Loose bodies in the shoulder are pieces of torn tissue that float around the shoulder joint, and in turn cause irritation, pain, swelling and locking.
Loose bodies are typically removed arthroscopically — that is, with the aid of a small camera. A surgical instrument called a "grasper" collects and removes the loose tissue.
The orthopedics departments of John C. Lincoln Hospitals invite you to watch this overview of removal of loose bodies from the shoulder.