Shoulder pain from eating hamburgers?! Find the Dx with POCUS

While eating a hamburger, an 85 year-old obese woman felt a sudden and sharp pain in her right shoulder. Although she has a past history of rhematoid arthritis, she had no prior shoulder pain. She was also taking coumadin for atrial fibrillation. On arrival, she was unable to move her arm. Several diagnoses come to mind. Septic joint, acute gout, tendinopathy, etc. And how big was that hamburger she was holding?! With POCUS, I could see the subdeltoid bursa filled with fluid containing echogenic material. Interesting. I did an ultrasound-guided tap which yielded clotted blood. She was diagnosed with spontaneous hemorrhagic bursitis. She did very well with conservative treatment. The video shows a lateral view of the shoulder.  The deltoid muscle is in the near field.  The humerus is in the far field.  The bursa is in between.  Effusions in the subdeltoid bursa are often an indirect sign of tendon injury.  But in this case, it was simply a spontaneous hemorrhage related to the coumadin and possibly her rheumatoid arthritis.  See the illustration at the bottom for the relevant anatomy.