I had both my knees replaced last year. The left one in February went without a hitch, with the anaesthetist getting the line in my arm within seconds and I was out to it before I knew it. An hour or so after the op I was able to get out of bed and go to the toilet without much discomfort at all.
The right knee in September a totally different story. A different anaesthetist who seemed to take forever to find a vein to put the line in. Messed around trying with my left hand before eventually being successful with the right arm. Afterwards when I got out of bed the pain was excruciating. I am guessing he didn’t put enough local in the knee, and to this day the little finger on my left hand is numb. I mentioned it to the surgeon at my last post op appointment and he said it would get back to normal eventually. I should have asked him how long was eventually.