The Case

A 52-year-old male with a history of dyslipidemia presents to the emergency department after sustaining an injury to his left (nondominant) shoulder after colliding with another player during a soccer game. On examination, there is a loss of the normal rounded appearance of the shoulder. You suspect the patient may have a shoulder dislocation. He has no history of shoulder dislocations.

Background

Shoulder dislocations are common in the emergency department. Emergency physicians frequently perform pre- and post-reduction X-rays for these patients. Some previous studies question whether these X-rays are necessary, especially in patients without direct trauma and a history of recurrent dislocations.^1,2

Point-of-care ultrasound (POCUS) has been shown in previous studies to be sensitive and specific for diagnosing shoulder dislocations.^3,4 This application can potentially reduce radiation exposure, cost, and time to diagnosis. However, prior studies on the use of POCUS for shoulder dislocations have used a variety of scanning techniques, and some have utilized as few as two sonographers.⁴

Clinical Question

Should you use POCUS to diagnose shoulder dislocations instead of an X-ray?

Reference: Secko MA, Reardon L, Gottlieb M, et al. Musculoskeletal ultrasonography to diagnose dislocated shoulders: a prospective cohort. Ann Emerg Med. 2020;S0196-0644(20)30008-1.

• Population: Adults with suspected shoulder dislocations.
• Exclusion: Patients with multiple traumatic injuries, decreased level of consciousness, or hemodynamic instability.
• Intervention: Pre- and post-reduction POCUS utilizing a posterior approach in which the probe traces along the scapular spine toward the glenohumeral joint (see original article for details).
• Comparison: X-rays pre- and post-reduction.
• Outcomes:
  • Primary Outcome: Diagnostic accuracy of POCUS for shoulder dislocations.
  • Secondary Outcomes: Presence or absence of fracture, time from triage to POCUS exam compared to X-ray, time from POCUS exam initiation to diagnosis, determination of glenohumeral distance of nondislocated and dislocated shoulders, and sonographer confidence in diagnosis.

Authors’ Conclusions

“A posterior approach point-of-care ultrasonographic study is a quick and accurate tool to diagnose dislocated shoulders. Ultrasonography was also able to accurately identify humeral fractures and significantly reduce the time to diagnosis from triage compared with standard radiography.”

Ann Emerg Med. 2020 Feb 25. doi: 10.1016/j.annemergmed.2020.01.008. © ACEP
Ultrasonographic images of the shoulder girdle, using a curvilinear probe demonstrating the normal anatomy of the left glenohumeral joint (A), a left anterior dislocation of the shoulder with humeral head displaced anterior to the glenoid (B), and a right posterior shoulder dislocation with the humerus displaced posterior to the glenoid (C). The adjacent images correspond to the measurement of the glenohumeral distance, indicated by the red arrows.

Key Results

The study enrolled 65 patients with a median age of 40 years. Fifty-eight percent were male, 49 percent had a dislocation (one inferior, two posterior, and 29 anterior), and 32 percent had a previous dislocation.