I ask this because I legitimately don't know... I have been under the understanding that these hard-core opioids are/were intended for the treatment of the worst pain (terminal cancer patients, end of life care, etc). How or why did they end up being legitimately prescribed for more "common" pain (after surgery, back pain, etc)? Are the other options just deficient?
Simple answer of one many different ways to use it.
Let's say you're coming in for a big lung resection via thoracotomy incision (incredibly pain big ass incision along rib cage). You are going to be miserable after, bottom line. Depending on other factors, we likely would some sort of epidural catheter before surgery, the surgeon can put in a pump, or they can do nerve blocks from the inside of the chest using local anesthetics.
However, those above options may or may not give you good relief, or for medical reasons may not be used. Where I did residency, every patient who was having thoracic surgery was put on a protocol where they were given pills the morning of surgery. Tylenol, gabapentin, celebrex, and oxycontin. Relatively small doses of each for maximum synergistic benefits without side effect profile.
The wonderful thing about oxycontin, and really the only diff between it and oxycodone, is that it is sustained release over a longer period of time so you don't have to redose as often. Someone having a very long surgery or anticipated long term pain issues can be started on a longer acting/release medication so that they build up a baseline of pain control and can supplement with other immediate release pain medications as needed. Of course, these are not intended to be anything more than a few days in hospital (at most) while the patient transitions to less frequent, smaller dosed medications as pain improves.
Just an example, could give 20 more very easily.