The regeneration medicine is already upon us and it is a matter of time before limbs will be grown within weeks if not days. If we stick to the interpretation that Quran advocates cutting of hands as opposed to a financial hit, then will it still be a an exemplary punishment given the developments in Medicine?
according to this Islamic Q&A:
The thief has no right to have the amputated hand reattached, because that means that the signs of the punishment for his crime disappear, and the effectiveness of the rebuke and lesson is lost. It is contrary to the idea of punishment and example as mentioned in the verse in which Allaah says (interpretation of the meaning)
and they base this on:
[As for] the thief, the male and the female, amputate their hands in recompense for what they committed as a deterrent [punishment] from Allah. And Allah is Exalted in Might and Wise.5:38
But I don't agree with this as the following ayat says:
But whoever repents after his wrongdoing and reforms, indeed, Allah will turn to him in forgiveness. Indeed, Allah is Forgiving and Merciful.
and every verse begins with the invocation
In the name of Allah, the Beneficent, the Merciful.
Hence, other punishments are preferable when a society can afford it, that is they can be compassionate and merciful towards criminals. Its also a useful observation that when a man is in prison, he has effectively lost the use of his hands for a specified period of time - though we usually just say he's lost his freedom. Of course, if he is put in prison for life, he has effectively lost the use of his hands (and much else) for life.