OTOH wrote:
How much will his marathon time improve?
Having femurs 3" longer should make his stride length longer with faster times if he can keep his cadence the same. If it works, i say go for broke and do the same operation on his lower legs.
Will the iaaf allow osteo-doping as a mental TUE?
You'd think it would be an advantage. The problem is: your hamstrings are suddenly stretched way too much for the longer bones. I guess having a lot of flexibility is a must to even have the surgery done.