During aspiration of joint (in this case an elbow joint) you can use  fluid to wash out smaller loose parts in the joint. This case is of soccer goal keeper with chronic inflammation of elbow that was limiting him during any kind of exercise.

Loose bodies in the joint support inflammation by mechanically interfering with joint biomechanics. If the parts are small we can pull them out by simple aspiration. In animated gif, you see small parts of the cartilage floating in a syringe.