X-ray of the right shoulder of a 48 year old patient with calcific tendinitis. Calcific tendinitis occurs when deposits of hydroxyapatite (crystalline calcium phosphate, white patches) form in a tendon, causing pain and inflammation. Here, presence of greater tuberosity of the head of humerus is seen. This usually occurs in the tendons of the rotator cuff (shoulder), but can occur in any tendon of the body. Treatment can be through limiting calcium in the diet, using a needle to break up the deposits and then syringing them out with saline, physical therapy, or surgery.