Although we already knew that linebacker Jerod Mayo would be out for the year with a knee injury, we did not know the extend of the injury other than that is was "bad."
We now know how bad. According to Tom Curran of CSNNE, Patriots linebacker Jerod Mayo underwent surgery for a torn patellar tendon today. If the term "patellar tendon" does not mean a whole lot to you (like me), just know that it is the thing that connects the knee cap / quadriceps muscle to the shin.
It is the same injury suffered by Giants wide receiver Victor Cruz in week six. It is certainly within the realm of possibility that Mayo returns next year, but there is more risk to the surgery than ACL repair as you are actually re-connecting a tendon and the doctors need to have precision in recreating the right tension.
Mayo undoubtedly received the best treatment available, and the hope is that there will be no long term weakness to the knee.
Stevan Ridley has yet to undergo surgery, as he must first wait for the MCL portion of his injury to heal.