I thought I'd just post this for you, news from the UK where the last surgeon has just rejected the "freedom disc", I think you're just doing trials in the USA.
Interestingly enough the UK patient has just been offered this prosthesis which is a lateral approach
Spinal Surgery News - Online
very best wishes to all members
Alastair
founder and admin of the UK board, so I'm sorry I don't get on here much