Inflammation of the entheses can cause new bone tissue to form. That new bone tissue gets in the way of normal movement and function -- like a bone spur on your heel. Enthesitis is common in some forms of arthritis, including psoriatic arthritis and ankylosing spondylitis. It also can happen in some children with juvenile idiopathic arthritis (also known as juvenile rheumatoid arthritis). It's not usually linked to osteoarthritis or adult rheumatoid arthritis, but people with those conditions can have it.