Complex sentence: In 1955, G. A. Ilizarov determined that if bone fragments are carefully pulled apart, without disturbing their coaxiality, then the bone fragments will grow together across the intervening space.
Split into simpler sentences: In 1955, G. A. Ilizarov determined that bone fragments can be carefully pulled apart, without disturbing their alignment. The bone fragments will then grow together across the intervening space.