I'm 26 and have PFFD of my right leg. I am going to attempt to make a long story short -- I went to Shriners until I was about 21 where I had all of my surgeries. I had a handful of hip surgeries to build me a ball and socket. I broke some plates, and pins, and screws, but it was eventually successful-ish. Also, I had four lengthenings (three times on my femur, once on the tibia). I don't remember how many centimeters in length I got, but I do remember the doctor telling me "all together that equals about 13 inches".