See what he or she has to say, and tell him/her why you're still having a problem and see what he/she recommends. If, after doing so, you feel like you've lost your trust in him/her, i would then get a third opinion, and go with the majority.
If there is a way to get you out of pain and walking fine again, wouldn't that be preferable to a law suit?
Just so you know, in most states (i'm only familiar with ny law), you need three things for medical malpractice:
1) negligence: not all bad outcomes are the result of negligence. Even the best doctors, under the best conditions, with the best patient, etc. Have a bad outcome risk. In a medical malpractice suit, the burden of proof is on you to prove negligence.
2) damages: even in the presence of negligence, with no damages, there is no case. Even if we were to assume your fracture
was fixated in a negligent manner, if, in time, you're fine and can walk with no pain, there are no damages.
3) proximate cause: the damages have to be the direct result of the negligence, not something that would have occurred regardless.
Every state has a statute of limitations, a time by which you must file a claim before you're precluded from doing so. It's usually a couple of years.
I would again suggest you try your best to resolve your problem. You'll still have time to file a suit if you're left in pain, assuming something was done negligently, and not a bad result in the presence of an otherwise well-performed reduction.
I hope this helps, and i hope you feel better.