Sounds like a Rotator Cuff Tear

Orthopedic surgeons at the Cleveland Clinic Foundation in Ohio did this study. They wanted to see how accurate office-based ultrasound studies are in finding rotator cuff tears of the shoulder.

Each patient was examined and X-rayed. Ultrasound (US) and magnetic resonance imaging (MRI) were done before surgery. Results were compared after the operation when the doctor knew for sure what the problem was.

There was no difference between US and MRI. Both were able to find the size and type of rotator cuff tear. The US wasn't as good as MRI when it came to showing if the tear was partially or fully torn.

The authors conclude that US studies of the shoulder done in the surgeon's office can help diagnose rotator cuff tears. The surgeon can look at the results of the exam, X-rays, and US to plan the best surgical approach. Failure of the US to show partial versus full tears doesn't impact the surgery.