II. Epidemiology

  1. Annual Incidence: 1 in 4000 males under age 25 years
  2. Represents 10-20% of acute Scrotal Pain in boys
  3. Bimodal distribution (overall age range from young children to middle age men)
    1. Newborns
    2. Teens (age 12-18 years old represent 65% of cases)
      1. Most common in peri-pubertal teens

III. Pathophysiology

  1. Spermatic cord twists around its longitudinal axis
    1. Venous congestion
    2. Decreased arterial perfusion to Testicle, followed by Testicle ischemia and infarction
  2. "Bell Clapper" deformity results in excessive Testicle mobility, allowing spermatic cord to twist
    1. Responsible for torsion in 90% of cases
    2. Tunica vaginalis completely surrounds Testis
    3. Provides inadequate posterior fixation of Testis (allows for increased Testicle mobility within the tunica vaginalis)
    4. Testicular Torsion in this case occurs completely within tunica vaginalis (intravaginal torsion)
    5. Asymptomatic men have this on autopsy in 12% cases
    6. Usually results in intravaginal torsion
  3. Extravaginal torsion in neonates (external to tunica vaginalis)
    1. Occurs in utero or in perinatal period
    2. Entire spermatic cord including processus vaginalis twists
    3. Unilateral defect of incomplete attachment (unclear etiology)
      1. Gubernaculum and testicular tunics
      2. Dartos fascia

IV. Risk Factors

  1. Trauma (only responsible for 4-8% of cases)
  2. Most torsions have onset while sleeping
  3. Vigorous Exercise
  4. Prior episode of similar pain spontaneously resolved
  5. Testicular hypertrophy during Puberty
  6. Testicular Mass
  7. Cryptorchidism (Undescended Testicle)
  8. Long intrascrotal length of vas deferens
  9. Family History of torsion
  10. Hyperactive Cremasteric Reflex in Cold Weather
  11. Bell Clapper deformity (see pathophysiology above)

V. Symptoms: Children and Adults

  1. Sudden severe unilateral Scrotal Pain (thunder-clap pain)
    1. However, thunder-clap pain is not uniformly present
    2. If Trauma present, pain lasts >1 hour
    3. Keep high level of suspicion
    4. Presentation is within 24 hours in majority of cases (OR >4.2), and typically within 12 hours
    5. Testicular Torsion is cause of sudden unilateral Scrotal Pain in 16-42% of boys
    6. Intermittent pain may occur if the Testicle recurrently torses and detorses
    7. Painless Testicular Torsion may occur (if nerve is ischemic on twisting with vascular supply)
      1. Pain often improves or resolves after initial onset despite persistent torsion
      2. Pain typically returns due to inflammation related to infarct of the Testicle
  2. Nausea or Vomiting (OR >8.9, occurs in 90% of patients)
    1. More common in Testicular Torsion than in Epididymitis (whereas Dysuria is more common in Epididymitis)
  3. Lower Abdominal Pain or inguinal pain
    1. May be sole presentation in young boys
  4. Variants
    1. Chronic, recurrent intermittent torsion with pain lasting for hours and resolving spontaneously

VI. Symptoms: Newborns and Infants

  1. Infants may present only with unconsolable crying
  2. May present only with painless Scrotal Swelling

VII. Signs

  1. See Twist Score
  2. Precautions
    1. Examination is unreliable in Testicular Torsion (have a high index of suspicion, consider Ultrasound)
    2. Mellick (2012) Pediatr Emerg Care 28(1):80-6 +PMID: 22217895 [PubMed]
  3. Careful or wide based gait
  4. Testicle findings
    1. Left Testicle is more commonly affected than right
    2. Tender, firm affected Testicle
      1. Testicle is also diffusely tender in Epididymitis
    3. Testicle may appear to be retracted upward (high-riding, OR>18)
      1. However, a high riding Testicle is most commonly due to Epididymitis
    4. Testicle swollen and erythematous
      1. Venous Insufficiency precedes Arterial Insufficiency, resulting in edema
      2. Contrast with Torsion of Testicular Appendage, in which swelling is localized at superior pole
    5. Testicle may have horizontal lie
      1. Best seen with patient standing, while comparing each side
  5. Cremasteric Reflex absent (OR >4.8, unreliable)
    1. Testicle fails to rise in response to stroking or pinching upper medial thigh
    2. Most sensitive finding in Testicular Torsion (but only 60-70% Test Sensitivity and Test Specificity)
      1. Cremasteric Reflex is absent in 30% of normal males
      2. Presence of reflex suggests epidydimitis, however 25% without reflex also have epidydimitis
  6. Prehn's Sign Negative
    1. Elevation of Scrotum does not relieve pain, and may instead worsen pain
    2. Unreliable
      1. Positive finding does not exclude Testicular Torsion
      2. Negative finding may still be Epididymitis

VIII. Differential Diagnosis

  1. See Acute Testicular Pain
  2. See Groin Pain
  3. See Scrotal Mass
  4. See Chronic Testicular Pain
  5. Torsion of Testicular Appendage
    1. May be clinically indistinguishable from Testicular Torsion
    2. Local swelling and tenderness at the superior pole
    3. Scrotal Ultrasound is typically required to absolutely exclude Testicular Torsion
      1. Scrotal Ultrasound is used to identify Testicular Torsion
      2. Ultrasound is unlikely to identify Torsion of Testicular Appendage
  6. Epididymitis or Orchitis
    1. Rare in children prior to Puberty unless underlying genitourinary disorder (or recent Viral Infection)
    2. If Urinalysis is negative in prepubertal children, avoid treating with antibiotics
  7. Intermittent Torsion
    1. Acute, sudden severe Testicular Pain resolves in minutes and may only recurr after months to years
  8. Incarcerated Hernia
  9. Varicocele
  10. Scrotal Edema
  11. Ureteral Stone
  12. Small Bowel Obstruction
  13. Ureteral Stone
  14. Herpes Zoster
  15. Retrocecal Appendicitis

IX. Lab

  1. Urinalysis normal in 90% of patients
    1. Contrast with Epididymitis in which pyuria may be present
  2. C-Reactive Protein (CRP) normal (OR 124)
    1. Contrast with Epididymitis in which CRP is increased >24 mg/L in 96% of cases

X. Imaging

  1. Testicular Ultrasound with doppler (preferred)
    1. See Testicular Ultrasound
    2. Absent or decreased Blood Flow in Testicular Torsion
    3. Affected Testicle may appear enlarged
    4. Contrast with increased Blood Flow in Epididymitis
    5. Up to 25% of confirmed torsion cases still show flow on Doppler Ultrasound
    6. Efficacy
      1. Test Sensitivity: 88%
      2. Test Specificity: 90%
  2. Radionuclide scanning
    1. Findings
      1. Decreased perfusion in Testicular Torsion ("cold spots")
      2. Contrast with increased perfusion in Epididymitis ("hot spots")
    2. Efficacy
      1. Test Sensitivity: 100%
      2. Test Specificity: 97%
    3. Disadvantages
      1. Less readily available than Scrotal Ultrasound
      2. Radiation exposure (see Radiation Exposure in Medical Procedures)

XI. Precautions

  1. Consider occult Testicular Torsion if Undescended Testicle (especially in infants with unconsolable crying)
  2. Lower Abdominal Pain (without Testicular Pain) may be the only presenting symptom of Testicular Torsion in 30% of cases
    1. Atypical presentations are more common in prepubescent boys
    2. Always perform a testicular exam in male lower Abdominal Pain
    3. Gaither (2016) J Pediatric Urol 12(5): e1-291 [PubMed]
  3. Prehn's Sign and Cremasteric Reflex are unreliable and should not be used alone to rule-out Testicular Torsion
    1. No single exam finding either rules-in or rules-out Testicular Torsion
  4. Pain may have improved or resolved at presentation despite persistent Testicular Torsion
    1. Nerve becomes ischemic on twisting with vascular supply
    2. Pain recurs on testicular infarction with local inflammation
  5. High clinical suspicion for Testicular Torsion mandates early, emergent urologic evaluation
    1. Do not delay urologic evaluation for Scrotal Ultrasound in high clinical suspicion cases
    2. Urgent evaluation is critical, but time >6 hours does not exclude potential salvage (50% salvage rate at 6-48 hours)
      1. Do not deny or delay surgery based on delayed presentation
      2. Testicle may still be salvageable even after 24 hours in partial or intermittent torsion
    3. Negative Ultrasound should not obviate emergent urological evaluation if clinical suspicion remains high
      1. Scrotal Ultrasound has a 1% False Negative Rate for torsion (6 to 14% in some studies)
      2. Ultrasound Test Sensitivity is decreased in small, prepubertal Testes
      3. Early Ultrasound may have normal Doppler Ultrasound
        1. First hour may have normal flow despite torsion
        2. Testicular Swelling and hypoechoic Ultrasound may not appear for first 4-6 hours
      4. Intermittent torsion may occur (but be absent at Ultrasound)
        1. Ultrasound Test Sensitivity is 75% in intermittent torsion (whirlpool sign may be seen)
        2. Intermittent torsion is most often a clinical diagnosis based on history
  6. Twist Score may assist with diagnosis
    1. See Twist Score
    2. Total Score >5
      1. Emergent Urologic Consultation without delay (surgical exploration regardless of Ultrasound)
    3. Total Score 2 to 5
      1. Testicular Ultrasound with flow
    4. Total Score <2
      1. Testicular Torsion unlikely

XII. Evaluation

  1. Pain <6 hours and history and exam and /or Ultrasound findings suggest Testicular Torsion
    1. Immediate urologic surgery for detorsion
  2. Pain >6 hours or diagnosis uncertain
    1. Doppler Ultrasound of Scrotum (if not already done)
    2. Consult Urology for findings consistent with torsion

XIII. Management

  1. Maintain high index of suspicion
  2. Immediate surgical Consultation
    1. Surgical exploration (within 6 hours) is critical for suspected Testicular Torsion
      1. However, testicular salvage may be as high as 50% at 6 to 48 hours (see salvage times as below)
    2. Definitive detorsion is goal
    3. Informed Consent for surgery includes the significant risk of orchiectomy
      1. Non-viable or necrotic Testicle in up to 39-71% of cases
    4. Prophylactic orchiopexy of contralateral side
      1. Prevents recurrence of torsion on opposite side
      2. Performed in most cases of Bell-Clapper deformity (affects both Testicles in 80% of cases)
      3. Performed in most cases of neonatal Testicular Torsion (extravaginal torsion)
  3. Attempt manual detorsion by rotating Testicle pedicle (do not delay surgery)
    1. Important
      1. Obtain Testicular Ultrasound with doppler after detorsion attempt
      2. Manual detorsion temporarily corrects problem
        1. Consider if >6 hours before specialist can correct
        2. Lifting Testicle may also temporize by alleviating pain and allowing reperfusion
      3. Manual detorsion does not obviate surgery
        1. Surgery required for definitive resolution
        2. Non-viable Testicle must be removed
        3. Prophylactic orchiopexy of contralateral side
    2. Position patient in supine position
    3. Give analgesia (e.g. Ibuprofen, Acetaminophen, Hydromorphone, Morphine, Fentanyl, Oxycodone) at least 20 minutes before procedure
    4. Pre-Anesthetic (patient needs to maintain some alertness to express pain relief)
      1. Intravenous light Conscious Sedation or
      2. Local 2% Lidocaine injected into vas deferens
    5. Consider Testicular Torsion Traction Technique before rotation
      1. Grasp the Torsed Testicle and stretch the spermatic cord to maximal length
      2. Testicle may naturally rotate as the cord us stretched
    6. Externally rotate Testicle away from midline (medial to lateral)
      1. Grasp Testicle between thumb and index finger
      2. Externally rotate affected Testicle as if opening a book (medial torsion)
        1. Rotate right Testicle counter-clockwise or
        2. Rotate left Testicle clockwise
      3. Rotate at least 180 degrees (typically more than 360 degrees is required)
        1. More than one turn may be required
        2. Continue until pain relief and stop if pain worsens
        3. Scrotal Doppler Ultrasound can confirm return of Blood Flow
          1. However normal flow may not immediately return despite successful detorsion
        4. If unsuccessful rotating Testicle in open book fashion (or pain increases with external rotation)
          1. Consider rotating in opposite direction (internal rotation, closing book)
          2. Up to one third of torsions are lateral torsions (reduced with internal rotation)
      4. Efficacy
        1. Successful in 26-80% of torsion cases
    7. References
      1. Cornel (1999) BJU Int 83:672-4 [PubMed]

XIV. Prognosis

  1. Orchiectomy risk
    1. Orchiectomy for non-viable or necrotic Testicle occurs in 39-71% of cases
    2. Most significant risk factors for orchiectomy include older age and duration of torsion (see below)
  2. Testes salvage is time dependent on Restored Blood Flow
    1. Restored in 6 hours: 80-100% of Testes salvaged
    2. Restored in 12 hours: 50-60% of Testes salvaged
    3. Restored >24 hours: 10-20% of Testes salvaged
    4. Testicular function and fertility may be chronically reduced despite testicular salvage
  3. Neonatal torsion
    1. Poor salvage rate of 9%
    2. Nandi (2011) Pediatr Surg Int 27(10): 1037-40 [PubMed]
  4. References
    1. Barada (1989) J Urol 142:746-8 [PubMed]

XV. References

  1. Claudius, Behar and Lockhart (2017) EM:Rap 17(10): 3
  2. Cristoforo (2019) Crit Dec Emerg Med 33(10): 15-20
  3. Herman and Arhancet (2020) Crit Dec Emerg Med 34(10): 17-21
  4. Mace (2021) Crit Dec Emerg Med 35(9): 14-5
  5. Mason and Jones in Herbert (2016) EM:Rap 16(9):10
  6. Mellick and Swaminathan (2023) EM:Rap 23(3): 12-3
  7. Weinstock in Herbert (2017) EM:Rap 17(12): 4-5
  8. Langan (2022) Am Fam Physician 106(2): 184-9 [PubMed]
  9. Lewis (1995) J Pediatr Surg 30:277-82 [PubMed]
  10. Hawtrey (1998) Urol Clin North Am 25:715-23 [PubMed]
  11. Ringdahl (2006) Am Fam Physician 74:1739-46 [PubMed]
  12. Sharp (2013) Am Fam Physician 88(12): 835-40 [PubMed]

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