I remember being taught as a medical student that clavicle fractures could be treated conservatively.  A direct quote was "if both ends of the clavicle are in the same room it will heal".

Though conservative treatment with a sling for 6 weeks with early pendulum ROM exercises for the shoulder is appropriate for the vast majority of clavicle fractures surgery should be considered for those that have:

1. An open fracture
2. Significant angulation with tenting of the skin
3. Midshaft fractures that have overlap or displacement greater than 1 cm.
4. Displaced fractures of the distal clavicle [high rate of non-union]
5. Surgery can also be beneficial to those that do a lot of lifting or want to return to work as quick as possible.