What is the mortality rate of a 90+ year old woman undergoing a hip replacement?

THA mortality: Depends. Without surgery, likely death rate within 6 months is greater than 50%. With surgery, about 11% at 6 months. This obviously has to be qualified by general health, pre-existing conditions, diabetes, cardiac health, pulmonary health, obesity or malnutrition status, infection, clots, mental status, and motivation of the patient.