Tendonitis is a medical word used to describe inflammation of a tendon. A tendon attaches muscle to bone. Repetitive use of a muscle tendon unit and/or age or trauma can cause tendonitis. Early tendonitis can be treated with rest, ice, and anti-inflammatory medication. Refractory cases may require a cortisone injection and/or surgical intervention. Tendonitis is more common in aging athletes secondary to decreased vascularization. Sever cases of tendonitis can cause partial tearing as well as complete tearing requiring surgery.