Recall my mother pointingy out my knees were 'different'. I suffered
a knee sprain in
1977, used crutches for a month , then took up  jogging in fall 78 for
9 weeks. Took up
some martial arts and was on the go quite a lot over the years (I
didn't drive!). Was
slim as a child, then got heavier in the pubescent years. Lost weight
in late Seventies
but then gained back in Eighties thru Nineties. Just lost weight in
recent months which
was quite a lot in years. Cartilage has worn out in both knees and I
experince a tingling
sensation especially in my right knee and both feet (RLS?) after
walking a distance.
Also have a herniated cervical vertebrae according to a diagnosis in
late March.(This
last may have been attributed to poor posture over time and/or lifing
boxes up and down the
stairs to a storage room in the basement last year) Perhaps the
herniated disc is aggravating
my knee as well. Truly I feel at peace when asleep!