As a Physician Assistant working on a total joint service I get this question all the time. It is a very loaded question, with a very nebulous answer.
Every major surgery takes roughly a FULL YEAR to recover. Not what everyone wants to hear. This does not mean that you feel miserable for a year. “Misery” after surgery usually encompasses the first few weeks and a few rough days of physical therapy along the road. Getting back to “normal” depends more on your baseline fitness and expectations. The stronger you are prior to a surgery, the faster you will return back to “normal function”. I see some “fit” patients return to most activities in less than 2 months after a partial / total knee replacement or total hip. This is not the norm. Most of our patients are significantly limited pre-operatively and are unable to maintain good strength and fitness. The majority of patients require extended physical therapy and home exercises to get to their goals over time.
My overriding point is that all of our patients start from a different place, fitness wise. It is important to self-assess and be realistic about where you are starting from. Stronger / fitter patients will progress quicker, while your average or below average patient will take more time.
I encourage all patients to stay strong and stay skinny. These are by far the most difficult things I suggest, but they will bring you back to NORMAL faster.