A difficult decision that no mother should have to make

So I just got back from the Children's hospital with Angelo. Going to the doctor is nothing new for us. Angelo was born with a birth defect called Fibular Hememilia (he is missing the fibula bone in his leg). Because of this, his affected leg is a little bit shorter than his other leg, a discrepancy that will increase as he ages. He also only has 4 fingers on that foot, and 4 fingers on his right hand. This is fairly common in children with his condition. In fact, Angelo was lucky he was born with all 4 of his toes, many kids have only 1 or none at all, making walking nearly impossible. He didn't get lucky when it came to his fibular bone though. Many kids are born with shortened fibulas, but Angelo's fibular bone is absent all together. It is unknown what causes Fibular Hemmelia. Doctors believe it could be genetic, although we have no history of limb defects in our family. They do know it occurs in the 2nd to 8th week of gestation. There are 2 options for treatment: limb lengthening surgery, of prosthetic reconstruction (amputation).
I was really upset about the news his doctor gave us today. It is about time for us to decide which treatment route we would like to go. He gave us the pros and cons of each procedure. Limb lengthening would allow him to keep his leg but because the bone he is missing in essential in forming the ankle joint, his ankle would have to be fused together, making it stiff and unable to move. He could also have knee joint problems. With a stiff ankle and bad leg, it would be very hard for him to play any sports. This procedure will require many surgeries, and he will have to wear a large metal brace for 10 months after each procedure. It is a lot for a child to have to go through. Going the other rout, the doctors would perform an amputation below ankle, allowing him to keep his heel so he could walk even if he wasn't wearing a prosthetic leg. Then they would fit him for a prosthetic and we would be on our merry way. This procedure needs to be done before he is 3, so he can best adjust to life with a prosthetic leg. The doctor told me prosthesis are very advanced. They don't let people with prosthetic legs run with the other competitors in the Olympics because the prosthetics allow them to run faster. At first I said "absolutely not". How could I ever decide to let doctors cut off my sons foot?? I do see advantages to the amputation, but I don't know how I could ever come to that decision. I would prefer to lengthen and reconstruct his leg if at all possible. In November we are flying to Shriners Hospital in Salt Lake City (they prefer the lengthening treatment) to get a second opinion. I want what is best for my son. This is going to be one of the hardest decisions I will ever have to make.