There's an episode where Dr. House says that he should have amputated his leg. So why doesn't he?
Because he wanted to save his leg.
House: You asked me how I'd hurt my leg. I had a blood clot, and the muscle was dying. And I had all these doctors telling me I should amputate, and I said no, and they did this... very risky operation. I almost died.
Hanna: (shivering) But you saved your leg.
House: I wish I hadn't.
Certainly, with the benefit of hindsight House wishes that he had agreed to the amputation but at the time he wasn't to know the full ramifications of the drastic procedure he did undergo and the effects it would have on him as a person.
House: They cut out a chunk of muscle about the size of my fist, and they left me with this, mutilated, useless thing. I'm in pain... Every day. It changed me. Made me a harder person, a worse person. And now... Now I'm alone. You don't want to be like me. You’ve got a husband who loves you. You have friends. You can start a family. You have a life. And this... This is just a leg.