Most people our age Steve have knee issues, I know how bad yours was at LakeZ.
Actually for those who know him my son Lee has a big knee Op on Monday. ATL (Cruciate Ligament) reconstruction after a MotoX mishap a few months (April) ago.
Good luck mate, I'm sure you'll come out of it much happier. My dad goes for his hip operation next week, 6 weeks of recovery after a week in hospital!
Best of British Steve - I know what a difference having both my hips replaced made to me, so it is worth the pain in the short term when you can get around easily again
If ever you need an honest opinion on knees, just remember the wife is a knee & hip surgeon, so I'm sure she'll be happy to talk you through anything you want!
Had you been on the South coast, it would have likely been her doing your op! (And same applies to the others having knee/hip ops!!!)