Blunt urethral trauma: a unified, anatomical mechanical classification.

PURPOSE: We propose a simple, anatomically based classification of blunt urethral injury as a replacement for currently used classifications, which are not comprehensive, anatomically inconsistent or based on a mixed anatomical/mechanistic formula. The latter are difficult to learn and use, and have not been universally adopted.

MATERIALS AND METHODS: We reviewed most of the currently used general uroradiological, emergency radiological and urological textbooks to define the classification of urethral injuries that is most widely accepted. Most authors use the Colapinto and McCallum classification, modifications thereof or the older surgical classification of urethral injuries, which simply divides such injuries anatomically into anterior and posterior. However, there is little consensus about the best classification and none includes all of the blunt injuries of the urethra. To correct these difficulties we devised a comprehensive and anatomically consistent classification.

RESULTS: The proposed classification categorizes blunt urethral trauma as I-posterior urethra intact but stretched (Colapinto and McCallum type I), II-partial or complete pure posterior injury with tear of membranous urethra above the urogenital diaphragm (Colapinto and McCallum type II), III-partial or complete combined anterior/posterior urethral injury with disruption of the urogenital diaphragm (Colapinto and McCallum type III), IV-bladder neck injury with extension into the urethra, IVA-injury of the base of the bladder with periurethral extravasation simulating a true type IV urethral injury and V-partial or complete pure anterior urethral injury.

CONCLUSIONS: The proposed classification is anatomically valid and includes all of the common types of blunt urethral injuries. Universal adoption of this system should permit comparison of various management/treatment modalities at various institutions.