Board Thread:General Discussion/@comment-65.31.134.55-20130328025957/@comment-6747658-20130330123508

....that's an image taken from the trailer...and that "black scar" is in fact the horn/shrapnel/whatever.

The robotic limb is his prostethic arm, gained after the Hospital incident and most likely takes it's design from Gálvez who had a similar prostethic limb, albeit it was his right arm where as with Big Boss, it's the left.