In reply to Bob Kemp:
Hi Bob
As an orthopaedic surgeon (who does a fair number of knee replacements), I would agree completely with the advice about rehab after surgery given above. The rehabilitation is at least half of the issue.
I am a peripheral part of a research project looking at return to mountain activities of patients after hip and knee replacements. As you say there is not a lot of evidence about what is safe / advisable; unfortunately surgeons or physios then tend to default to advising against it.
I have had several patients who have returned to climbing after joint replacements. There are obviously some risks with this, but particularly after knee replacement they are probably small in the short term. The long term worry is about loading in marked knee flexion leading to loosening of the implant which would require revision. This is mainly a theoretical risk, as there doesnt seem to be any evidence about it. Which is another way of saying that if you decide to go ahead and climb you will have to deal with the consequences....which is similar to any decision to go climbing! There is also a small risk of fracture adjacent to the implant due to falls, which can lead to technically difficult problems in fixing the fracture. I personally have never seen a peri prosthetic fracture relating to climbing.
Essentially, at present there is a philosophical question about lower limb joint replacements that we cannot answer empirically .. ie should people be encouraged to return to full activities after joint replacement, or should they reduce their activities to "protect" their joint (even though the evidence that it does protect the joint is minimal, although there is some evidence that running damages joint replacements). In view of the lack of evidence, my view is that people with joint replacements can reasonably return to mountain sports providing that they think that the benefits of this are considerable, providing that they accept that some consequences cannot be foreseen.
I hope this helps
Regards
Glynne