POINT OF CARE ULTRASOUND FOR DIAGNOSING SHOULDER DISLOCATION
Usually when a patient presents to the emergency department with acute shoulder pain they go through an Xray exam. According to a research team from University of California, Irvine, ultrasound can offer comparable results more quickly without the need for ionizing radiation.
Acute shoulder dislocations are a common occurrence in the ER. Generally, shoulder dislocations are anterior (over 95%), when the shoulder bone (humerus) is displaced forward, separating from the glenohumeral joint. The study included 84 patients, whose shoulders were scanned using ultrasound. The results showed 100% sensitivity and specificity for diagnosing acute shoulder dislocations.
"We believe that ultrasound is an effective alternative to Xray in the diagnosis of shoulder dislocations," said Alex Trinh, an undergraduate medical student at the university, who presented his findings at the recent American Institute of Ultrasound in Medicine (AIUM) annual meeting in Orlando, FL.
The study set out to identify not only sensitivity, specificity and accuracy, but also to come up with standardized criteria for diagnosing shoulder dislocation with ultrasound. It focused on a sample group of patients presenting with symptoms of acute shoulder pain, and after having gone through an Xray exam, a researcher asked permission to perform a posterior, transverse ultrasound. Eighty four shoulders were scanned in the study, which included 19 anterior dislocations and 65 normal shoulders.
This study highlighted clear benefits of ultrasound, like lower time expenditure, lower workload on ER departments and nonexistent radiation exposure. But it should be noted that there are serious limitations, the biggest being that inferior and posterior dislocations are more difficult to diagnose with ultrasound because the head of the shoulder bone would be behind the glenoid rim. Although most dislocations are anterior in nature, healthcare professionals need to take everything into account before sending the patient for an ultrasound exam as opposed to an Xray exam.
Ultrasound scans of normal (left) and anteriorly dislocated shoulder (right). The humeral head is located posterior to the glenoid rim in the normal shoulder. In the anterior dislocation, the humeral head is anterior to the glenoid rim.