I'm 65 and had a TKR (right) two years ago. I've ridden with SPD mountain bike cleats for the past 20 years and after my knee replacement I have continued with cleats. I haven't encountered any pain but I've also had my cleats positioned on my shoes by a professional bike fitter. I think getting the cleats in the correct position and having the rest of your bike fit correctly goes a long way toward alleviating any pain. If it hurts the fit might not be quite right.