Description

• Twisting of testis and spermatic cord, resulting in acute ischemia and loss of testis if unrecognized:
  • Intravaginal torsion: occurs within tunica vaginalis, only involves testis and spermatic cord
  • Extravaginal torsion: involves twisting of testis, cord, and processus vaginalis as a unit; typically seen in neonates
• System(s) affected: reproductive

Geriatric Considerations
Rare in this age group

Pediatric Considerations
Peak incidence at age 14 years (1)[B]

Epidemiology

Incidence

• ~1/4,000 males before age 25 years
• Predominant age:
  • Occurs from newborn period to 7th decade
  • 65% of cases occur in 2nd decade, with peak at age 14 years (1).
  • Second peak in neonates (in utero torsion usually occurs around week 32 of gestation) (1)

Etiology and Pathophysiology

• Initial incomplete twisting of spermatic cord causes venous obstruction, edema of testis, leading to ischemia.
• Complete twisting of the spermatic cord causes arterial occlusion, in addition to the above, leading to rapid ischemia.
• Congenital bell clapper deformity, which is bilateral in at least 2/5 of cases: A high mesorchium (the posterior lateral attachment of the testis to the tunica vaginalis) allows more room for the testis to twist within the tunica vaginalis and is associated intravaginal testicular torsion (2).
• No clear anatomic defect is associated with extravaginal testicular torsion:
  • In neonates, the tunica vaginalis is not yet well attached to scrotal wall, allowing torsion of entire testis including tunica vaginalis (1)[B].
• Usually spontaneous and idiopathic (1)[B]
• 20% of patients have a history of trauma.
• 1/3 have had prior episodic testicular pain.
• Contraction of cremaster muscle or dartos may play a role and is stimulated by trauma, exercise, cold, and sexual stimulation.
• Increased incidence may be due to increasing weight and size of testis during pubertal development.
• Possible alterations in testosterone levels during nocturnal sex response cycle; possible elevated testosterone levels in neonates (1)[B]
• Testis must have inadequate, incomplete, or absent fixation within scrotum (1)[B].
• Torsion may occur in either clockwise or counterclockwise direction.

Genetics

• Unknown
• Familial testicular torsion, although previously rarely reported, may involve as many as 10% of patients.

Risk Factors

• May be more common in colder months
• Paraplegia
• Previous contralateral testicular torsion