Testicular Torsion

Meet the patient

A 15-year-old boy is woken at 3am by sudden, severe left testicular pain. He has vomited twice on the way in. The left testis is high-riding, lies horizontally, and is exquisitely tender; the cremasteric reflex is absent on the left and present on the right.[1][2]

Two questions decide his next hour, and they decide every torsion stem: is this torsion? (the bedside triad answers in seconds) and can I get him to theatre within 6 hours of onset? (the clock decides whether he keeps the testis). Hold those two and the whole topic falls into place.[1]

Time is testis — the 6-hour rule

Torsion is the one urological diagnosis where minutes decide the outcome. The salvage gradient is the single most examined number set in the topic, and it is unforgiving:[1][4]

Tissue injury becomes irreversible after about 6 to 8 hours of complete arterial occlusion — first haemorrhagic, then gangrenous. The determinant of outcome is duration of torsion before detorsion, not arrival time, not transfer status, not who pays.[1]

The outcome proof is a 5-year paediatric series of 114 patients: overall salvage was 55 percent, and on multivariate analysis the only independent predictor of salvage was symptom duration under 6 hours (odds ratio 22.5). Inter-hospital transfer, time of day, insurance and ethnicity did not matter on their own. Duration is king.[4]

The examinable consequence is hard: any adolescent or young adult male with acute testicular pain has torsion until proven otherwise, and the burden of proof falls on the clinician who would not explore.[1]

The bell-clapper — bilateral, so always fix the other side

Nearly all adolescent torsion runs on one anatomical fault: the bell-clapper deformity. In normal anatomy the tunica vaginalis reflects onto the epididymis and posterolateral testis, anchoring the gland to the posterior scrotal wall. In the bell-clapper deformity the tunica invests the cord itself too high, so the testis, epididymis and a length of cord hang freely suspended within the tunica — like the clapper inside a bell — and nothing tethers them.[1]

Because the deformity is embryological, it is usually bilateral — present in roughly 12 percent of anatomical specimens. That single fact drives the non-negotiable rule of the operation: fix the contralateral testis at every torsion operation, because the other side can torsion at any time and metachronous loss of the only remaining testis is catastrophic.[1]

The three clinical forms, separated by where the twist sits and who it hits:[1]

[1]

The degree of rotation matters at surgery: a partial twist (less than 360 degrees) may permit trickle flow and a subacute course, while 360 to 720 degrees (one to two full turns) abolishes flow within minutes.[1]

How common, who, and why the cord twists

The incidence is low in the population and high on the exam — about 1 in 4,000 males under 25 years per year, with a bimodal age distribution: a small neonatal peak (extravaginal) and a much larger adolescent peak between 12 and 18 years.[1][2]

[1] [2]

The bell-clapper is the dominant risk factor, but the precipitants examiners expect you to name:[1][2]

• Undescended testis (cryptorchidism): torsion of an intra-abdominal or inguinal testis is about ten times more common than of a scrotal testis. An empty hemiscrotum plus acute abdominal or groin pain is torsion of the undescended testis until proven otherwise.
• Puberty and rapid testicular growth — the adolescent spurt raises the mass-to-pedicle ratio, the explanation for the age peak.
• A prior episode that resolved spontaneously — intermittent torsion; the strongest historical predictor of a future complete torsion.
• Trauma and strenuous exercise — may trigger torsion in an already bell-clapper testis; the history usually shows pain began before or out of proportion to the injury.
• Cold ambient temperature and sleep — both provoke cremasteric contraction, the mechanical trigger; a winter predilection is described.[1][2]

The mechanical cascade — why the testis dies

Once the cord twists, the sequence is mechanical and predictable — and it is exactly the salvage window.[1][2]

1. Trigger. A sudden cremasteric contraction (spontaneous, in sleep, after trauma or exercise, or in cold) rotates the mobile testis. Torsion is medial in about two-thirds — the testis rotates "like closing a book."
2. Venous and lymphatic occlusion. The thin-walled, low-pressure pampiniform veins compress first. Venous outflow is abolished while arterial inflow continues, producing venous congestion, interstitial oedema, and progressive swelling inside the non-compliant tunica albuginea.
3. Arterial occlusion. Rising intra-tunical pressure and direct kinking compress the thicker, higher-pressure testicular artery. Once inflow stops the testis is truly ischaemic.
4. Infarction. After about 6 to 8 hours of complete arterial occlusion, injury becomes irreversible — haemorrhagic, then frankly gangrenous. Beyond 24 hours the gland is necrotic.[1]

Two operative consequences follow. First, the degree of torsion matters: 720 degrees abolishes flow within minutes, while a partial twist may permit trickle flow and a subacute course. Second, because venous occlusion precedes arterial occlusion, a testis torsed for only a few hours may look congested and blue yet recover fully once detorsed — whereas one torsed beyond 12 hours is typically black, flaccid and non-viable. The intra-operative choice between orchidopexy and orchidectomy rests on that viability assessment.[1]

The classic triad — sudden pain, absent cremasteric, high-riding

Three bedside findings make the diagnosis, and they take seconds.[1]

[1]

The visceral accompaniments are highly suggestive: nausea and vomiting occur in the majority via the testicular visceral afferent pathway (T10 to L1), and their presence with acute scrotal pain substantially raises the likelihood of torsion. Lower abdominal or groin pain is common (genitofemoral and ilioinguinal referral), and a few patients present with abdominal pain and minimal scrotal complaint.[1]

Late signs — scrotal swelling, erythema, a reactive hydrocoele, low-grade fever — develop over hours as oedema and inflammation progress; their absence early does not exclude torsion. Urinary symptoms are typically absent; pyuria favours epididymitis, but a sterile urine with acute pain favours torsion.[1]

Atypical presentations — the traps that bite

The missed torsion is almost always an atypical one, and the atypical presentations are the source of litigation. Examiners probe them for that reason.[2][8]

• Abdominal or groin pain with an unremarkable scrotum — torsion of an undescended (inguinal or intra-abdominal) testis can present as acute abdomen or a tender groin lump with an empty hemiscrotum. Always examine the scrotum in any male with acute abdominal pain.
• Pain that seems to have settled — an intermittent torsion that has spontaneously detorsed may leave a near-asymptomatic patient; the history of sudden severe pain that resolved is itself the red flag.
• Trauma — a torsion precipitated by minor trauma is attributed to the injury. Pain disproportionate to the mechanism, or a high-riding testis on the injured side, should prompt exploration.
• "Epididymitis" in a male under 25 — torsion is more likely than epididymitis in this group, and the cremasteric reflex is the discriminator.
• The neonate — not pain but a painless, hard, discoloured (blue-black) scrotal mass, irritability and reluctance to feed: extravaginal, prenatal torsion.[2][8]

The acute scrotum differential — torsion versus epididymitis

The differential is short, but the stakes are high, and the one decision that matters is torsion versus epididymo-orchitis — overlapping age and appearance, opposite management.[1][2]

[1] [2] [8]

Three deserve specific comment. Torsion of the appendix testis (hydatid of Morgagni) gives the blue dot sign — a small dark area at the upper pole seen through the scrotal skin; pain is less severe, the testis lies normally, the cremasteric reflex is preserved, and management is conservative once testicular torsion is excluded.[8] Epididymo-orchitis is the great mimic — gradual over days, fever, pyuria, a tender epididymis, a preserved cremasteric reflex and pain relieved by elevation — but in any young male with acute unilateral pain, torsion remains the default until excluded.[1] Incarcerated hernia is distinguished by the inability to get above the swelling and by bowel obstruction.[1]

Diagnosis is clinical — do NOT delay surgery for a Doppler

The single most dangerous error in this topic is waiting for imaging when the picture is classic. A false-negative ultrasound in a convincing history is the route to an avoidable orchidectomy and a lawsuit.[1]

[1]

When imaging is genuinely needed, colour Doppler ultrasonography is the modality of choice. The positive finding is absent or markedly reduced intratesticular flow on the affected side compared with the contralateral testis. Reported sensitivity is around 95 percent and specificity around 92 percent in systematic review — but performance is operator-dependent and falls in small, partially-torsed or prepubertal testes, where baseline flow is low.[3]

The crucial caveat is that false negatives occur: partial torsion, spontaneous detorsion at the moment of scanning, and slow collateral flow can all produce an apparently normal Doppler. Systematic review concluded that combined grey-scale (B-mode) and colour Doppler outperform either alone, but emphasised ultrasound must always be read with the clinical picture, never in isolation.[3]

Bedside and laboratory tests are adjuncts only. Urinalysis helps exclude epididymo-orchitis (pyuria, nitrites), but mild pyuria does not exclude torsion. FBC and CRP support infection when markedly raised but do not exclude torsion. Once the decision to operate is made, take group and save, coagulation and beta-hCG. Scrotal exploration is itself the definitive investigation — a negative exploration is acceptable and far safer than a missed torsion.[1]

TWIST 5-7 = explore without imaging

The Testicular Workup for Ischaemia and Suspected Torsion (TWIST) is a 7-point bedside score that stratifies torsion from history and examination alone.[5][6]

[5]

The Barbosa risk stratification turns the score into action:[5]

• 0 to 2 — low risk: torsion unlikely; observe, ultrasound if needed.
• 3 to 4 — intermediate risk: ultrasound mandatory, with surgical backup.
• 5 to 7 — high risk: proceed to immediate surgical exploration without imaging.[5]

A meta-analysis of nine prospective studies found the Barbosa cut-points achieved an area under the receiver operating curve of 0.92, with a low-risk sensitivity of 0.98 (effectively ruling torsion out) and a high-risk specificity of 0.97 (effectively ruling it in). The intermediate group remained genuinely uncertain and required ultrasound.[5] The score, originally paediatric, has been validated in adults with comparable accuracy — extending its use across the age range.[6]

Treat TWIST as decision support, not a substitute for surgical judgement. In a high-suspicion setting with an experienced surgeon, exploration remains the default regardless of the score.[1]

The theatre bundle — analgesia, NBM, mark the side

There is no resuscitative delay for torsion: the moment the diagnosis is entertained, the patient is on a path to theatre. The bundle is small and pragmatic, and every step that delays the knife is a step of ischaemia.[1][2]

• Analgesia: IV opioid — morphine 0.1 mg/kg (typical adult 5 to 10 mg) titrated, or fentanyl 1 mcg/kg, with an antiemetic. Adequate analgesia is humane and also facilitates manual detorsion if attempted.
• Antiemetic: ondansetron 4 mg IV (or 0.1 mg/kg in children) for nausea and to protect the fasted state.
• Keep nil by mouth from the decision; confirm last oral intake for anaesthetic fasting.
• Consent — for scrotal exploration with orchidopexy or orchidectomy, explicitly including loss of the testis and routine fixation of the contralateral side; document the time-critical discussion.
• Mark the side with the patient awake — operating on the wrong testis is a surgical never-event.
• Theatre alert — notify the operating team and anaesthetist immediately; torsion is a Category 1 (immediate) emergency.
• Antibiotic on induction — cefazolin 1 to 2 g IV (or 25 to 50 mg/kg in children), particularly if orchidectomy for a necrotic testis is anticipated.
• NSAID adjunct — diclofenac 75 mg IM/IV where available may supplement analgesia, but must not replace opioid in severe pain.[1]

Open the book — the detorsion direction and the operative steps

The standard of care is immediate scrotal exploration, ideally within 6 hours of onset. Because torsion is medial in about two-thirds of cases, the corrective detorsion is lateral and outward — "opening the book." The operative sequence:[1]

1. Approach. A transverse hemiscrotal incision (or a single midline raphe incision to reach both sides) through skin, dartos and tunica vaginalis; deliver the testis.
2. Detorsion. Manually untwist the cord outward, "opening the book." If direction is unclear, untwist until the testis looks least congested, then confirm by return of flow. Wrap in warm saline-soaked gauze and watch for pink colour and bleeding.
3. Assess viability — the critical intra-operative judgement. A testis that pinks up and bleeds briskly from an incision of the tunica albuginea is viable; a black, flaccid, non-bleeding testis is non-viable. If uncertain, incise the tunica and observe; some surgeons apply warm packs and wait. There is no universally agreed threshold — a "save at all costs in the young" approach is reasonable, because the downside of leaving a borderline testis (atrophy) is less severe than losing a recoverable one.
4. Orchidopexy (if viable). Fix with non-absorbable sutures — classically 3-0 or 4-0 polypropylene or Ethibond, three to four points through the tunica albuginea and dartos. Some surgeons add a dartos pouch.
5. Orchidectomy (if non-viable). Divide and ligate the cord at the external ring — vas and vessels separately — and send for histology. Offer and document a testicular prosthesis (silicone), usually as a later elective sitting.
6. Contralateral orchidopexy. Always fix the opposite testis in the same anaesthetic, using the same non-absorbable technique — the bell-clapper is bilateral and metachronous loss of the only remaining testis is unacceptable. This is one of the few absolutely non-negotiable steps in urology.[1]

The classic trap: absorbable sutures for orchidopexy. They resorb, fixation fails, and the testis retorses. Non-absorbable is mandatory, and it is the explanation for any "recurrent" torsion after a previous fixation.[1]

Open the book at the bedside — manual detorsion as a bridge

When theatre access is delayed — rural setting, list backlog, prolonged transfer — manual detorsion at the bedside or in ED can restore flow as a temporising measure. It is a bridge, never a cure; the testis must still be explored and fixed in the same admission.[1][2]

• Give IV analgesia and procedural sedation as needed.
• Grasp the testis and rotate it medial to lateral, outward — "opening the book" — because torsion is usually medial. One to two full rotations may be needed.
• Success is signalled by abrupt pain relief and a softer, lower-riding testis. If pain worsens, the torsion was lateral (about one in three) — reverse the direction.
• Success rates of 25 to 80 percent are reported; even after successful detorsion, explore and fix the testis, because retorsion is common and partial detorsion can leave compromised flow.[1][2]

[1] [2]

Neonates, undescended, intermittent — the subtypes that change the plan

Extravaginal (neonatal) torsion. The whole cord and its coverings twist before the tunica fuses to the scrotal wall. Presentation is a painless, hard, discoloured scrotal mass at birth; the testis is usually already infarcted. The operation is for diagnosis, removal, and contralateral protection. Modern practice favours early contralateral scrotal exploration and orchidopexy to exclude asynchronous torsion and protect the only remaining gonad; bilateral prenatal torsion is catastrophic (anorchia) and rare.[1][2]

Torsion of an undescended testis carries a roughly tenfold higher risk. Presentation is acute abdominal or groin pain with an empty scrotum and a tender groin lump — a frequently missed diagnosis. Always palpate the scrotum in any male with acute abdominal pain. Management is urgent exploration (inguinal approach for an inguinal testis), detorsion, and orchidopexy to the scrotum if viable or orchidectomy if not.[1]

Torsion of testicular appendages. The appendix testis (hydatid of Morgagni) and appendix epididymis — Müllerian and Wolffian remnants — can themselves torsion, especially in prepubertal boys. The picture is less severe: gradual onset, normal lie, preserved cremasteric reflex, and the blue dot sign at the upper pole. Once testicular torsion is excluded, management is conservative — rest, scrotal support, and an NSAID such as ibuprofen 5 to 10 mg/kg orally; the infarcted appendage atrophies over one to two weeks.[8]

Intermittent torsion — recurrent self-limiting episodes, often in adolescence. A normal Doppler in the pain-free interval does not exclude it. The management is elective bilateral orchidopexy to prevent a catastrophic complete torsion.[1]

How torsion patients come to harm — the preventable list

Every item on this list is an avoidable loss that has ended in litigation.[1]

[1]

Disease complications track the same biology: testicular atrophy (5 to 40 percent even after "successful" salvage, depending on ischaemia time); infertility and subfertility in a subset (reduced count, motility, morphology); infection and sepsis if a necrotic testis is retained; and the psychological and cosmetic impact of losing a testis in a young man, for which a prosthesis should be offered and discussed sensitively.[1][4]

Fertility, follow-up and the other testis

Even when the torsed testis is removed, the contralateral testis is at risk of subsequent subfertility. Breakdown of the blood-testis barrier during ischaemia, and reactive changes after orchidectomy, are associated with antisperm antibody formation and a measurable decline in semen parameters in a subset of patients; the magnitude remains debated, but it is the rationale for offering baseline and follow-up semen analysis after an episode of torsion.[7]

Disposition is brief because the operation is the event. After orchidopexy, discharge within 24 hours with scrotal support, oral analgesia, and advice to avoid strenuous activity for 4 to 6 weeks; review at 1 to 2 weeks for wound check and at 3 to 6 months for testicular size (atrophy surveillance). After orchidectomy, add an early discussion about a testicular prosthesis (usually 6 to 12 months later, once swelling settles). Offer baseline semen analysis at 3 to 6 months, repeated at 12 months, with andrology referral if abnormal.[7]

Regional and resource deltas

The unresolved controversies: how long a borderline testis may be left in situ in the hope of recovery (increasingly, surgeons leave it and accept a risk of atrophy, since orchidectomy is irreversible); whether to fix the contralateral side in neonatal torsion (modern practice favours it); and the magnitude of antisperm-antibody-mediated contralateral injury.[7]

The mantra, and the mnemonic

The mantra: time is testis — explore, do not image. When the picture is classic, the only test that helps the patient is the scrotal incision.[1]

Ward-round test — three stems, thirty seconds each

Stem 1 — the 15-year-old from the top of the topic (answer)

The boy woken at 3am with sudden severe left testicular pain, vomiting, a high-riding horizontal testis and an absent cremasteric reflex. The registrar suggests a Doppler "to confirm". What is the right next 30 minutes? Model: This is classic torsion — the bedside triad is complete. Do NOT wait for imaging. Give IV morphine 0.1 mg/kg with ondansetron 4 mg IV, keep him nil by mouth, consent for scrotal exploration with possible orchidectomy and contralateral orchidopexy, mark the left side with the patient awake, give cefazolin on induction, and get him to theatre inside the 6-hour window. The Doppler is for the equivocal case in which it will not delay theatre; this is not that case.[1]

Stem 2 — the 13-year-old with pain that 'settled' (answer)

A 13-year-old had sudden severe testicular pain at school that resolved completely before arrival. He is now asymptomatic with a normal Doppler. The registrar plans to discharge him. Model: This is intermittent torsion until proven otherwise — the history of sudden severe pain that resolved is the red flag, not reassurance. A normal Doppler in the pain-free interval does not exclude it. Admit, obtain a urology review, and offer elective bilateral orchidopexy to prevent a future complete, non-detorsing episode. Discharging him without a fixation plan is how a testis is lost next time.[1]

Stem 3 — the hard testis at 24 hours (answer)

A 16-year-old presents 26 hours after onset. At exploration the testis is black, flaccid and does not bleed on incising the tunica albuginea. What do you do, and what do you say to him? Model: The testis is non-viable. Perform orchidectomy, ligating the vas and vessels separately at the external ring, send for histology, and — critically — fix the contralateral testis with non-absorbable sutures, because the bell-clapper is bilateral and he must not lose the other side. Counsel him sensitively about the loss, offer a testicular prosthesis (usually 6 to 12 months later), and arrange baseline semen analysis at 3 to 6 months with follow-up, because antisperm-antibody-mediated subfertility is a recognised late consequence.[1][7]

References

1. [1]Sharp VJ, Kieran K, Arlen AM. Testicular torsion: diagnosis, evaluation, and management Am Fam Physician, 2013.PMID 24364548
2. [2]Laher A, Ragavan S, Mehta P, Adam A. Testicular Torsion in the Emergency Room: A Review of Detection and Management Strategies Open Access Emerg Med, 2020.PMID 33116959
3. [3]McLaren PSM. A systematic review on the utility of ultrasonography in the diagnosis of testicular torsion in acute scrotum patients Radiography (Lond), 2021.PMID 33451883
4. [4]Ramachandra P, Palazzi KL, Holmes NM, Marietti S. Factors influencing rate of testicular salvage in acute testicular torsion at a tertiary pediatric center West J Emerg Med, 2015.PMID 25671040
5. [5]Qin KR, Qu LG. Diagnosing with a TWIST: Systematic Review and Meta-Analysis of a Testicular Torsion Risk Score J Urol, 2022.PMID 35238603
6. [6]Barbosa JABA, de Freitas PFS, Carvalho SAD, et al. Validation of the TWIST score for testicular torsion in adults Int Urol Nephrol, 2021.PMID 32844355
7. [7]Aggarwal D, Parmar K, Sharma AP, et al. Long-term impact of testicular torsion and its salvage on semen parameters and gonadal function Indian J Urol, 2022.PMID 35400863
8. [8]Davis JE, Silverman M. Scrotal emergencies Emerg Med Clin North Am, 2011.PMID 21782069