Traumatic pubic diastasis with rupture of the membranous urethra

Case contributed by Dr Wayland Wang


Motorbike accident.

Patient Data

Age: 25 years
Gender: Male

There is a moderately displaced, comminuted fracture of the right iliac wing. A transverse line of the fracture extends to the inferior margin of the right sacroiliac joint with gas locules in the SIJ. There is gross diastasis of the pubic symphysis with overlap of the pubic bodies and tiny surrounding osseous fragments. A small extraperitoneal hematoma is seen on the left abutting the anterior aspect of the bladder and in the left retropubic region. Small hematoma is also seen in the right lower rectus sheath and underlying soft tissues. No contrast extravasation is demonstrated.

The bladder is thin walled and not collapsed. On the delayed imaging contrast is seen flowing from ureters to the bladder. Dependent layering of material in the bladder suggests small volume clot. There is stranding around the membranous urethra, suggesting traumatic injury.

Fractures of the left L1-L4 transverse processes. No other injuries demonstrated.


Pelvic fractures involving the right iliac wing and pubic symphysis diastasis with small extraperitoneal hematoma and no contrast extravasation. No evidence of bladder injury on this study, however there is suspected injury to the membranous urethra.

Ccontrast medium administered into the urethra outlines a normal caliber penile urethra. Irregularity and extravasation of contrast is present at the level of the membranous urethra with only a small volume of contrast passing beyond into the prostatic urethra. Contrast in the bladder likely relates to previous intravenous contrast.

Conclusion: Findings are in keeping with traumatic injury of the membranous urethra.

Case Discussion

Traumatic urethral injury is an important potential complication of pelvic fractures, especially those involving the pubic symphysis or pubic rami. It should be considered whenever there are pelvic injuries, especially when injuries involve the midline or paramedian structures.

While CT is the cornerstone of trauma imaging, it is inadequate in assessing the urethra. This is best done radiographically, after administration of contrast media via the urethra. A single oblique projection (to capture the whole length of the urethra) is often enough to demonstrate any potential injuries.

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Case information

rID: 51035
Published: 16th Oct 2020
Last edited: 16th Oct 2020
System: Urogenital
Inclusion in quiz mode: Included