Shoulder stiffness: diagnosis.
BACKGROUND: Pain and stiffness of the shoulder is a common complaint, particularly in the 40-80 years age group. There are several causes of painful, stiff shoulders, but the most common cause in the fifth decade of life is idiopathic capsulitis ('frozen shoulder'). OBJECTIVE: This article summarises the functional anatomy of the shoulder joint, the pathology of the conditions that lead to shoulder stiffness, and methods to differentiate them. DISCUSSION: Clinical history and examination is effective in differentiating rotator cuff tears, impingement and frozen shoulder. Restriction of glenohumeral joint motion, particularly in external rotation, with no abnormality on X-ray is strongly suggestive of the diagnosis of frozen shoulder. Plain true anteroposterior X-rays are important to identify glenohumeral joint arthritis. Ultrasound is often helpful for confirming or denying rotator cuff tears when there is doubt on the clinical examination.