I, also, found it extremely interesting. Back in 1995 I had a plate and 7 screws put in my right ankle. The plate and six of the screws were removed a year later - the plate is now on my key ring.

On Barbaro's X-Ray, you can see a couple of small pieces of bone that are just 'there', not screwed or anything. I had a few like that, and eventually new callus formed and the pieces were integrated with the rest of the bone.