Hip Labral Tear - Cortisone injection required before surgery?

I'm in the middle of finding out whether I have a hip labral tear or not - the MRI is tomorrow. Based on my symptoms and lack of response to PT so far, my bet is on them finding a tear. I think the MRI injection will also include a lidocaine injection to the labrum itself - the pain will temporarily be gone if the labrum is the issue.

According to my orthopedist, if a tear is found, the next step is to have a cortisone injection to the hip to take the pain away. If/When the pain comes back once the injection wears off, then we talk surgery. However, he also said that he doesn't have much luck with the cortisone injection being successful in young, active people (not super-young anymore, but definitely active!).

My question is: has anyone gone straight from the MRI/lidocaine to surgery? Good idea? Bad idea? Is the cortisone really a required step, or is he  practicing 'defensive medicine', to make sure he covers all bases before surgery?

It's not that I don't trust the doctor (he came highly recommended from two separate sources and performs plenty of hip arthrograms), although I will certainly practice due diligence and get a second opinion, but if I'm going to end up in surgery, I'd rather get it over with!

Thanks for the help!