What are some of the complications arising from a scaphoid fracture?

Usually none: But a certain percentage get somethign called avascular necrosis look it up.

Non mal union: Non union it doesn't heal malunion it heals butin a poor position avn avascular necrosis of the proximal pole or segment late findings of a scaphoid non -union collapse pattern in the wrist or snac wrist cast and or surgical complications, stiffness infection bleeding nerve irritation and "wait there is more!".