Shoulder Pseudodislocation Associated with Calcific Tendinitis/Bursitis and Diagnosed by Point of Care Ultrasound.

Background: Shoulder pseudodislocation, or "drooping shoulder," presents with acute pain and deformity of the joint, with radiographs demonstrating inferior subluxation of the humeral head relative to the glenoid fossa. The diagnosis must be made promptly and distinguished from true glenohumeral dislocation, both to avoid unnecessary attempts at closed reduction and to facilitate investigation of the underlying cause, which may include septic arthritis, hemarthrosis, or other emergent etiologies. Point-of-care ultrasound (POCUS) may be useful in the evaluation of emergency department (ED) patients with suspected pseudodislocation.

Case Report: A 50-year old female presented to the ED with an acutely painful and deformed shoulder but atypical history and physical examination. Initial radiography appeared to show a glenohumeral dislocation, but POCUS, done to guide intra-articular lidocaine injection, led to recognition of pseudodislocation and subsequent diagnosis of calcific tendinitis/bursitis, a condition not previously associated with inferior humeral subluxation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Shoulder pseudodislocation must be considered in the evaluation of patients with suspected glenohumeral dislocation, but atypical features on history, physical examination, or initial plain radiography. POCUS may facilitate prompt diagnosis and identification of the underlying etiology.