Pseudogout of the acromioclavicular joint: report of two cases and review of the literature.

Although calcium pyrophosphate dehydrate (CPPD) deposition disease, including pseudogout, is a relatively common disease affecting the major joints, especially the knee, pseudogout in the acromioclavicular (AC) joint is very uncommon. We describe two cases of acute pseudogout attacks of the AC joint in elderly patients. Radiological findings showed chondrocalcinosis in the AC joints. Microscopically, aspirated articular synovial fluid demonstrated CPPD crystals. Conservative therapy with non-steroidal anti-inflammatory drugs completely resolved all symptoms within 1 week.