The decision on when to walk depends on the recovery status of the fracture. Generally, a tibial fracture requires about 4-6 weeks of rest. Around 4-6 weeks, you can revisit the hospital for an X-ray checkup. If the callus is growing well, and the fracture line is blurred or disappeared, you can start using crutches to walk and perform functional exercises.

However, recovery from a comminuted fracture takes longer, so an X-ray examination is essential before starting to walk. If the examination results show good recovery, then you can start walking. If you walk too early, it may interfere with the fracture healing, and in severe cases, it might even cause the fracture to break again.

Therefore, the time it takes for someone with a comminuted tibial fracture to walk depends on the specific circumstances, and an X-ray examination must be performed before walking.