A Case of Crystal-Proven Calcium Pyrophosphate Deposition Disease in the Sternoclavicular Joint

Calcium pyrophosphate deposition disease (CPPD) is an important cause of crystalline arthritis commonly involving the knees and wrists, although many joints can be affected. Calcium pyrophosphate deposition disease of the sternoclavicular (SC) joints has been described rarely and historically has either been unconfirmed or reliant on surgical pathology for diagnosis. We describe a patient with episodic pain and swelling of the SC joint with corresponding chondrocalcinosis on computed tomography imaging and subsequent image-guided aspiration that confirmed presence of CPPD crystals. To our knowledge, this is the first reported case of crystal-proven CPPD by arthrocentesis of the SC joint.