Will medical titanium alloy be deformed?

Did the fibula touch the board? Generally, as long as the fibula fracture is well aligned, there is no need to hit the board. You mean the tibia.

Titanium alloy plates have good durability and seldom break. General repetitive actions will reduce durability, such as pedaling a bicycle.

Don't pedal your bike if you have nothing to do, so it won't deform.