Loose Body

Loose bodies (‘floating pieces’) within the knee are the end result of some other problem. They can be due to a piece of torn cartilage, joint gristle or bone that has broken free usually after trauma, a small piece of bone or gristle from an arthritic joint or from a variety of other causes (such as osteochondritis dissecans-OCD).
They cause complaints of locking and the complaints of the other main problem. The small piece may be able to be felt through the skin in several different parts of the knee at different times. The locking is ‘true locking’ where the knee jams and is very painful to move and requires a wiggle or shake of the knee to suddenly free it. This is in contrast to the ‘locking’ of an arthritic or inflamed joint, which is mainly stiffness, and difficulties easing the joint free after sleeping or prolonged sitting.
The problem of true locking should be treated by arthroscopic removal of the loose body to avoid further damage to the precious joint surface gristle.