PassFinals
Renal & Urology

Testicular Torsion

Rotation of the spermatic cord obstructs venous outflow and then arterial inflow, so the testis infarcts within hours unless it is surgically untwisted.

In a nutshell

Testicular torsion is a surgical emergency: salvage falls from 90 to 100 per cent within 6 hours of onset to under 10 per cent beyond 24 hours. Escalate immediately, keep the patient nil by mouth, give morphine 5 mg by slow intravenous injection, and never delay theatre for a scan.

Classic presentation

A 14-year-old boy with sudden severe left testicular pain and vomiting, and a swollen high-riding testis lying transversely with no cremasteric reflex.

Key points

  • Incidence is around 1 in 4000 males under 25 each year, peaking at 12 to 18 years with a second, smaller peak around birth.
  • Intravaginal torsion, inside the tunica vaginalis, is the adolescent type. Extravaginal torsion, testis and coverings together, is the neonatal type.
  • Bell-clapper anatomy means the testis lacks its normal posterior anchoring and hangs freely inside the tunica vaginalis.
  • If an ultrasound is genuinely indicated it should be done within 18 hours of presentation.
  • Ultrasound has a pooled sensitivity of 92 per cent, so scanning alone misses roughly 1 in 12 torsions.

First-line investigation

There is none: the diagnosis is clinical, and scrotal exploration is the only test that reliably confirms or excludes torsion.

Management

Escalate and start the clock

  • Assume torsion in any acute severe testicular pain. Record the hour pain started. Telephone urology or paediatric surgery directly; a surgical decision maker should review within 60 minutes of arrival.3,4,1
  • Nil by mouth immediately. Insert a cannula, send bloods and a group and save. Waiting to fast the patient is only reasonable if pain already exceeds 24 hours.1,3
  • Morphine 5 mg by slow intravenous injection every 4 hours for an adult or ages 12 to 17; 100 micrograms/kg over at least 5 minutes for ages 2 to 11.7

Decide clinically, not radiologically

  • Score TWIST (Testicular Workup for Ischaemia and Suspected Torsion): testicular swelling 2, hard testis 2, high-riding testis 1, nausea or vomiting 1, absent cremasteric reflex 1.3,1
  • TWIST 5 or more with under 48 hours of pain mandates exploration. A score of 0 to 4 does not exclude torsion and does not permit discharge.3,4
  • Ultrasound only for a suspected alternative diagnosis, pain of 48 hours or more, or a newborn. Never transfer for a scan and never let one significantly delay theatre.3,5

Consent and special groups

  • Consent covers orchidectomy, reduced fertility, contralateral injury, haematoma, wound or testicular infection, and aspiration if induction is unfasted. Support the discussion and check it is documented.2
  • Under 2 years, a newborn with suspected antenatal torsion, or an undescended testis: involve the paediatric surgical centre, and scan the newborn to exclude other diagnoses.3,1

Theatre

  • Scrotal exploration within 1 hour of the decision to operate when pain has lasted under 48 hours. Exploration is the diagnostic test as well as the treatment.3,5
  • Untwist the cord and fix a viable testis in a Dartos pouch or with non-absorbable sutures. Wrap an ischaemic testis in warm saline-soaked gauze and reassess.2,8
  • Fix the contralateral testis at the same anaesthetic, saved or not, because bell-clapper anatomy is usually bilateral. Remove a non-viable testis; no prosthesis at this operation.4,2

Counsel and follow up

  • After orchidopexy, arrange follow-up for delayed testicular atrophy; NHS urology review is typically at 6 to 8 weeks. After orchidectomy, arrange patient-initiated follow-up (PIFU) for prosthesis discussion.3,9
  • Advise no vigorous exercise for 4 to 6 weeks and no sexual activity for about 2 weeks. Seek urgent reassessment for recurrent pain, fever or a wound problem.9

Exam traps

  • A normal Doppler ultrasound does not exclude torsion. Partial and intermittent torsion can preserve flow, and the scan is operator-dependent.
  • A present cremasteric reflex does not exclude torsion, and its absence is a late sign rather than a diagnostic one.
  • One in three confirmed torsions scores 0 to 4 on TWIST, so a low score is never a discharge decision.
  • A previous episode that settled on its own is intermittent torsion until proven otherwise, not reassurance.
  • In a child, lower abdominal pain may be the only symptom. Examine the scrotum of every boy with abdominal pain.
  • Prehn's sign, relief on lifting the scrotum, is unreliable in both directions and should not change your decision.
  • Neither a normal nor an abnormal urine dipstick excludes torsion.
  • Exploration beyond 14 hours still saved 46 of 122 UK testes, so late presentation is not a reason to stand down.

Illustrations

Testicular torsion at explorationIntra-operative view of a torted, congested testis during scrotal exploration.Javier.montero.arredondo, Wikimedia Commons · CC-BY-SA-4.0
Time-critical pathway for suspected torsionDiagram of the time-critical pathway: surgical decision maker within 60 minutes of arrival, TWIST scoring, then scrotal exploration within 1 hour of the decision to operate. Ultrasound appears in three narrow situations only.PassFinals · original

Key sources

  1. British Association of Urological Surgeons: Testicular torsion (trainee guidance) (Source for bell-clapper anatomy, intravaginal versus extravaginal torsion, the 12 to 18 year peak, TWIST components and risk bands, salvage rates by time from onset, and the instruction to keep the patient nil by mouth, obtain intravenous access, give analgesia and not delay surgery for imaging.)
  2. BURST and British Association of Urological Surgeons FIX-IT consensus: best practice in the conduct of scrotal exploration for suspected testicular torsion, BJU International 2022 (UK consensus source for the consent list, intra-operative decision making, warm saline-soaked gauze and reassessment, Dartos pouch versus non-absorbable suture fixation, contralateral exploration and fixation, and deferring prosthesis discussion.)
  3. Getting It Right First Time (GIRFT) Children and Young People: Testicular torsion pathway, version 2.1, May 2026 (Current national pathway. Source for surgical decision maker review within 60 minutes of arrival, TWIST 5 or more mandating exploration, TWIST 0 to 4 not excluding torsion, the three indications for ultrasound, the 18-hour scan limit, exploration within 1 hour of the decision to operate, pooled ultrasound sensitivity and specificity, and follow-up arrangements.)
  4. National Confidential Enquiry into Patient Outcome and Death (NCEPOD): Twist and Shout, a review of the pathway and quality of care provided to children and young people aged 2 to 24 years who presented to hospital with testicular torsion, 2024 (UK national audit. Source for 97 per cent salvage when surgery occurs within six hours of onset, orchidopexy rates of 94.0 per cent under 6 hours, 82.1 per cent at 7 to 14 hours and 37.7 per cent at 15 hours or more, 36.1 per cent operated within 6 hours, avoidable delay in 36.5 per cent, unnecessary Doppler ultrasound in 9.7 per cent, contralateral fixation as standard practice, and the appendix testis or hydatid of Morgagni.)
  5. British Association for Sexual Health and HIV (BASHH): UK national guideline for the management of epididymo-orchitis, 2020 (Source for the discriminating features of epididymo-orchitis against torsion, the statement that colour duplex ultrasonography is not reliable enough to diagnose torsion because of a user-dependent false negative rate, and the recommendation that suspected clinical torsion should not undergo imaging but should have urgent scrotal exploration.)
  6. NHS: Testicle pain (Public safety-netting advice: attend A&E or call 999 for sudden severe pain in a testicle, testicle pain with nausea, vomiting or abdominal pain, or pain lasting more than an hour or present at rest.)
  7. BNF: Morphine (Source for the acute pain doses used here: adult 5 mg by slow intravenous injection every 4 hours, child 12 to 17 years 5 mg intravenously every 4 hours over at least 5 minutes, child 2 to 11 years 100 micrograms/kg intravenously every 4 hours over at least 5 minutes, with a reduced dose in frail and elderly patients and avoidance or dose reduction in renal impairment.)
  8. Royal College of Surgeons of Edinburgh: Urology, Testicular Torsion (Source for an incidence of around 1 in 4000 males under the age of 25 each year, and for three-point or four-point suture fixation at scrotal exploration.)
  9. Guy's and St Thomas' NHS Foundation Trust: Testicular torsion surgery (NHS patient information source for untwisting the testicle, stitching the other testicle in the same way, orchidectomy when the testicle cannot be saved, same-day or next-day discharge, no vigorous exercise for 4 to 6 weeks, no sexual activity for about 2 weeks, and urology follow-up at 6 to 8 weeks.)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.