My son broke his wrist last summer, in two different places. It's called a comminuted fracture. He had to have surgery to realign the bones and then had a plate put in to keep everything in place. He also wore a cast for a long time. Recovery was long and painful, but thankfully he's fine now.
Most wrist fractures don't need surgery. But sometimes the fracture is very severe or the bone breaks and protrudes from skin. So surgery becomes necessary.