Urethral Trauma
Suspected urethral injury (blood at the meatus, pelvic fracture, or straddle mechanism) means do NOT blindly catheterise — perform a retrograde urethrogram first, divert with a suprapubic catheter, and reconstruct later.
The big picture
Urethral injuries are split anatomically. Posterior urethral injuries accompany pelvic fractures (shearing at the membranous urethra). Anterior urethral injuries are usually straddle injuries crushing the bulbar urethra against the pubis. The cardinal signs are blood at the urethral meatus, inability to void, and a high-riding/boggy prostate on examination.
Blood at the meatus / suspected urethral injury → RUG before any catheter; if disrupted, suprapubic catheter now and reconstruct later.
Red flags
Do NOT catheterise blindly — perform a retrograde urethrogram first.
Suspect posterior urethral injury; image and divert with a suprapubic catheter.
Sign of posterior urethral disruption — RUG before instrumentation.
Mechanism pathway
Tap any step to see why it happens.
The male urethra — four segments
The male urethra — four segments
From bladder to meatus: prostatic → membranous (where the external sphincter sits) → bulbar → penile (spongy). Knowing the segments explains where strictures, injuries and instrumentation problems occur.
Diagnostic algorithm
Each step answers one question. Tap to expand.
Treatment ladder
Avoid converting a partial injury to a complete one: image first, divert urine safely, and reconstruct the resulting stricture electively.
Complications
- Urethral stricture
- Incontinence and erectile dysfunction (posterior injuries)
- Pelvic haematoma/infection
- Worsened injury from blind catheterisation
- Stricture/erectile dysfunction after reconstruction
- RUG before catheter; suprapubic diversion; specialist reconstruction
- Urethroplasty for stricture; sphincter for incontinence
If treatment fails
If the patient develops obstruction after recovery, ask: is this the expected post-traumatic stricture, and what length/location is it?
Memory hooks
Blood at the meatus = RUG, not catheter.
Posterior = pelvic fracture; anterior = straddle.
Divert with a suprapubic catheter.
Reconstruct late (urethroplasty).
Expect a stricture.
Board traps
Blood at the meatus → the answer is RUG, never blind catheterisation.
Choosing immediate open repair for a posterior disruption instead of suprapubic diversion + delayed urethroplasty.
Forgetting to exclude associated bladder injury.
Clinical cases
A man involved in a pelvic-crush injury has blood at the urethral meatus and cannot pass urine. A junior colleague is about to insert a urethral catheter.
What should be done instead, and why?