A loose body is a free floating fragments of cartilage and/or bone within a joint. If left untreated or removed, damage may occur to the affected joint. Loose bodies are most commonly found in the knee, shoulder and elbow.

Loose bodies are classified by three types: fibrinous, cartilaginous, and osteocartilaginous.

Fibrinous loose bodies are the result of bleeding within the joint and may appear in individuals with tuberculosis, rheumatoid arthritis, and osteoarthritis.

Cartilaginous loose bodies, consisting of cartilage, are most often the result of injury or osteoarthritis.

Osteocartilaginous loose bodies, consisting of both bone and cartilage, may result from fractures, inflammation, osteoarthritis, or benign tumors.

Patients report pain, swelling, a grinding sound, and locking of the affected joint.