It wasn't previously clear what was wrong with Vitor's knee. Now we know, and it appears that it has been fixed. Via team press release.
The Boston Celtics announced today that center Vitor Faverani had successful left knee arthroscopy to repair a torn lateral meniscus at the New England Baptist Hospital. The procedure was performed by Celtics team physician Dr. Brian McKeon and was assisted by Jason Rand, PAC. Faverani will not return this season.
Another one bites the dust. This shouldn't be all that surprising though.