Thyroid and shoulder diseases: the bases of a linked channel.

The association between thyroid disorders and musculoskeletal diseases has long been suspected, but it is still debated whether they have a role in the pathogenesis of shoulder diseases. In vivo and in vitro studies describe the role of thyroid hormones in bone, cartilage and tendon biology. Retrospective studies and case reports suggest that thyroid diseases should be considered as risk factors and hold prognostic value in some of the most common causes of shoulder pain. Thus, it is advisable to search for underlying thyroid disorders in these patients. The pathophysiologic mechanisms by which thyroid hormone imbalance affects the onset, progression and response to treatment of these diseases are yet to be thoroughly defined and demand further studies.