Do they now have wriste replacement s like they do for knees?

Don't think so: The wrist is a much more complex joint than the knees, but replacements can be performed at specialized centers.

Dr Fowler agreed

Yes we have: Wrist replacement surgery may help retain or recover wrist movements. It may also improve the ability to perform daily living activities, especially if there is arthritis in the elbow and shoulder. During any total joint replacement, the worn-out ends of the bones are removed and replaced by an artificial joint (prosthesis). From aaos.