Summary

Testicular torsion is the sudden twisting of the spermatic cord within the scrotum. It most commonly affects children and young men. Because of the risk of ischemia and possible infarction of the testicle, 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 testicle with an absent cremasteric reflex. The diagnosis is confirmed on ultrasound. Testicular torsion (including suspected cases) requires prompt surgical correction within six hours of symptom onset to prevent complications. Important differential diagnoses include orchitis and epididymitis, and 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

Laboratory tests

Urine dipstick to exclude epididymitis
Laboratory control

Ultrasound of the scrotum

Indications:
- Ambiguous clinical findings
- Low suspicion of testicular torsion
Gray-scale ultrasound
- Twisting of spermatic cord
- Initial testicular homogeneity that becomes heterogenous after 24 hours when necrosis occurs
Doppler ultrasound: reduced perfusion in the affected testicle

Surgical intervention is recommended for suspected testicular torsion, regardless of radiological findings!
References:^[1]^[6]^[4]^[7]^[8]^[9]

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 be treated upon suspicion within 6 hours of the onset of symptoms to prevent loss of the testis.
Immediate surgical exploration of the scrotum with reduction (untwisting) and orchidopexy
Orchidopexy of the contralateral side is recommended
Manual detorsion may be attempted to possibly buy time and relieve symptoms, but is not a replacement for surgical exploration

Because of the risk of significant consequences for (often young) patients, surgical exploration of the scrotum is recommended in cases of suspected testicular torsion!

References:^[1]^[6]

Acute management checklist

Parenteral analgesics (see acute pain management)
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]^[6]