Urethral injuries may be partial or complete. In males they are classified as posterior (at or above the membranous urethra) or anterior (penile/bulbar) — a distinction that determines management: posterior injuries are drained and repaired late, whereas penetrating anterior injuries are repaired early.
Background and Pathogenesis
- Posterior injuries are almost exclusively associated with pelvic fractures (urethral injury occurs in ~10% of males and up to 6% of females with pelvic fractures). The bulbomembranous junction is most vulnerable because the posterior urethra is densely anchored to the pubis by the urogenital diaphragm and puboprostatic ligaments.
- Anterior injuries are blunt (straddle injury, crushing the urethra against the pubis) or penetrating, most commonly involving the bulbar urethra (its fixed position beneath the pubis).
Diagnosis and Evaluation
- Indicators — blood at the urethral meatus is the most common finding, plus inability to urinate, perineal/genital ecchymosis, a high-riding prostate (males), and labial edema/vaginal blood (females). If Buck's fascia is disrupted, blood and urine track into the scrotum and up the abdominal wall (deep to Scarpa's, limited posteriorly by Colles' fascia) — the classic butterfly pattern.
- Imaging — retrograde urethrogram (RUG) is performed immediately when injury is suspected; avoid blind catheter passage before the RUG. Position the patient obliquely, place a 12-Fr Foley or catheter-tipped syringe in the fossa navicularis with the penis on traction, and inject 20–25 mL of undiluted contrast. In female patients, urethroscopy is suggested instead of RUG (the urethra is short).
Management
The immediate goal is securing bladder drainage. With a partial disruption (contrast passes proximally on RUG), an experienced clinician may make a single gentle catheter attempt.
Male — Posterior
Pelvic fracture urethral injury (PFUI): immediate suprapubic tube with delayed repair. The suprapubic tube is the gold standard (it can be placed even with ORIF, without raising hardware-infection risk). Primary realignment (advancing a catheter across the rupture) may yield less severe strictures than an SPT alone but over a longer course — the ED is an inappropriate setting for it, and prolonged endoscopic attempts should be avoided. Immediate sutured repair causes unacceptable rates of ED and incontinence. Most patients develop an obliterative rupture defect filled with scar (not a stricture), amenable to open perineal anastomotic posterior urethroplasty — performed at ~3 months once ambulatory and stable (limit lithotomy time to ≤5 hours), and preferred by the AUA over endoscopic treatment. After urethroplasty, 5–15% develop recurrent stenosis and incontinence rates are low (<4%); follow for at least 1 year.
Male — Anterior
- Contusions/incomplete injuries — urethral catheter diversion alone.
- Straddle injury — suprapubic tube (or primary realignment in milder cases) with delayed repair; immediate operative intervention is contraindicated (indistinct injury borders), and obliterated bulbar segments are later treated by delayed anastomotic urethroplasty.
- Penetrating trauma — prompt spatulated primary repair gives superior outcomes (unlike PFUI/straddle, where delayed repair is preferred), unless the patient is unstable or there is extensive tissue loss.
Female
Pelvic-fracture urethral disruption is treated by immediate primary repair or realignment over a catheter, to avoid urethrovaginal fistula or obliteration — delayed reconstruction is problematic because the female urethra (~4 cm) is too short to mobilise once embedded in scar.
Self-Test
1. What clinical findings suggest urethral trauma? Blood at the meatus, inability to urinate, perineal/genital ecchymosis, and a high-riding prostate.
2. What is the next step in a patient with suspected urethral injury, and how is it performed? A retrograde urethrogram — position the patient obliquely, place a 12-Fr catheter or syringe in the fossa navicularis, and inject ~20 mL of undiluted water-soluble contrast.
3. What is the management of a posterior urethral disruption with a pelvic fracture? Suprapubic tube with delayed repair (the earliest reconstruction is at ~3 months).
4. What is the management of an anterior urethral disruption from penetrating trauma versus a straddle injury? Penetrating — prompt surgical (spatulated primary) repair; straddle — prompt urinary drainage with delayed repair.
5. Which part of the urethra is most likely injured in a straddle injury? The bulbar urethra.
6. What are the potential complications of urethral injury? Urethral stricture, erectile dysfunction, and incontinence.