Urethral injuries are commonly divided by anatomic location and mechanism. Anatomically, the male urethra is divided into the posterior urethra (prostatic and membranous portions) and the anterior urethra (bulbar and pendulous portions); both are susceptible to penetrating and, more commonly, blunt trauma. Female urethras, on the other hand, are both shorter and more mobile than their male counterparts, making them less susceptible to trauma. Female urethral injuries are typically seen in the setting of pelvic fractures and occur in less than 6 percent of these fractures.1
Common causes of injuries
In contrast, male posterior injuries almost always are associated with pelvic fractures with an incidence of more than 10 percent.2,3 Motor vehicle crashes and falls are the most common causes of pelvic fractures leading to urethral disruptions.3 Although the exact mechanism of injury is not fully elucidated, postmortem studies suggest that shearing forces avulse the membranous urethra (fixed to the pelvis by the urogenital diaphragm) from the bulbous urethra.4
Given its position, the anterior urethra is uniquely susceptible to straddle-type injuries, in which the anterior urethra is crushed between the pubic bone and some other object. Common causes of straddle injuries include motor vehicle collision, bicycle crashes, or a direct kick to the perineum. Unlike posterior urethral injuries, anterior urethral injuries are rarely associated with major concomitant organ trauma and thus may go unrecognized.1,3
Unless associated with major hemorrhage, urethral injuries are rarely life-threatening. However, sequelae including stricture may lead to significant long-term morbidity.
To examine the occurrence of urethral injuries in the National Trauma Data Bank® (NTDB®) research admission year 2015, medical records were searched using the International Classification of Diseases, 10th Revision Clinical Modification codes. Specifically searched were records that contained a code of S37.3 (injury of urethra), S37.30 (unspecified injury of urethra), S37.32 (contusion of urethra), S37.33 (laceration of urethra), or S37.39 (other injury of urethra). A total of 929 records were found, of which 893 records listed a primary type of trauma with 83 percent resulting in blunt trauma. A total of 836 records contained a discharge status, including 456 patients discharged to home, 232 to acute care/rehab, and 106 sent to skilled nursing facilities; 42 died (see Figure 1). Of these patients, 92 percent were men, on average 39.3 years of age, had an average hospital length of stay of 12.3 days, an intensive care unit length of stay of 8.7 days, an average injury severity score of 19.4, and were on the ventilator for an average of 8.9 days. Of those tested for alcohol, more than one-quarter (143 of 519) tested positive.
Figure 1. Hospital discharge status
Nonetheless, urethral injuries are relatively uncommon and were only found in one-tenth of 1 percent of records in this dataset. Pelvic fractures and hematuria can be clues to posterior urethral disruptions, whereas anterior urethral disruptions are typically associated with significant soft tissue bruising.4 To stay out of trouble, it is important to keep a high index of suspicion for urethral trauma, especially when the mechanism of injury involves blunt force to the pelvis.
Throughout the year, we will be highlighting NTDB data through brief reports in the Bulletin. The NTDB Annual Report 2016 is available on the ACS website as a PDF file. In addition, information about how to obtain NTDB data for more detailed study is available on our website. To submit your trauma center’s data, contact Melanie L. Neal, Manager, NTDB, at email@example.com.
Statistical support for this article was provided by Ryan Murphy, Data Analyst, NTDB.
- Chapple C, Barbagli G, Jordan G, et al. Consensus statement on urethral trauma. BJU Int. 2004;93(9):1195-1202.
- Morey AF, Brandes S, Dugi DD, et al. Urotrauma: AUA guideline. J Urol. 2014;192(2):327-335.
- Rosenstein DI, Alsikafi NF. Diagnosis and classification of urethral injuries. Urol Clin North Am. 2006;33(1):73-85.
- Mouraviev VB, Santucci RA. Cadaveric anatomy of pelvic fracture urethral distraction injury: Most injuries are distal to the external urinary sphincter. J Urol. 2005;173(3):869-872.