Is 35 too soon for a knee replacement!

My right knee is still doing a great impression of a 90 year old so no running again last night, just really hope that all will be well for the Sunday run. It is not a continuous pain however just a sharp little niggle when walking down the stairs but I really don't want to aggravate it.

I'm hoping it's just my trainers, they normally have a life span of around 500 miles which I have now done so probably need a lovely new orthotic too. On the plus side after tomorrow when I'm limping down the stairs at home I'll finally be walking on carpet, only taken us just over 2 years! Actually thinking about it, there goes my lie in this weekend as the carpet man will be round early tomorrow morning and then up for running on Sunday. 2 weeks to Chrimbo, bring it on!!