I had mine done on the NHS,I only had to wait 5 months for it and it was over winter so I wasn't too bothered plus after 6 weeks of rest and anti-inflamitorys I did some training anyway,just long steady winter miles.Ensure you keep your knees well wrapped up though,the surgeon warned me that with the mileage I do and for how long I've done it for there was a good chance the knee would be shot,but after the op he told me it was in very good condition,in winter I always keep my knees covered and always use embrocation in early season events,the knee has no protection,ie fat,to keep it warm yet some nutters still only wear shorts in winter,apart from when racing it has to be over 20 degrees for me to be in shorts!