Reproductive · PANCE / PANRE

Testicular Torsion

Twisting of the spermatic cord — surgical emergency; salvage rate falls rapidly after 6 hours of ischemia.

Also known as: testicular torsion, spermatic cord torsion, torsion

Overview

Twisting of the spermatic cord causing compromise of testicular blood flow. Two anatomic subtypes: intravaginal (within tunica vaginalis; most common, due to 'bell-clapper' deformity) and extravaginal (entire testis and tunica twist; characteristic of neonates).

Epidemiology

Annual incidence ~1 in 4,000 males under 25 years. Bimodal peaks: neonatal (extravaginal) and adolescent (12-18 years; intravaginal). Accounts for ~10-15% of acute scrotum presentations.

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Risk factors

  • Bell-clapper deformity (horizontal lie of testis; transverse fixation of tunica vaginalis on cord — present bilaterally in most cases)
  • Cryptorchidism / undescended testis
  • Prior intermittent torsion
  • Trauma (in some cases — torsion can be spontaneous)
  • Cold weather, exercise, sleep (cremaster contraction)
  • Family history
  • Increased testicular size (puberty)

Pathophysiology

Spermatic cord twists, occluding venous drainage first (more compressible), then arterial inflow → ischemia → infarction. Salvage rate strongly correlates with duration of torsion: ~95% at <6 hours, ~50% at 6-12 hours, <20% at >24 hours. Bilateral fixation prevents future torsion of contralateral testis.

Clinical presentation

Symptoms

  • Sudden onset severe testicular pain (often while sleeping, exercising, or after trauma)
  • Nausea and vomiting (common — distinguishes from epididymitis)
  • Referred lower abdominal or inguinal pain (may be the chief complaint, especially in younger boys — examine the scrotum)
  • Previous episodes of similar pain that resolved (intermittent torsion)

Signs / physical exam

  • High-riding testis with transverse lie
  • Diffusely tender, swollen, edematous, erythematous hemiscrotum
  • Absent cremasteric reflex on affected side (highly sensitive — stroking inner thigh fails to elevate testis)
  • Negative Prehn sign (no relief with elevation; relief is more consistent with epididymitis)
  • Possibly palpable 'knot' of cord above testis
  • Reactive hydrocele in late presentation

Classic findings

Adolescent boy with sudden severe testicular pain, nausea/vomiting, high-riding testis with transverse lie, absent cremasteric reflex.

Differential diagnosis

  • Epididymitis / epididymo-orchitis — Gradual onset, fever, dysuria; positive Prehn sign (relief with elevation); preserved cremasteric reflex; older or sexually active patients
  • Torsion of testicular/epididymal appendage — Younger boys (7-12 yo), localized tenderness at upper pole, 'blue dot sign'; self-limited
  • Inguinal hernia (incarcerated/strangulated) — Mass extending into scrotum from inguinal canal
  • Scrotal trauma (hematocele, testicular rupture) — Trauma history; ultrasound
  • Henoch-Schönlein purpura with scrotal involvement — Palpable purpura, abdominal pain, arthralgia, hematuria
  • Idiopathic scrotal edema — Bilateral edema, erythema; afebrile; self-limited; usually pre-pubertal
  • Testicular tumor — Painless mass; can present with acute pain if hemorrhage; ultrasound
  • Varicocele (acute) — 'Bag of worms,' more on left; usually painless or dull ache

Diagnostic workup

Diagnostic criteria

Clinical diagnosis when classic — proceed directly to surgical exploration. Ultrasound for equivocal presentations.

Labs

  • Urinalysis — typically negative (pyuria favors epididymitis)
  • CBC, BMP, type and screen if surgical exploration planned

Imaging

  • Color Doppler ultrasound — first-line imaging when diagnosis uncertain; shows decreased or absent blood flow in affected testis; sensitivity ~88-95%
  • DO NOT delay surgical exploration for imaging if clinical suspicion is high
  • TWIST score (Testicular Workup for Ischemia and Suspected Torsion): 0-2 low risk, 3-4 intermediate (US needed), 5-7 high risk (proceed to OR)

Diagnostic algorithm

flowchart TD
  A[Acute scrotal pain<br/>± nausea, vomiting] --> B[Focused exam:<br/>cremasteric reflex,<br/>testis lie, tenderness,<br/>Prehn sign]
  B --> C{High clinical<br/>suspicion for torsion?}
  C -->|High TWIST 5-7<br/>or classic exam| D[Urology STAT —<br/>OR for detorsion +<br/>bilateral orchiopexy]
  C -->|Intermediate<br/>TWIST 3-4| E[Color Doppler US]
  E -->|Decreased/absent flow| D
  E -->|Normal flow| F[Consider epididymitis,<br/>torsion of appendix,<br/>other causes]
  C -->|Low TWIST 0-2| F
  D --> G{Testis viable?}
  G -->|Yes| H[Detorse + bilateral<br/>orchiopexy 3-point fixation]
  G -->|No| I[Orchiectomy +<br/>contralateral orchiopexy]
  F --> J[Treat per diagnosis<br/>± antibiotics, NSAIDs,<br/>follow-up]
Acute scrotum algorithm — high suspicion goes directly to OR; do not delay surgery for imaging.

Treatment

First-line

  • Emergent surgical exploration — do not delay for imaging if clinical picture is classic
  • Time from onset to detorsion is the key prognostic factor
  • Manual detorsion may be attempted as temporizing measure: 'open book' technique — rotate testis laterally (outward) for affected side (most torsions are medial); 1.5-2 full turns; relief of pain and descent of testis indicate success — DOES NOT replace surgery
  • Surgical detorsion + bilateral orchiopexy (3-point fixation of both testes to scrotal wall to prevent recurrence)
  • Orchiectomy if testis is nonviable after detorsion and brief observation

Neonatal torsion (extravaginal)

  • Often diagnosed in utero or at birth — firm, dark, fixed scrotal mass
  • Affected testis is usually nonviable
  • Surgical management is controversial — some recommend prompt exploration with orchiopexy of contralateral side to prevent asynchronous torsion
  • Bilateral exploration during the same procedure is standard

Intermittent torsion

  • Recurrent self-resolving episodes of similar pain
  • Even if testis appears normal between episodes, elective bilateral orchiopexy is recommended
  • Highest risk for future complete torsion

Torsion of appendix testis (mimic)

  • Usually pre-pubertal boys
  • Localized upper-pole tenderness, 'blue dot sign' through skin
  • Cremasteric reflex preserved
  • Doppler shows normal testicular flow
  • Conservative management: NSAIDs, rest; self-resolves in 5-10 days

Complications

  • Loss of testis (orchiectomy)
  • Subfertility / infertility — even after successful detorsion, sympathetic effects on contralateral testis can impair spermatogenesis
  • Testicular atrophy after delayed detorsion
  • Recurrent torsion if orchiopexy not performed
  • Psychological impact on adolescent body image

PANCE pearls

  • Testicular torsion is a SURGICAL EMERGENCY — call urology immediately and do not delay surgery for imaging if the diagnosis is clinically apparent.
  • Salvage rate is >90% if detorsion occurs within 6 hours; <50% by 12 hours; <20% by 24 hours.
  • Always examine the scrotum in any boy or young man with abdominal or groin pain — torsion can present with referred pain.
  • Absent cremasteric reflex on the affected side is the most sensitive clinical finding for torsion in adolescents.
  • Manual detorsion is rotated like 'opening a book' (laterally/outward) — but this is only a temporizing measure; surgical orchiopexy is still required.
  • Bilateral orchiopexy at surgery is standard — bell-clapper deformity is usually bilateral.
  • Suspect torsion in any neonate with a firm, discolored hemiscrotum from birth; in this age group most testes are nonviable, but contralateral fixation is important.
  • Repeated self-resolving episodes of acute testicular pain (intermittent torsion) warrant elective bilateral orchiopexy.

References

  • AUA 2023 — American Urological Association Educational and Clinical Statements on Acute Scrotum
  • EAU 2024 — EAU Guidelines on Pediatric Urology — Acute Scrotum (2024)
  • TWIST Score — Sheth KR et al., Development and Validation of the TWIST Score for the Diagnosis of Testicular Torsion (J Urol 2016)

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