hi sarit,
the sole reason of a TKR depends on the
walking distance. If you have pain on rest, or as soon as you start walking, or there is too much of bending of your knees, then you should not waste any time and get the replacement done.
However if you have a good walking distance (say more than 2-3 kms), then you will benefit from Synvics injections or a steroid injection also.
So you tell me, wht's your walking distance?