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

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.

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.