Damage from an injury to the hip, such as hip dislocation, can create loose bodies of cartilage covered pieces of bone which float around the joint. However, single or multiple loose bodies can also be caused in a number of other ways. Synovial chondromatosis, for example, is a condition where the lining of the joint is abnormal and makes large numbers of small lumps of cartilage which can float around causing pain when they jam in the joint. These lumps of cartilage, or bone and cartilage, can gradually grow larger within the joint. These can jam and cause locking symptoms and severe pain, and may cause joint inflammation (synovitis). Over time, they may cause damage to the joint cartilage and lead to the development of osteoarthritis.

Loose bodies can be removed arthroscopically and the synovitis treated.

Single loose bodies most often do not recur, but synovial chondromatosis may recur.