I like Turtles.
Golden Rule #1 If you choose to ride, you assume any and all risks.
Golden Rule #2 Any protective gear you choose to wear is a personal choice.
Like many of us, we have seen many injuries over the years or have been injured. This is a dangerous sport. But, working the tracks over the years has made me eye witness to many injuries. Many femur, knee, shoulder, tib/fib, ankle, wrists and so on.
I am sure any broken bone or torn soft tissue is painful...some a higher degree than others and also depends on the individual rider. A bone is usually much easier to fix than soft tissue.
My personal choice is to wear knee braces, more than anything they stabilize the knee after all the pounding they take. Every femur brake that I have known of personally have not resulted in lacerating the femoral artery...but the femoral artery is always the MAJOR concern. A femur break usually doesn't cause any long term problems unless its the head of the bone that connects to hip...a JOINT.
I have witnessed knee injuries (a JOINT) cause long term pain and instability. Total knee raplacements are not usually done until old age. Any injury that is sustained by the rider has the best medical technology available now a days then we have ever seen.
Just like neck braces, you can slice the pie a thousand different ways...eithe way, you will be always playing the odds.
You best protective gear...being smart by making good decisions in bike prep and when your on the course.
You will crash...it's not a matter of if, but when.
Can't believe this is relevant...I find this saying extremely annoying from the movie The Hunger Games...perhaps because of the woman saying it...but may the odds ever be in your favor.
Again...no matter what, everytime you go ride or race, you are rolling the dice no matter how much protective gear you are or aren't wearing.