Loose bodies are small fragments of cartilage or bone that can form in joints; particularly the hip, knee and elbow.

Loose bodies don’t have to cause problems and they can often be stable and fixed within the joint space.  If they are free in the joint they may become trapped between the bony joint surfaces where they may give rise to twinges of pain, locking of the joint or blocked or ‘springy’ movements.

A loose body in the knee joint causes twinges of pain, swelling and the sensation of giving way.  There may also be the sensation of the knee locking but that usually passes quite quickly.  If the knee remains locked or needs manipulation to unlock the joint then an orthopaedic opinion is normally required as an arthroscopic (key hole) investigation may be indicated.  The condition is most commonly associated with osteoarthritis in the knee or a flap of cartilage within the knee may also cause similar symptoms.

Physiotherapy can help by applying a special technique that stretches through the joint to give the loose body room to move, and then applying a few sharp flicks to jolt the loose body into a more comfortable position.