We’ll just have to wait and see what the investigation turns up.
There never was a credible source about the so-called surgery. I did a google at the time that this was posted at FR yesterday and it was nothing but rumors bouncing around inside of the ultra-right echo chamber:
http://www.freerepublic.com/focus/news/3284149/posts?page=178#178
There’s now a bazillion sites debunking it:
https://www.google.com/search?q=surgery&ie=utf-8&oe=utf-8#tbm=nws&q=surgery+freddie+gray