A single-view posterior POCUS can reliably identify anterior shoulder dislocation using the **Glenohumeral Separation Distance (GhSD)**—a simple measurement of the posterior alignment of the humeral head and glenoid.
How to Use It
Place a linear probe transversely on the posterior shoulder.
Identify the most posterior aspect of the humeral head and glenoid.
Measure the vertical offset (GhSD):
GhSD > 0 cm ? Normal alignment
GhSD < 0 cm ? Anterior dislocation
GhSD = 0 cm ? Borderline; treat as suspicious
Clinical Implications
Even minimally trained operators achieved 100% sensitivity and specificity in detecting anterior dislocation using this method.
POCUS can:
Enable rapid diagnosis when radiography is delayed.
Confirm reduction immediately at bedside, especially valuable when sedation is used.
Potentially reduce ED length of stay and radiation exposure.
Limitations to Consider
Not validated for posterior dislocations.
Does not assess associated injuries (fractures, Hill-Sachs, Bankart lesions).
Findings based on novice sonographers; performance among clinicians likely equal or better but still needs broader validation.
Single-center, small convenience sample.
No posterior dislocations occurred; technique not validated for them.
Novice sonographers could not be fully blinded to shoulder appearance.
