section name header

Pathophys and Cause ⬇

Cause:Calcium pyrophosphate crystals

Pathophys:Poly ingestion of crystals results in enzyme release in the joint and subsequent inflammation

Epidemiology ⬆ ⬇

Increased incidence in hemochromatosis, hypothyroidism, hypo-Mg2+, hyperparathyroidism, gout, RA, DJD

Signs and Symptoms ⬆ ⬇

Sx:Acute arthritis

Si:Knee > mcp > wrist > shoulder

Complications ⬆ ⬇

r/o calcium oxalate deposition in renal failure (Ann IM 1982;97:36)

Lab and Xray ⬆ ⬇

Lab:

Joint fluid:With a polarizing scope, calcium pyrophosphate crystals (rhomboid, positively birefringent in red filter) (Gout), may be small and require oil immersion lens to see

Xray:

Chondrocalcinosis, semilunar calcifications of joint cartilages, esp of wrists and knees; r/o hypomagnesemia (Nejm 2009;360:71)

Treatment ⬆

Rx: Indomethacin; local steroid joint injections or systemic steroids