Fracture locations influence the likelihood of rectal and lower urinary tract injuries in patients sustaining pelvic fractures.

Background: Rectal and lower urinary tract injuries in pelvic fractures can lead to significant complications. We sought to determine whether fracture locations could serve as markers for injury.

Methods: In our retrospective review of patients with blunt pelvic fractures, the association of fracture locations with injury to the rectum, bladder, and urethra was explored with Fisher's exact test and subsequently analyzed with multiple logistic regression.

Results: Of the 362 patients reviewed, 8 had rectal injury and 24 had lower urinary tract injury. The following locations were found to be significant. Rectum: symphysis pubis (relative risk [RR] = 3.3, p < 0.001) and sacroiliac (SI) joint (RR = 2.1, p = 0.014). Bladder: symphysis pubis (RR = 2.1, p < 0.001), SI joint (RR = 2.0, p < 0.001), and sacrum (RR = 1.6, p = 0.002). Urethra: symphysis pubis (RR = 2.9, p = 0.003), SI joint (RR = 1.8, p = 0.04), and inferior ramus (RR = 4.6, p = 0.008). After multivariate analysis, the primary and independent predictors for each of the injuries were as follows: rectal injury, widened symphysis; bladder injury, widened symphysis and SI joint; and urethral injury, widened symphysis and fracture of the inferior pubic ramus. Although these associations were significant, the overall prevalence of associated rectal and urologic injuries was low. Consequently, the predictive values of these radiologic findings were also low, ranging from 5% to 9% for urethral and rectal injuries to 20% for bladder injuries.

Conclusion: Certain fracture locations are associated with increased risk for rectal, bladder, or urethral injury. Fractures involving these locations should prompt further work-up for assessment.