With medical science so good nowadays- Almost any Injury can be overcome. Saul Raisin had to give up racing after brain damage in a crash. He got through it-got himself fit enough to get back racing- only to be told that any further accidents that involved a head injury- Might kill him or turn him into a cabbage for the rest of his life. No team is prepared to take the chance of that injury occuring so he has had to retire. He still rides but no longer competitively.