Primarily an illness of middle-aged males and elderly adults<unk>  in females usually occurs only after menopause<unk>  is most common form of inflammatory joint disease in men >40yr
Presence of crystals does not exclude septic arthritis<unk>  in females usually occurs only after menopause
Trauma
Surgery
Medication (allopurinol, thiazide/loop diuretics, ASA)
Alcohol consumption
Meat/Seafood consumption
Dehydration
Lower body temperature
Gout and pseudogout
Acute osteoarthritis
Boxer's fracture
Avascular necrosis
Colles' fracture
Crystal-induced 
Salter-Harris fractures
Gonococcal arthritis, arthritis-dermatitis syndrome