A loose body is a small piece of cartilage or bone that is floating within the joint. These often result from injury or severe muscle strain at the muscular insertion. Loose bodies can cause sharp pain and may even cause a person to feel their joint give way. Certain conditions such as synovial chondromatosis of the hip may cause multiple loose bodies within the joint. Loose bodies can be removed arthroscopically, alleviating the pain and feelings of catching or giving-way.
Hip arthroscopy: removal of os acetabuli: