Summary

Testicular torsion is the sudden twisting of the spermatic cord within the scrotum. It most commonly affects neonates and young men. Because of the risk of ischemia and possible infarction of the testis, it is considered a urological emergency. Testicular torsion is characterized by sudden-onset unilateral testicular pain, which may radiate to the lower abdomen, with nausea and vomiting. Clinical findings include a high-riding testis with an absent cremasteric reflex. Imaging with duplex ultrasound of the scrotum may be required if the clinical diagnosis is in doubt. If testicular torsion is suspected, prompt surgical exploration within six hours of symptom onset is essential to salvage the testis. Important differential diagnoses, e.g., orchitis and epididymitis, should be ruled out before initiating treatment.

Epidemiology

Peak incidence: neonatal period (first 30 days of life) and during puberty

References:^[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Idiopathic
- Hypotheses include the bell-clapper deformity (intravaginal torsion; see "Pathophysiology" below) or a prolonged mesorchium
- In neonates, the entire tunica vaginalis undergoes torsion (extravaginal torsion).
Iatrogenic
Occurs in very rare cases as a result of trauma

References:^[1]^[2]^[3]

Pathophysiology

Testicular torsion involves a sudden twisting of the spermatic cord associated with a poorly secured testicle.
Torsion result in venous engorgement with consequent arterial compromise, tissue ischemia, and possible infarction. Irreversible damage occurs after approx. 6–12 hours of torsion.

References:^[1]^[2]

Clinical features

Abrupt onset testicular pain and/or pain in the lower abdomen
- Typically swollen and tender testicle and/or lower abdominal tenderness
Nausea and vomiting
Abnormal position of testicle
- Abnormal transverse lie
- Scrotal elevation
- Possible undescended testes (predisposes to testicular torsion)
Absent cremasteric reflex
Prehn sign: negative

Testicular torsion should always be suspected in a male patient with severe, sudden-onset testicular pain!

References:^[1]^[4]^[5]

Diagnostics

Testicular torsion is typically a clinical diagnosis. Imaging is not routinely indicated but may be considered in patients with atypical clinical features. Because of the significant risk of infertility, diagnostic workup should not delay the management of suspected testicular torsion.

Imaging

Duplex ultrasound of the scrotum ^[6]^[7]^[8]
- Indication: inconclusive clinical findings ^[6]
- Characteristic findings ^[8]
  - Twisting of spermatic cord (whirlpool sign)
  - Reduced or absent blood flow to/from the affected testis
  - Heterogeneous appearance of testicular parenchyma indicates testicular necrosis.
Radionuclide imaging ^[1]^[9]
- Indications
  - Inconclusive clinical findings
  - Evaluate for epididymitis
- Characteristic findings
  - Testicular torsion
    - Areas that do not absorb radionuclide as a result of decreased blood flow to the affected testis (“Cold spots”)
    - Asymmetric blood flow
  - Epididymitis: areas where there is increased radionuclide absorption as a result of increased blood flow in inflammation (“Hot spots”)

Surgical intervention is recommended for suspected testicular torsion, regardless of radiological findings.

Laboratory studies

Not routinely indicated
Urinalysis ^[6]
- Indications: rule out epididymitis
- Findings: leukocytes and erythrocytes in the urine suggest epididymitis but do not exclude torsion (see epididymitis).

Differential diagnoses

Differential diagnosis of scrotal pain
	History	Examination	Lab tests
Testicular torsion	Sudden onset (patients usually present < 24 h from onset of symptoms) Unilateral painful testicle/lower abdomen Nausea or vomiting	Swollen, edematous, tender testicle Abnormal position of testicle (e.g., transverse lie, scrotal elevation) Negative Prehn sign Absent cremasteric reflex	Normal inflammatory markers Normal urinalysis
Epididymitis	Gradual onset (e.g., a few days if acute or weeks if chronic) Painful swelling with possible induration Possible history of urethral discharge Fever, dysuria, urinary frequency	Very tender (difficult examination) Positive Prehn sign Positive cremasteric reflex	Increase in generalized inflammatory markers Possible pyuria during urinalysis
Testicular tumor	Slow progression (e.g., weeks to months) Usually painless mass (however, may feel dull ache or "heavy" sensation in the testicle)	Easy palpation of solid mass Possible manifestations of metastatic disease (e.g., distant lymphadenopathy, chest pain, gastrointestinal symptoms) Possible ipsilateral lower limb swelling (venous engorgement due to obstruction)	Possible increase in serum tumor markers (e.g., alpha fetoprotein, or AFP)
Torsion of testicular appendage (hydatid of Morgagni)	Insidious onset of unilateral scrotal pain Usually boys 3–5 years old	Tender testicle Palapable blue dot often present (blue dot sign)	Typically normal inflammatory markers Typically normal urinalysis

Torsion of testicular appendage (hydatid of Morgagni)

Description: The hydatid of Morgagni (appendix of the testes) is an embryological remnant on the upper pole of the testes or at the epididymis (the remnant of the Müllerian duct). This hydatid of Morgagni has the potential to rotate. The resultant symptoms resemble acute testicular torsion.
Clinical features
- Typically boys 3–5 years old
- Insidious unilateral scrotal tenderness
- "Blue dot sign"
Imaging: doppler ultrasound may show an enlarged testicular appendix and or mild hydrocele with preserved testicular blood flow
Management: A conservative approach with NSAIDs may be considered. However, if in doubt, surgical intervention is required to examine the testes.

References:^[1]^[4]^[10]

The differential diagnoses listed here are not exhaustive.

Treatment

Testicular torsion is a medical emergency and should ideally be treated within 6 hours of the onset of symptoms for the best chance of testicular salvage. Manual detorsion in the ER may be attempted prior to surgery for immediate pain relief, but should not delay transferring the patient to the OR.

Exploratory surgery ^[6]^[1]

Indication: suspected testicular torsion
Timing: ideally, within 6 hours of symptom onset ^[1]
Procedure
- Immediate surgical exploration of the scrotum with reduction (untwisting) and orchidopexy of the affected testis
- Orchidopexy of the contralateral testis is recommended because the risk of testicular torsion on the contralateral side increases with previous or current testicular torsion.
- Orchiectomy if the testis is grossly necrotic or nonviable

Manual detorsion ^[1]

Indication: : may be attempted prior to surgery for immediate pain relief or if surgery is not immediately available
Procedure
- Rotate the testis laterally toward the thigh ; two-thirds of torsions occur toward the midline.
- If lateral rotation does not provide symptom relief, rotate the testis toward the midline; one-third of torsions occur laterally. ^[11]
- Surgery should still be performed in all patients to resolve any possible degree of remaining torsion and to prevent recurrence. ^[6]^[6]

Because of the risk of infertility, surgical exploration of the scrotum is recommended in any patient suspected of having testicular torsion, even if manual detorsion has been attempted.

Acute management checklist

Parenteral analgesics (see acute pain management)
Consider imaging if the diagnosis is unclear.
Consider manual detorsion.
Urgent urology consult for immediate surgical exploration of the scrotal sac

Prognosis

Timely intervention within the recommended time period (6 hours from symptom onset) → restoration to previous condition
Late or absent surgical intervention → ischemia → necrosis of the testicles

References:^[3]^[12]

Imaging

Laboratory studies

Torsion of testicular appendage (hydatid of Morgagni)

Exploratory surgery [6][1]

Manual detorsion [1]

Exploratory surgery ^[6]^[1]

Manual detorsion ^[1]