Research has demonstrated that many individuals with Crohnâs ileitis share a genetic mutation that may play a significant role in disease development. A hypersensitive immuno-response to a pathogenic presence, such as bacteria, within the gastrointestinal tract is also suspected of contributing to the disease's onset.
Secondary osteoarthritis occurs less frequently than primary (also known as idiopathic) osteoarthritis. Primary osteoarthritis means that there is no known cause for the joint breakdown.
Answer: When we use the term primary osteoarthritis, we mean that we don't know the reason for it. In other words, most people who develop osteoarthritis, we don't really know the cause. Secondary osteoarthritis means that we do have an associated reason -- another form of arthritis, an injury or a congenital abnormality, for instance, are examples of secondary osteoarthritis.