Not an elbow injury, rather it is a torn triceps... Smith had a bone spur attached to his triceps tendon that became detached in his left elbow, Matt Maiocco of Comcast SportsNet Bay Area reported.
"Smith was injured in a Week 15 win over the New England Patriots and hasn't practiced since. The Bee reported Smith is likely to undergo offseason surgery, but the 49ers hope he can play through the pain during the team's voyage through the NFC playoffs."
That would be a tough injury to play through. It reminds me of the loss of Red Bryant last year when our defense crumbled after he went down... the 49ers better learn to adjust or they will be one and done.