Broke my femur neck on a mountain bike. Surgery, plates and screws. Surgeon said no weight on the broken bone for 8 weeks and no walking on it for 12. And then we'll see he said.
In 4 weeks I was on a trainer (fork fixed to the trainer). Started easy with 30min sessions and then increased time and force applied to the pedals.
After 2 weeks of "riding", started putting weight on the bone with short walks around the house.
8 weeks after the surgery rocked up to a road race, still on crutches because walking was still a bit uncomfy but being on the bike was fine. Raced to a 3rd place (Masters A) with hard breakaways and all.
12 weeks after the surgery go to see the surgeon to check if I can start walking (already walking by this stage as normal). He X-rays me and says your bone is fully healed. Strange but good he said.
I told him the story. Still don't know if he believed me.