Surgery had developed incredibly quickly since World War II. The main advances have been:

Transplants - the first successful kidney transplant was in 1954 and the first heart transplant was performed in South Africa in 1967 by Christian Barnard and in the UK in 1968; the drug cyclosporine was developed in 1970 to stop the body rejecting new organs. Hip replacements have been common since the 1970s;
Keyhole Surgery - enables much quicker recovery times as less damage is done to the body;
Microsurgery - the ability to join tiny blood vessels and nerves enables amazing new procedures such as hand transplants and neural surgery.
Prosthetics - e.g. bionic eyes.

The key factors that have enabled this have been technology, science and wealth.

GCSE Health and the People AQA

Surgery since 1945