Knee replacement for riding?

[javen]

My older female cousin underwent knee surgery due to a vehicular accident and she is recovering with a right knee replacement. She's an equestrian but considering her situation right now, it would be difficult for her to climb up the horse saddle with a bad knee. Anyone with a knee replacement know how to climb with a saddle position with ease?

[BigBackyard]

I am not in this position but wonder-would it be wise for her to ride at all? It seems a big risk, in that it could cause excessive wear to the artificial joint.