Rainbow Kids is another organization that advocates for orphans! Unlike Reece's Rainbow they advocate for kids who are typical but they also have a special needs section! They have several kids listed with Arthrogryposis & other related congenital orthopedic special needs (like clubfoot)
In order to view these kids profiles you'll have to create an account but its very easy to do so.
To create an account click here
Most of theses kids profiles have limited information & few view have pictures attached but they have the contact information of the agency they're listed with
Once you've created an account click here to view the profiles of kids with Arthrogryposis