My GF had her tailbone broken by her first baby 6 years ago and had a bad back from it until her second child was born 3 and a half years ago. The first birth was natural (no interventions at all) and the second was the same. I don't even think she considered elective C for the second, she just went for it. No problems with the second, it also ended up being intervention-free and her back is not nearly as bad since the second one.
If you plan to have an elective C, that's one thing, if you want a natural birth (no induction, epi etc) you really have to go into it without planning for an emergency C. I'd allow for it in the birth plan, but not structure the Plan A part around Part B. To avoid an emergency C (and there is no real reason it should get to that stage, is there? I mean, if you don't have interventions?) you really need to have faith in your body's ability to adapt for birthing (and it does!), because if you embed into your plan a blueprint for interventions, that's statistically very likely to be what you'll get, culminating in an emerg C.
So, a previously broken tail bone does not preclude you from a genuinely natural birth (if you are induced, it's not natural, even if that's the only intervention you have), in the experiences of people here and elsewhere (i.e. my friend) who have had them the first time round
Also, please don't forget to look into how the interventions affect your baby as a neonate, because they will. The interventions may help you give birth, and there is a trade-off that isn't favourable for the reason you're getting them, unfortunately. When you look into the effects on the baby you can also then embed into your plan way to counteract those effects as best as humanly possible - as was said previously, see if you can have immediate skin-to-skin contact to enhance establishment of BFing etc, or it might sway you to avoid intervention all together and go natural.
Remember that without being induced you will give your body enough time to produce natural endorphins which will assist in masking any tailbone discomfort, if any. Endorphins are only produced when adrenaline is suppressed, which means working on remaining in a relaxed state
Good luck!
Thanks for your advice Mayaness, but as i said in my first post i am unable to have a natural birth(no interventions at all - have to be induced) as it is too risky for me and the baby. The chances of having to have an emergency cs in that time period(6-24hrs depending on the anethetist) is not 100% obviously but no body can guarentee me that nothing will go wrong.

If I take my clexane injection and go into labour soon after, end up going to the hospital and somethings wrong with baby(i know its rare but it can happen) and i so happen to strike an anthetist that wont do a csection in 12-24 hours(because of legal reasons) i either lose my baby or i have a c-section and risk me hemoraging to death in theatre.
Thats not something I want in the back of my mind going into a natural labour and im already put off by my first labour as it was very very long and an awful experience. I would not go into labour with a positive attitude and i can see that leading to complications.

All the things that could go wrong in natural or induced labour are at low risk of happening but they could still happen, and if they were too occur, the out come of them happening would be worse than the outcome of a c-section.
At least I can plan for a c-section and have everything down pat and ready to go and ready to deal with any complications if they happen. And I will also know that I wont be jeopordising the long term health of me or risk losing my baby.

This may sound terrible to some people but im not worried about maybe feeling like im not bonding with my baby because of the c-section, in the fact that after my first labour because of what happened, I was unable to walk properly, i couldnt hold my baby properly to feed him because of the pain in my tailbone and my husband did everything except feed him in the 1st week and my son and are so close and have been from an early age. I never felt like I wasnt bonding with him, i knew we had a lifetime to get to know each other and what was important at the time was I get myself better. So it wont be much different to that with a c-section -maybe a little worse or better depending on the outcome.
I also think its lovely for the husband to experience some bonding time with the child as the mother has just carried them for 9 months. My husband adored the time he had with his son in the first week and I felt such a loving, family feeling seeing my baby and husband bonding so well while I recovered.

I know some people feel different and thats fine, everyone has their own opinion. I just feel this is the right choice for me and my future but its also nice to hear stories and get info from other people.
Thanks to everyone for sharing