According to Kevin Seifert on the ESPN NFC Blog, the Lions have released LB Vinny Ciurciu. 

I think with how well Landon Johnson has played, this shouldn't be a huge surprise.  I thought that Ciurciu may have shown enough to be considered dependable depth and a good special teamer, but there are not many spots to go around.  I do believe that Ciurciu was hurt in the Buffalo game as well, which may have contributed to the decision.