History of Enthesitis

Historically the enthesis was considered to be a focal point where ligaments or tendons where inserted to the bone.

Physicians have long recognised the importance of isolated enthesitis such as inflammation at the Achilles tendon insertion or "Achilles tendonitis" or "Achilles enthesitis". Another example of a common enthesis disorder is pain in the sole of the foot at the heel that is termed plantar fasciitis. However, the full spectrum of enthesis related disorders was not appreciated beyond these isolated clinical entities.

It is now clear that enthesitis can occur in many clinically inaccessible sites including the spine and around the ribs and chest and within joints.

In particular, inflammation within bone at insertions points is a key feature of enthesitis and this can manifest as bone pain.

Crucially the "blast zone" associated with enthesitis is not confined to the insertion but afflicts the adjacent tissues. All of the tissues that function together at the insertion are known as the enthesis organ.

This is they key structure for understanding the Rheumatic Diseases.