Pyrophosphate arthropathy

Arthropathies associated with crystals deposition are acute gouty arthritis, chronic gout and chronic tophaceous gout due to monosodium urate crystals. Then there is acute pseudogout and chronic pyrophosphate arthropathy caused by calcium pyrophosphate dehydrate crystals. Acute calcific periarthritis, acute hydroxylapatite arthritis and chronic hydroxyapatite arthritis including Milwaukee-shoulder-knee syndrome are due to basic calcium-phosphate-hydroxyapatite crystals. 

A number of other crystalline arthropathies may present as gout but are not associated with hyperuricaemia. Most notably, pseudogout is due to the deposition of calcium pyrophosphate crystals. 

The deposition of crystals of monosodium urate (gout), calcium pyrophosphate dehydrate (CPPD chondrocalcinosis, pseudogout) and calcium hydroxyapatite (HADD calcifying tendinitis) within synovium, articular cartilage, fibrocartilages and para-articular soft tissues may produce a spectrum of clinical conditions ranging from asymptomatic entities to severe rapidly destructive arthropathy (Steinbach 2004 Clement et al. 2005). The accumulation of crystals takes months to years to develop and leads to the establishment of a chronic synovitis with intermittent acute flares. 

Among the degenerative arthropathies that typically involve the shoulder, there are a variety of conditions related to crystal deposition diseases, including renal osteodystrophy, milk alkali syndrome, hyper-vitaminosis D and the so-called Milwaukee shoulder syndrome . This last condition, which is also known as apatite-associated destructive arthritis, hemorrhagic shoulder or rapid destructive arthritis of the shoulder, consists of massive rotator cuff tear, osteoarthritic changes, hlood-stained noninflammatory joint effusion containing calcium hydroxyapatite and calcium pyrophosphate dihydrate crystals, synovial hyperplasia and extensive destruction... 

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