Shoulder pain: a diagnostic dilemma.

The etiology of shoulder pain can usually be placed into one of five categories: fracture and/or contusion, shoulder separation involving the clavicle, instability of the glenohumeral joint, impingement syndrome involving the rotator cuff or biceps tendinitis, and frozen shoulder. Non-shoulder pathology, such as cervical strain, thoracic outlet syndrome and referred pain from phrenic nerve irritation, should be excluded when evaluating patients presenting with shoulder pain. After inflammatory or infectious arthritis has been ruled out, the history should point to either acute trauma or an overuse injury. Physical examination may provide information about neurovascular status, palpable tenderness, range of motion, strength, instability and impingement. Radiographic studies are usually indicated in patients with a history of trauma, but they are often not necessary in the initial evaluation of overuse injuries. Magnetic resonance imaging and arthrograms should be reserved for patients who have not responded to six to eight weeks of conservative treatment and are candidates for surgery.