Compressive, invasive referred pain to the shoulder.

The painful shoulder can be the presenting complaint of a wide variety of local, as well as systemic, problems. Compression of the brachial plexus or occlusion of the subclavian vessels caused by narrowing of the thoracic outlet is best diagnosed by a thorough history and physical examination, and by performing the appropriate test maneuvers. Patients who do not respond to an exercise program to strengthen the shoulder girdle may require surgical excision of the first rib to enlarge the thoracic outlet. Referred pain in the shoulder originating from the cervical spine or peripheral nerves can be determined by cervical spine roentgenograms and nerve conduction tests. Neoplasms and parenchymal disease of the lung, and infections of the pleural and subdiaphragmatic areas can refer pain to the shoulder through the phrenic nerve. For those patients with persistent shoulder pain and no discernible musculoskeletal abnormalities who do not respond to standard therapeutic measures, another source of the shoulder pain should be sought.