Snapshot A 70-year-old man presents to the emergency department for severe left knee pain. Medical history is significant for hyperparathyroidism managed with bisphosphonates. On physical exam, the left knee is erythematous, warm, enlarged, and tender to palpation. Radiography of the affected joint demonstrates chondrocalcinosis. Joint aspiration demonstrates a leukocyte count of 2800/mm3 with 50% polymorphonuclear cells. Polarized microscopy shows weakly positively birefringent rhomboid crystals. Introduction Clinical definition login to view 1 more bullet Epidemiology login to view 2 more bullets Etiology login to view 1 more bullet Pathogenesis login to view 3 more bullets Associated conditions login to view 6 more bullets Prognosis login to view 3 more bullets Presentation Symptoms login to view 15 more bullets Imaging Radiography login to view 5 more bullets Studies Arthrocentesis login to view 6 more bullets Differential Gout login to view 3 more bullets Treatment Conservative login to view 3 more bullets Medical login to view 10 more bullets Complications Joint damage