On one of my horses the splint just appear one day, horse was never lame on it and the area around splint was never sore, so i just ignored it! Think she was about 7 when it happened...she's 13 now and its completely gone, not even a slight bump can be felt.
Another horse i ride had one come...
My mare was awful to catch for the first 4/5 years of having her!!!...it can be so frustrating at times..especially when your in a rush...i have literally spent whole days sat in the field trying to catch her!!
What worked for me was to tie loops of string (approx 10inch loop) to her...