In Canada or in Quebec, in the civilian world, when a person breaks a leg or an arm, as a rule, the employer does not challenge that obvious fact. However, a certain consolidation period applies, after which an administrative decision may be made to let that person go or to not take him back on.
I would imagine that this could also be done in the Canadian Forces. If a person breaks a leg in several places and cannot return to active duty, can he be discharged from the forces?