Can a person with a tibia problem become an air traffic controller?
In the US, an air traffic controller is required to have Class-II medical. However, it is mentioned here that:


  The applicant must have no deformity of spine or limbs of sufficient
  degree to interfere with the requirements of the position of
  employment being sought. Certain limitations of range of motion may be
  acceptable for certain specific options or positions, in which case
  acceptance for employment will be noted specifically for that position
  or option only.


Other than the regulatory standpoint, reaching the top air traffic tower might be hard. There may not be elevators reaching all the way to the top. To save space, many use ladders, not even a staircase.

However, working as air traffic controllers does not always mean in the tower. Many radar rooms are ADA complaint and are wheel chair accessible.