The painful shoulder syndrome is a frequent cause of visits to primary care physicians. Between 10% and 20% of the population can expect to have at least one episode of this disorder1.
The etiopathogenic mechanisms of painful shoulder have not been adequately established2,3. In some cases there are clear antecedents of mechanical overload or traumatic injury, but in others these antecedents are lacking, or the patient has no recollection of any cause that might account for the pain. In addition, the disorder is more common against a background of certain clinical entities such as diabetes, although the causes of this relationship are unknown.
Conservative approaches to treatment offers several options4. Pharmacological treatment is based mainly on nonsteroid antiinflammatories and analgesics, and on the infiltration of depot corticosteroids and anesthetics. Physiotherapy is another available option.
As yet there are no clear clinical criteria for choosing one option over another, for combining different treatments, or for deciding in which order to use different options. None of the treatments individually is infallible, and practitioners must rely on their own training and experience in deciding which option to use. Because of these uncertainties, new lines of research are being tried (and further possibilities also merit study) with the aim of developing appropriate treatments with lower risks.
Surprisingly, despite the high incidence of this disorder there are few well-structured studies that compare treatment alternatives5. The article in this issue by Pons et al. compares one treatment previously found to be superior to a placebo, i.e., local infiltration of corticosteroids6, with a newer option: nitroglycerin patches placed over the painful area. The results of their study show that nitroglycerin patches cannot be considered an additional treatment option: the hoped-for clinical benefits were not obtained, and moreover many patients abandoned treatment because of adverse effects.
