Yes and no. When you first break a bone, the area surrounding the break forms a callus that hardens and remodels itself into new bone, repairing the fracture. This temporarily makes the fracture site stronger than the surrounding area of the bone, but becomes of equal strength after the healing process has occurred.

This saying is possibly attributed to Wolff's Law, which states that a specifies bone in an organism will adapt to the strength which it is placed under. If the loading on a bone is increased, then the bone will remodel itself to resist the application of a heavier pressure.

So, in other words, no. After the healing process is complete (and successful), the bone is of equal strength to the surrounding area of the fractured site.