The painful shoulder. Zeroing in on the most common causes.

Most shoulder problems seen by the primary care physician involve impingement syndrome or problems at the acromioclavicular joint. Despite the complexity of the structures involved, most of these conditions can be diagnosed and treated without difficulty. MRI or other imaging studies are seldom needed but can be used to confirm a questionable diagnosis. Referral to an orthopedic surgeon is appropriate if shoulder problems persist for 3 to 6 months or if there is evidence of a medium or large rotator cuff tear, severe shoulder stiffness, or a complicated fracture.