When a patient goes to the hospital with sudden pain and limited movement in the shoulder joint, the doctor tells the patient that there is calcification in the tendon called “rotator cuff” in the shoulder joint. The pain is caused by the calcification secondary to the impingement of the shoulder joint and the increased pressure on the tendon. What is this about? The literature reports that approximately 2-7% of patients with shoulder pain are caused by calcification of the tendon within the rotator cuff. The majority of calcifications are in the supraspinatus tendon. The cause of tendon calcification is not known. Once calcification of the supraspinatus tendon in the rotator cuff occurs, the early stages of calcification and the period of calculus resorption can cause secondary impingement syndrome and pain in the shoulder joint due to increased pressure on the tendon. Depending on the early stage of calcification formation or absorption, fluoroscopic needle aspiration, extracorporeal shockwave therapy, and minimally invasive arthroscopic treatment can be used to treat this condition. At present, arthroscopic treatment is becoming more and more popular because it allows observation of the entire rotator cuff and joint and allows for targeted treatment. Yilihamu, Department of Orthopedics, Second Affiliated Hospital of Xinjiang Medical University Typical case: A 32-year-old male was admitted to the hospital with a complaint of shoulder pain. Calcification of the supraspinatus tendon was found on radiograph. After arthroscopic shoulder debridement of the calcifications, the joint pain improved significantly.