Question
why do urate crystals collect in joint spaces in gout?

Answer
This is because your joints are lubricated with synovial fluid. When there is to much uric acid in your body then the uric acid level in your synovial fluic increases. As the synovial fluid move between your joints then crystals are formed and lodge in the joints.

Rusty
http://arthritis-symptom.com/Gout-Symptoms/gout-cause.htm