A: The correct code is 321020.4. A common coding error is to assign the code 321016.4 which is the first code referring to thrombosis seen in the dictionary. That code refers to thrombosis resulting from a laceration to the artery so we must use the code below which states “thrombosis (occlusion) secondary to truama”. In AIS 2005 this is further clarified to read “thrombosis (occlusion) secondary to trauma from any lesion but laceration”.