You are only partially correct. I've seen more than a few times in this thread the misunderstanding that the provider (the Doctor) and their fees that are the main culprit when it comes to the high cost of medicine. Unfortunately, the people that are being screwed in today's health care system are the patient, and (wait for it...) the doctor. The federal government, and its partner the insurance industry are the problem. The Fed and its Medicare reporting mandates (which are adopted by the insurance industry) have driven the cost of practicing medicine to unacceptable levels for many doctors. I'm guessing that many of you have no idea what an ICD code is, or the complexity involved with proper use of the codes required for reimbursement. Mistakes in coding literally can result in thousands in lost fees. Further, the insurance industry specializes in looking for these mistakes and bouncing claims requiring many cycles of re-submission. Who does the resubmission? The expensive team of administrators that doctors must now employ to ensure that they get repaid.
I noticed that you wanted to use total knee replacement as an example. Total knees are now part of a bundled payment model - essentially medicare pays 25k for the procedure. Out of this 25k the hospital gets its cut, doctors (anesthesiologist, ortho, etc.) get a cut, cost of the device, physical therapy, home care, etc. If there is a problem and a patient is readmitted then there is a medicare penalty to pay. Bundled payments are a big reason why fewer hospitals are not for profit, but are instead owned by for-profit entities. Honestly, they don't give a damn that there are too few nurses to care for patients, etc. - it is all about the bottom line.
Doctors are retiring early in record numbers because the art, vocation, and practice of medicine that many signed up for is no longer the reality. Have you ever wondered why your annual physical used to be a one hour session where the doctor took time to ask about your family, life, etc. Now it is 30 - 45 minutes and the conversation is driven by a questionnaire provided by the insurer - don't fill out the questionnaire, you don't get paid.
My doctor just switched to a concierge model - no insurance, and I signed-up. I am fortunate that I can afford this option, and honestly it is sad that government overreach, and insurer greed have lead us to this point.
Yes, I am generally conservative, but healthcare will not be fixed until both sides agree to de-politicize the problem, and focus on a new solution. The ACA while having a few good points is overall a disaster, however the Republican plan doesn't seem to be a great solution either. The real fix would be to start from scratch, take the time needed (2 years, 3 years, etc.) to craft a plan that benefits the patient, encourages providers to treat/heal, and allow the supporting business (Pharma, equip mfg, etc.) to profit from their research and production. A pipe dream, I know...