This is an awfully old thread! Never the less, I'll add my two penn'orth!

I've worked with a lot of hip surgeons over the years and to be honest, this is a relatively recent protocol (recent as in since the last 15-20 years - yes, I'm old!!).

When McKee and Charnley were doing hip replacements back in the 60s and 70s, the thought never crossed their minds! Nor for all the thousands who had hemiarthroplasties as well. And their dislocation rates were no more or less then than they are these days.

I currently continue to have acquaintanceships with many hip surgeons and in a straw poll, less than half of them confessed to imposing these restrictions on their patients. Last September I attended a symposium on THR in Edinburgh and this was a general consensus there also - the majority do not impose them.