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. 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.