The average hospital charge for a total knee replacement (TKR) in the United States is $49,500. A partial knee replacement (PKR) typically costs about 10 to 20 percent less than a TKR. The main reason is that the operation requires a shorter hospital stay.For example: an average of 2.3 days, compared to 3.4 days.Keep in mind that hospital charges don’t reflect the amount you pay out of pocket.he cost of a knee replacement can vary substantially, even within the same geographical area. The final hospital charge depends on many factors, including: 1  number of days spent in the hospital: This will vary depending on the type of knee replacement you have (total, partial, or bilateral).