Complex sentence: It took four days in hospital for Rolf Wütherich to regain consciousness, and he remained in treatment in the United States for many months because of a skull fracture, pelvic fracture, and upper and lower leg fractures.
Split into simpler sentences: It took four days in hospital for Rolf Wütherich to regain his consciousness. He remained in treatment in the USA for many months because of a skull fracture, pelvic fracture, and upper and lower leg fractures.