2090419 Localizing Maximal Distention in the Subdeltoid Bursa by Point-Of-Care Ultrasound Alters The Ultrasound-Guided Injection Approach

Abstract

Palpation-guided corticosteroid (CS) injections are often provided from a posterior approach, aiming at the subacromial aspect of the subdeltoid bursa with varying accuracy and treatment response. Ultrasound (US) can visualize bursal fluid, thickening, tendinopathy, and tendon tears. US-guided injections are known to be accurate. Our OBJECTIVES: was to evaluate how point-of-care US affects the US-guided injection approach for treatment of shoulder pain. We retrospectively reviewed clinical and US characteristics of 67 patients with shoulder pain/impingement syndrome who received a total of 96 US-guided CS injections in an academic rheumatology US clinic. Images were obtained and interpreted by 1 expert MUS-trained rheumatologist. All images were reviewed by a 2nd US-trained physiatrist. Patients were mostly female (64.2%) with a mean age of 63.5 and BMI of 29.1. Twenty-six patients (38.8%) received prior palpation-guided injections with more than half of these patients (61.5%) reporting little to no benefit. US-guided injection approach was determined by localizing the maximal area of fluid distention or thickening of the subdeltoid bursa visualized by US, corresponding with clinical tenderness. US-guided injections were provided in the typical subacromial target, laterally over the supraspinatus tendon in 41.7% of injections; however, 58.3% of injections were targeted anterior to the acromion: anterolaterally over the subscapularis tendon (35.4%), anterolaterally over the supraspinatus tendon (20.8%) and anteriorly over the biceps tendon (2.1%). The majority of all US-guided injections (96.8%) provided improvement to complete relief immediately post-injection. Point-of-care US identified maximal distention of the subdeltoid bursa to be more commonly located anterior to the acromion rather than directly subacromial. This finding may be a reason for failed palpation-guided injections. US-guided injection approach was altered by targeting a specific location with clinical correlation. This method has the potential to improve clinical outcomes. Future prospective studies are needed.