How effective is shoulder manipulation under anesthesia?

Very effective: Anesthesia for any joint manipulation allows the surgeon to move the joint around much more because it will not be limited secondary to pain. More scar tissue can be broken up this way.

So- so: The best current treatment for a frozen shoulder that fails conservative treatment is an arthroscopic capsular release. There is less risk of breaking your humerus from a manipulation.

Good: The anesthetic allows the surgeon to break up adhesions in your shoulder from scar tissue that you would not permit them to do while you are awake. In this way they can greatly improve range of motion.