In two weeks, I'll be 42. By now, the evidence from 3 knee surgeries is well hidden. I can fake my way through a lot of medical exams. But I'm still 3 years over the limit.
They said no back in 1980 when they looked the 1st time. I screwed up by not accepting the offer of an appointment to the AF Academy (one of Dad's friends was a senator) because they told me I still wouldn't get to fly because they could see the scars, and I was 6'2" and 225#, they didn't want pilots that big, or so I was told. They could still see the scars in 1990-91. The examining doctor said "Son, we make our own problems with injuries here, we don't need yours."
I could probably pass the physical (I passed an FAA physical AND other physicals recently to renew my competition license for racing) if they didn't look too close at the knee. But I'd need 90 days to get into decent shape.