Complex sentence: Manning's last years were also made difficult by physical deterioration; arthritis increasingly affected her, leading hip replacements in 1976 and in 1979, and she suffered ongoing poor health related to amoebic dysentery caught in the Middle East.
Split into simpler sentences: Manning's last years were also made difficult by physical deterioration; arthritis increasingly affected her, and she had hip replacements in 1976 and in 1979. She also suffered ongoing poor health related to amoebic dysentery caught in the Middle East.