Which is a worse injury a shoulder dislocation or a broken collar bone?

Dislocation: Shoulder dislocation is worse because if it does not heal then it can lead to recurrent dislocation. The collar bone fractures heal in 99% cases & most of the heal with conservative management.

Different: Shoulder dislocation involves the joint. May recur. Fx clavicle usually will heal, maybe with surgery.

It depends.: It depends on the specifics of both injuries. But, generally speaking, the vast majority of collarbone fractures heal uneventfully, and do not cause any permanent impairment to the shoulder.