THE rising tide of urban violence has made penetrating wounds one of the more frequent surgical emergencies. In recent years, hand guns have replaced knives as the most commonly employed weapon, with a resulting rise in the number, complexity and mortality rates from these injuries. The small caliber and low muzzle velocity that once characterized civilian firearms is less predictable. In addition, an awesome array of wounds resulting from knives, instruments, ice picks, explosion fragments and impalement injuries are being encountered. Once confined largely to the criminal element in society, the modern "victim" may be an innocent bystander, woman, small . . .