Of these modes of fracture, the following require trepanning: the contusion, whether the bone be laid bare or not; and the fissure, whether apparent or not. And if, when an indentation (hedra) by a weapon takes place in a bone it be attended with fracture and contusion, and even if contusion alone, without fracture, be combined with the indentation, it requires trepanning. A bone depressed from position rarely requires trepanning; and those which are most pressed and broken require trepanning the least; neither does an indentation (hedra) without fracture and contusion require trepanning; nor does a notch, provided it is large and wide; for a notch and a hedra are the same.