Bro....on Monday you talked about the gym you've been going to and you're running gear. You can workout and use steroids but you're in too much pain to work your job?
Look I'm on board with fuck big companies get whatever you can out of them because they'll do the same to you but this is just hurting yourself, I could play devils advocate on their behalf but fuck them this is about your future. If you have to embellish your story to a bunch of guys on a message board which have no consequence to you then 100% your company has cause to fire you and it sounds like you're making it easy on them, also the fact that your ortho isn't backing you up is really telling on this.
You're headed the wrong way, for sure some lawyer is going to tell you all about your rights in backwards ass California and he'll be happy to drain your life savings "fighting" for you. You'll lose your job, tie up your life for 5 years at least with a legal battle, make yourself completely unemployable in the corporate world then MAYBE get a token settlement which isn't even going to come close to covering your costs let alone your future opportunity costs taken into consideration.
OR
Stop doing things to make it worse like lifting and using gear, go to your job tell them exactly what is going on and that you're willing to suck it up for a few months to keep your job. Hang tough until you can do it the right way to take away any opportunity for them to fire you with cause which is exactly what you're giving them right now. That way they will be forced to accommodate for you, but they're sure as shit not going to do that while you're using PTO to avoid going back to work. There is a path here where you can get what you want but it takes sacrifice on your end as well, you're not entitled to your job you're not irreplaceable to where you can just keep leaching out this company with no consequence.
You're young you've got a long way to establish yourself in the world and build your empire, what you're trying to do will set you back years and you will regret it. You'll be that guy that whenever someone asks what you do you'll tell them all about your little pity story of your personal injuries and how you got screwed over and now you can't get a job and have to live off the government because you're in pain and life is so hard for you the world is unfair blah blah blah.......we all know somebody like that and it's pathetic.
I know this isn't what you want to hear but this is the reality of it please don't be upset with me thinking I'm attacking you I'm just being real about, it will fuck your life up if you keep going down this path.