The nature of urethral injury in cases of pelvic fracture urethral trauma

PURPOSE: We examine the urethral injury associated with pelvic fracture that is said to be due to a shearing force through the membranous urethra which inevitably destroys the urethral sphincter mechanism. MATERIALS AND METHODS: A total of 20 asymptomatic cases were prospectively studied, including symptomatically, radiologically, endoscopically and urodynamically, 1 to 4 years after an apparently successful anastomotic repair of a pelvic fracture urethral distraction defect. RESULTS: There was evidence of urethral sphincter function, including urodynamically in 11 (55%), endoscopically in 13 (65%) and functionally in 17 (85%) patients. CONCLUSIONS: These findings, coupled with surgical observation, suggest that the urethral injury associated with pelvic fracture is avulsion of the membranous urethra from the bulbar urethra rather than a shearing through the membranous urethra, and that some degree of urethral sphincter function is preserved in a significant percentage of patients.