LMG) technique in the treatment of chronic shoulder pain.

Materials and Methods:

A total of fifty patients with shoulder pain were enrolled in the present prospective randomized study. Patients in Group I (n = 25) received SSNB using the anatomical LMG as technique described by Dangoisse, in whom a total of 6 ml of drug (5 ml of 0.25% bupivacaine and 40 mg methylprednisolone) was injected. Group II patients (n = 25) were given SSNB using the ultrasound guidance with the same amount of drug. Pain was measured using visual analog scale (VAS), range of motion and Shoulder Pain and Disability Index (SPADI) were recorded. Observations were recorded before the block, immediately after the block, and 1 and 4 weeks after the block.

Results:

There was no statistically significant difference between the VAS score, range of motion and SPADI before the procedure (P > 0.05) in both the groups. Both the groups showed statistically similar improvement of VAS, range of motion and SPADI at 4-week (P > 0.05) follow-up. In Group I, VAS decreased from baseline value of 6.64 ± 1.50–2.04 ± 0.94 at 4 weeks (P < 0.001). In Group II, the VAS decreased from 6.92 ± 1.00 to 1.84 ± 1.03 at 4 weeks (P < 0.01).

Conclusion:

In our study, both the techniques have produced comparable relief of pain, improvement in shoulder movement, and decreased SPADI 4 weeks after the block.

The Influence of Suprascapular Notch Shape on the Visualization of Structures in the Suprascapular Notch Region: Studies Based on a New Four-Stage Ultrasonographic Protocol

Evaluation of the morphology of the suprascapular notch region is important from a clinical point of view because it is the most common site of suprascapular nerve compression and injury. A group of 120 patients underwent ultrasound examination of the suprascapular notch region according to our original four-stage "step-by-step" protocol. The notches were classified based on their morphology and measurements like maximal depth (MD) and superior transverse diameter (STD) as follows: type I-MD is longer than STD, type II-MD and STD are equal, type III-STD is longer than MD, and in type IV/V-notches only the bony margin was visualized without depression. Both suprascapular notches were fully visualized in 115 of 120 patients. The type III suprascapular notch was the most prevalent (64.2%), followed by type IV/V (18.7%), type I (11.1%), and type II (6.0%). Color Doppler analysis allowed the suprascapular artery to be recognized in all visualized notches. The suprascapular vein was visible in 176 notches and the suprascapular nerve in 150. Notches containing both suprascapular nerve and vein were significantly wider and shallower than average. As the suprascapular artery is the most easily recognised structure in the area, it may serve as a useful landmark of the suprascapular notch.

Ultrasound-guided interventional procedures around the shoulder

Ultrasound is an established modality for shoulder evaluation, being accurate, low cost and radiation free. Different pathological conditions can be diagnosed using ultrasound and can be treated using ultrasound guidance, such as degenerative, traumatic or inflammatory diseases. Subacromial-subdeltoid bursitis is the most common finding on ultrasound evaluation for painful shoulder. Therapeutic injections of corticosteroids are helpful to reduce inflammation and pain. Calcific tendinopathy of rotator cuff affects up to 20% of painful shoulders. Ultrasound-guided treatment may be performed with both single- and double-needle approach. Calcific enthesopathy, a peculiar form of degenerative tendinopathy, is a common and mostly asymptomatic ultrasound finding; dry needling has been proposed in symptomatic patients. An alternative is represented by autologous platelet-rich plasma injections. Intra-articular injections of the shoulder can be performed in the treatment of a variety of inflammatory and degenerative diseases with corticosteroids or hyaluronic acid respectively. Steroid injections around the long head of the biceps brachii tendon are indicated in patients with biceps tendinopathy, reducing pain and humeral tenderness. The most common indication for acromion-clavicular joint injection is degenerative osteoarthritis, with ultrasound representing a useful tool in localizing the joint space and properly injecting various types of drugs (steroids, lidocaine or hyaluronic acid). Suprascapular nerve block is an approved treatment for chronic shoulder pain non-responsive to conventional treatments as well as candidate patients for shoulder arthroscopy. This review provides an overview of these different ultrasonography-guided procedures that can be performed around the shoulder.

Clinical evaluation of the shape of the suprascapular notch--an ultrasonographic and computed tomography comparative study: Application to shoulder pain syndromes

The most common site of suprascapular nerve compression and injury is the suprascapular notch. The aim of this study was to assess the sensitivity and specificity of sonography in determining the type of suprascapular notch (SSN). Thirty randomized patients (60 upper extremities) underwent USG examination of the shoulder area. The results were further compared with three-dimensional reconstructions of the scapulae obtained through CT examination to place the SSNs within a fivefold classification. For identification of type I, the sensitivity was 73.3% and the specificity 97.8%. For identification of type III, the values was 96.9% and 85.7%, respectively. Type II was not found in USG examination. Discrimination between type IV and V was not possible. The mean distance between the line connecting the edges of the SSN and the skin was 38 mm in right-handed patients and 34 mm in ambidextrous subjects. Ultrasonographic examination of the SSN is characterized by high specificity for type I, and high sensitivity for type III SSN. Discrimination between type IV and V of the SSN is not recommended based on sonographic evaluation.

Ultrasound-guided block of the suprascapular nerve - a volunteer study of a new proximal approach

BACKGROUND

The standard approach for the suprascapular nerve block is deep in the supraspinous fossa. However, with this approach, the suprascapular nerve is difficult to visualize by ultrasound. The aim of this study was to describe a new method to visualize and selectively block the suprascapular nerve in a more superficial and proximal location.

METHODS

Twelve healthy volunteers were included. We located the brachial plexus in transverse section with ultrasound, and by longitudinal slide, we identified the departure of the suprascapular nerve from the superior trunk. The suprascapular nerve was followed under ultrasound visualization into the subclavian triangle under the inferior belly of the omohyoid muscle. We performed in-plane ultrasound-guided selective suprascapular nerve block by injecting 1 ml of lidocaine, 20 mg/ml close to the nerve. Nerve identification was aided by nerve stimulation. We assessed sensory and motor block of the suprascapular, axillary, radial, median, and ulnar nerves before, 15 and 30 min after performing the block.

RESULTS

Eight volunteers demonstrated a selective suprascapular nerve block. Three had block failure and one volunteer did not receive the intervention.

CONCLUSIONS

We describe a new ultrasound-guided low-volume local anaesthetic technique to selectively block the suprascapular nerve. The potential clinical role of this new approach remains to be determined.

The suprascapular vein: a possible etiology for suprascapular nerve entrapment and risk of complication during procedures around the suprascapular foramen region

INTRODUCTION

Nerve can be compressed when traveling through any osteo-fibrous tunnel. Any eventual anatomic structure limiting this passage increases the risk of neuropathy. During dissection of the shoulder region we recognized a vein travelling on the inferior border of the suprascapular notch together with the suprascapular nerve. The aim of this work was to evaluate the morphological characteristics of this vein in cadaveric material.

MATERIALS AND METHODS

The suprascapular notch (SSN) region was dissected in 60 cadaveric shoulders. The course, number and diameter of nerve and vessels in the suprascapluar notch region were evaluated. Length, proximal and distal width of the superior transverse scapular ligament were measured. Photographic documentation was taken to evaluate the suprascapular nerve passage area.

RESULTS

The vein identified was named as the suprascapular notch vein. It was present in 58.3% of shoulders. In 11 specimens, it was double. Its mean diameter was 1.7 mm (SD 0.7 mm) and did not correlate with the suprascapular nerve passage area. A suprascapular notch vein co-occurred more often with the anterior coracoscapular ligament (ACSL). In comparison with the SSN without the ACSL, it has a significantly greater diameter (2 mm; SD 0.7 mm vs 1.5 mm; SD 0.6 mm, respectively; P=0.021).

CONCLUSIONS

The suprascapular notch vein was a common structure that did not replace the suprascapular vein. Its presence correlated with the occurrence of the ACSL and was independent of body side, STSL type and SSN type.

TYPE OF STUDY

Observational anatomic study.

Preoperatıve ultrasound-guıded suprascapular nerve block for postthoracotomy shoulder paın

BACKGROUND

Acute postthoracotomy pain is a well-known potential problem, with pulmonary complications, ineffective respiratory rehabilitation, and delayed mobilization in the initial postoperative period, and it is followed by chronic pain. The type of thoracotomy, intercostal nerve damage, muscle retraction, costal fractures, pleural irritation, and incision scar are the most responsible mechanisms.

OBJECTIVE

Our aim was to assess whether preoperative ultrasound suprascapular nerve block with thoracic epidural analgesia was effective for postthoracotomy shoulder pain relief.

METHODS

Thirty-six American Society of Anesthesiologist classification physical status I-III patients (2011-2012), with a diagnosis of lung cancer and scheduled for elective open-lung surgery, were prospectively included in the study. Eighteen of the patients received an ultrasound-guided suprascapular nerve block with 10-mL 0.5% levobupivacaine, using a 22-gauge spinal needle, 1 hour before operation (group S); 18 other patients had thoracic epidural analgesia only, and no nerve block was performed. Standard general anesthesia was administered. Degree of shoulder pain was assessed by a blinded observer when discharging patients from the recovery room, and thereafter at 1, 3, 6, 12, 24, 36, 48, and 72 hours on infusion at rest and 12, 24, 36, 48, and 72 hours on coughing. The same blinded observer also recorded the total amount of epidural levobupivacaine and fentanyl used by the 2 groups.

RESULTS

In the suprascapular block group, the total amount of levobupivacaine (P = 0.0001) and fentanyl (P = 0.005) used postoperatively was statistically lower than in the epidural group. Visual analogue scale measurements in the suprascapular group were statistically significantly lower at 0, 1, 3, 6, 12, 24, 36, and 48 hours than those in the epidural group, both at rest and coughing.

CONCLUSION

Postthoracotomy shoulder pain reduces patient function and postsurgical rehabilitation potential after thoracotomy, and various studies on explaining the etiology and management of postthoracotomy shoulder pain have been conducted. Theories of the etiology involved either musculoskeletal origin or referred pain. In this study, we concluded that preoperative ultrasound-guided suprascapular nerve block with thoracic epidural analgesia could achieve effective shoulder pain relief for 72 hours postoperatively, both at rest and coughing.

Ultrasonography- or electrophysiology-guided suprascapular nerve block in arthroscopic acromioplasty: a prospective, double-blind, parallel-group, randomized controlled study of efficacy

PURPOSE

To evaluate the efficacy of ultrasonography-guided (UG) and electrophysiology-guided (EG) suprascapular nerve block (SNB) for arthroscopic acromioplasty with regard to pain relief.

METHODS

A prospective, double-blind, randomized controlled clinical trial was performed from June 2007 to April 2010. Patients who were scheduled for elective arthroscopic acromioplasty and who met the inclusion criteria were assigned to 1 of 2 experimental groups (UG or EG SNB) or to 1 blind group (using anatomic landmarks). Before surgery, an SNB was performed with either ultrasonographic or electrophysiologic guidance or with no assistive devices (blind). Variables were collected at 4, 24, 48, and 72 hours postoperatively.

RESULTS

Sixty-three patients were initially enrolled in the study, but 11 dropped out for various reasons. In the UG group at 4 hours, the visual analog scale score at rest (30 ± 12.0 v 39 ± 9.9 for EG group and 41 ± 11.8 for blind group) and when the patient was moving (42 ± 15.2 v 52 ± 11.5 for EG group and 53 ± 12.6 for blind group) was significantly decreased compared with the EG and blind groups (P < .05). Opioid consumption during the first 24 hours was significantly reduced in the UG and EG groups (4.3 ± 1.9 mg and 3.8 ± 2.3 mg, respectively) compared with the blind group (5.1 ± 2.2 mg) (P < .05). The visual analog scale score at rest and when the patient was moving; the pain score on the University of California, Los Angeles questionnaire; and the activities of daily living score on the American Shoulder and Elbow Surgeons questionnaire in the EG and UG groups improved more than the values in the blind group over the follow-up intervals (P < .05). Morphine consumption in the EG and UG groups by the first, second, and third days was significantly smaller than that in the blind control group (P < .05).

CONCLUSIONS

UG and EG SNB can reduce pain and painkiller consumption for up to 72 hours postoperatively. Ultrasonographic or electrophysiologic guidance is more effective than the blind method of SNB.

LEVEL OF EVIDENCE

Level I, randomized controlled trial with significant difference.

Ultrasound-guided pain interventions - a review of techniques for peripheral nerves

Ultrasound has emerged to become a commonly used modality in the performance of chronic pain interventions. It allows direct visualization of tissue structure while allowing real time guidance of needle placement and medication administration. Ultrasound is a relatively affordable imaging tool and does not subject the practitioner or patient to radiation exposure. This review focuses on the anatomy and sonoanatomy of peripheral non-axial structures commonly involved in chronic pain conditions including the stellate ganglion, suprascapular, ilioinguinal, iliohypogastric, genitofemoral and lateral femoral cutaneous nerves. Additionally, the review discusses ultrasound guided intervention techniques applicable to these structures.

Suprascapular nerve block: a narrative review

Suprascapular nerve blockade (SSNB) is a simple and safe technique for providing relief from various types of shoulder pain, including rheumatologic disorders, cancer, and trauma pain, and postoperative pain due to shoulder arthroscopy. Posterior, superior, and anterior approaches may be used, the most common being the posterior. Recently, an ultrasound-guided approach has been described. In this review, the basic anatomy of the suprascapular nerve will be described. The different techniques of SSNB and indications for SSNB will be discussed. The complications of SSNB and outcomes of SSNB on the management of acute and chronic shoulder pain will be reviewed.

Ultrasound-guided peripheral nerve blockade of the upper extremity

PURPOSE OF REVIEW

Is ultrasound guidance changing the practice of upper extremity regional anesthesia? This review will aim to describe the findings published in the literature during the previous 18 months.

RECENT FINDINGS

In some approaches to brachial plexus blockade, local anesthetic volumes may be reduced without deterioration of analgesic effect. However, even 10 ml of local injected into the interscalene space may result in diaphragmatic paresis. High-resolution ultrasonography has revealed anatomical variations of C5, C6 and C7 nerve roots in almost half of the patients examined, without negative block effectiveness. The addition of dexamethasone may prolong analgesia after single-shot interscalene and supraclavicular blocks. Insertion of brachial plexus perineural catheters using ultrasound guidance can be successful and provides better postoperative analgesia than single-shot blocks for up to 24 h postoperatively. Infraclavicular catheters provide superior analgesia when compared with supraclavicular catheters. Multiple-site injections of local offer no advantage over a single-site injection during an infraclavicular block. Ultrasound guidance compared with neurostimulation may reduce patient discomfort during axillary blocks compared with neurostimulation. Intra-epineural injections are common during an interscalene blockade, but the incidence of neurological injury remains low. There is an ongoing debate on the effectiveness and safety of ultrasound-guided intra-epineurial injections.

SUMMARY

Current literature suggests a reduction of the volume of local anesthetics used for ultrasound-guided upper extremity blockades. Dexamethasone may prolong duration of brachial plexus blocks and more frequent use of perineural catheters is encouraged. Controversy over intra-epineurial injections exists and requires additional large-scale studies.

Ultrasound brachial plexus anesthesia and analgesia for upper extremity surgery: essentials of our current understanding, 2011

PURPOSE OF REVIEW

Ultrasound-guidance is gaining tremendous popularity. There is growing evidence of value with emphasis on clinical relevance, but can ultrasound-guidance scientifically warrant changing the practice of upper extremity regional? The literature is searched to describe findings where ultrasound may reduce complication rates, reduce block performance times, and improve block efficacy and quality.

RECENT FINDINGS

Ultrasound examination identified variations in anatomical positioning of C5-C7 roots in approximately half of all patients despite no deleterious effects on block efficacy. Anesthetic volumes in brachial plexus blockade may be reduced without compromise of effectiveness. However, even with reduced volumes injected into the interscalene space, respiratory compromise from effect(s) on the phrenic nerve may result in hemi-diaphragmatic paresis. Ultrasound-guidance may reduce discomfort during axillary block placement compared with neurostimulation or parasthesia. Nerve catheters may be highly effective and provide prolonged analgesia compared with single-shot injections. Infraclavicular catheters result in improved analgesia compared with supraclavicular catheters and multiple injections of local provide no advantage over single-shot infraclavicular blockade. Dexamethasone combined with local may extend analgesia following a single-injection interscalene or supraclavicular block. During interscalene blockade, intraepineurial injections may occur, but incidence of nerve injury remains low. Therefore, debate continues about intraepineurial injections.

SUMMARY

Intraepineurial injection requires additional investigation. Conclusions have suggested reducing typical volumes (40  ml) of local with ultrasound-directed upper extremity blockade. Increased use of perineural catheters is being advocated for prolonged analgesia, but risk-to-benefit consequences need to always be considered.

Treating frozen shoulder with ultrasound-guided pulsed mode radiofrequency lesioning of the suprascapular nerve: two cases

OBJECTIVE

Many approaches to treatment of frozen shoulder, or adhesive capsulitis, including use of steroid injections, provide only short-term relief. We present a method for pulsed mode radiofrequency (PRF) lesioning of the suprascapular nerve using ultrasound guidance in patients with severe pain from frozen shoulder.

DESIGN

Patients with frozen shoulder were treated by using real-time, high-resolution ultrasound guidance to facilitate PRF lesioning of the suprascapular nerve.

SETTING AND PATIENTS

Two patients with frozen shoulder of a tertiary hospital were reported.

MEASURES

Pain intensity and shoulder movement before and after procedure were recorded. Results.  In the two cases presented, both patients experienced pain relief and increased shoulder flexibility for 5-6 months.

CONCLUSION

Ultrasound can not only quickly and effectively identify the suprascapular notch and nerve, but also helps the operator manipulate and advance the needle to a more precise position.