Risk factors and mechanism of urethral injury in pelvic fractures

Objective To determine the risk factors and mechanism of urethral injury associated with pelvic fractures. Patients and methods A total of 203 consecutive male patients with pelvic fracture were studied prospectively, including a clinical examination, radiographic examination of the pelvis, excretory urography and retrograde urethrography, Results Thirty-nine (19%) patients had urethral injury, five (2.5%) had bladder injury and 12 (6%) had combined urethral and bladder injuries. Urethral injury was by stretching of the intact membranous urethra in 13 patients (25.5%), partial rupture in 13 (25.5%) and complete rupture in 25 (49%). Injury involved the prostatic urethra and bladder neck in three children. Urethral injury was consistently associated with pubic arch fractures. Involvement of the posterior pelvic arch, with fractures of the anterior arch, considerably increased the risk of urethral injury, Also, the risk was greater with an increase in the number of broken rami, Conclusion The highest risk of urethral injury was found in cases with straddle fracture when combined with diastasis of the sacroiliac joint (24 times more than the rest of pelvic fractures); this was followed by straddle fracture alone (3.85 times) and Malgaigne's fracture (3.4 times). Stretching of the membranous urethra usually precedes its rupture, which classically occurs at the bulbomembranous junction.