Fibrodysplasia ossificans progressiva (FOP), is a rare disease of the connective tissue. A mutation of the body's repair mechanism causes fibrous tissue (including muscle, tendon, and ligament) to be ossified (turned to bone) when damaged. In many cases they can cause joints to become permanently frozen in place. The growths cannot be removed with surgery because such removal causes the body to "repair" the area of surgery with more bone.

IFOPA - International Fibrodysplasia Ossificans Progressiva Association - Support group for families. Information about the condition, treatment, and research efforts.
Meta Description: [ The IFOPA is dedicated to improving FOP awareness & education, encouraging communication, and supporting medical research. ]
McKay Orthopaedic Research Laboratory - Summaries of current research projects at the University of Pennsylvania.
SFGate - San Francisco Chronicle article describes the disease, includes anecdotes about the lives of several patients.