For those that grind spare rib trimmings

I know I have seen people mention that they grind up the spare rib trimmings to use in sausage, chili and such. My question is, do you remove the cartilage as best you can or do you just grind it in? If you remove it, are there any good tips on doing this effeciently? If you grind it it, I assume you want to grind as fine as possible but I still hate having that grit in there. Also, do you find there is enough fat in the trimmings for decent sausage? I was also thinking about mixing with a higher fat content sausage from the store. Also, any other prep or cooking suggestions are greatly appreciated.