Ultrasound for Shoulder Dislocation

Shoulder Byte


Point-of-care ultrasonography for the management of shoulder dislocation in ED

American Journal of Emergency Medicine May 2016 - Pubmed Link


Background

Joint dislocations are common, and the shoulder is half of all joint dislocations. In the emergency department, we traditionally confirm the diagnosis on xray, reduce the shoulder (interscalene block anyone?), and then confirm reduction on post reduction xray films. The usual downsides of xray compared to ultrasound apply here - more time, more radiation, and having only a static image. Ultrasound potentially offers a way to diagnose shoulder dislocation, but how well does it perform in doing so?


Questions

How does POCUS compare with xray in diagnosing shoulder xray?

How does POCUS compare with xray in diagnosing fractures and verifying reduction?


Population

Prospective, observational, convenience sample

2 hospitals, one academic

Inclusion:

  • greater than 15 years old with suspected dislocation on exam

  • Only enrolled during shifts that attendings trained were working


Exclusion:

  • younger than 15 (unclear what would happen if they arrived on their 15th birthday)

  • multiple trauma

  • unstable vital signs

  • refused to consent

  • fracture diagnosis prior to POCUS

  • open dislocation

  • those in whom reduction was not accomplished


Who did the scans?

8 emergency physicians

Given special training for the study

  • 30 min lecture

  • 2 hours of practicing including diagnosing fracture in greater and lesser tubercles, humeral head, humeral neck, and glenoid rim. Also identifying hill sachs and bankart fractures.


Design

Prospective convenience sample when any of 8 study physicians available

No blinding

No Randomization


Intervention

Study patients received POCUS of the shoulder prior to xray and then again after reduction attempt.


Scan

Probe choice: In this study a high frequency linear probe was used. You can also use a curvilinear probe.

Step 1: view shaft of humerus in short axis, posteriorly.

Step 2: slide up to find humeral head

Step 3: slide laterally to view GH joint and posterior glenoid labrum

Step 4: evaluate humeral head, tuberosities and intertubercular groove by sliding around anteriorly

One Minute Ultrasound Video - Shoulder dislocation


Results

103 Patients

98 (95.1%) had dislocation


Primary Findings

POCUS for dislocation: 100% sens and 100% specific for dislocation


Secondary Findings

POCUS for fracture: 100% sensitive, 84.2% specific (only 9 fractures overall)

POCUS for reduction: 100% sensitive (*incorrectly reported in paper as 100% specific - because there were no negative xrays, there were no true negatives, can’t calculate specificity)

In this study, sonologists could not accurately determine anterior versus posterior dislocation.


Limitations

Convenience sample

High incidence of dislocation in this population

Extensive shoulder US use of study sonologists

If unsure if pathology present - instructed to rate as “pathology” --> likely attributed to high sensitivities


Take Home Points

1. Ultrasound can be used to diagnose shoulder dislocation and reduction. In this study 100% sensitive and specific.

2. With training, ultrasound can also recognize shoulder fractures with high sensitivity.


Our score

3 Probes


Cite this article as

Michael Prats, MD. Ultrasound for Shoulder Dislocation. Ultrasound G.E.L. Podcast Blog. Published on November 21, 2016. Accessed on June 17, 2019. Available at https://www.ultrasoundgel.org/7.
Published on 11/21/16 03:00 AM
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