The Case: 25 year old man with no past medical history presents to the ED with acute left shoulder pain. He was playing soccer, jumped up for a header, and fell onto his left side 1 hour ago. On exam, his left upper extremity is adducted, internally rotated, and flexed at the elbow. He is neurovascularly intact, and range of motion is significantly limited secondary to pain. He otherwise has no obvious humerus deformity and no pain with palpation of humerus, elbow, forearm or wrist. You suspect a shoulder dislocation. Radiology is called to conduct bedside x-ray prior to reduction. However, they are busy in trauma with a multi-victim motor vehicle accident and say it may take up to 1 hour to obtain x-rays given they are short staffed today. So, you reach for your ultrasound…
Why It Matters: Shoulder dislocations are a common presentation to the emergency department and account for approximately 200,000 visits annually [1]. As ultrasound becomes more widely available throughout emergency departments, its use has become a novel approach for accurate and more timely diagnosis of shoulder dislocations. In a multicenter, prospective, cohort study, ultrasound was found to have 100% sensitivity and 100% specificity in diagnosing shoulder dislocations. Ultrasound was also noted to be 43 minutes faster for diagnosing shoulder dislocations compared to standard radiograph approach. Furthermore, ultrasound can also be used to confirm adequate reduction, reducing the need for post reduction films.
How To Do It: First place your monitor in front of the patient, and stand behind the patient (Figure 1). Find the scapular spine and place the probe parallel and just below the scapular spine with the indicator pointing to the patients left. Begin to move the probe laterally until the glenoid and humeral head are seen together. You may have to fan or change depth to optimize the picture. Given that this is a posterior approach, an anterior dislocation has the appearance of the humeral head moving away from the probe or deeper on the screen (Figure 2). After successful reduction, repeat your ultrasound to confirm successful reduction (Figure 3).
Figure 1: Ideal positioning of probe and screen to optimize patient and user comfortability
Figure 2: Ultrasound using posterior approach demonstrating anterior dislocation of left shoulder.
Figure 3: Ultrasound using posterior approach demonstrating adequate post reduction of left shoulder
Authored by Ramin Chitsaz, MD
References
Secko MA, Reardon L, Gottlieb M, Morley EJ, Lohse MR, Thode HC Jr, Singer AJ. Musculoskeletal Ultrasonography to Diagnose Dislocated Shoulders: A Prospective Cohort. Ann Emerg Med. 2020 Aug;76(2):119-128. doi: 10.1016/j.annemergmed.2020.01.008. Epub 2020 Feb 25. PMID: 32111508.