Testicular torsion

Pathogenesis and clinical presentation

In adolescents, the condition typically develops within the tunica vaginalis. Normally, it securely anchors the organ to the posterior wall of the scrotum. In a developmental anomaly known as the bell-clapper deformity (bell clapper deformity), this fixation is absent or inadequate. The testis hangs freely and can rotate around its axis.

Clinically, establishing a precise diagnosis is difficult: standard physical examination distinguishes torsion from other causes of acute scrotum in only half of the cases.

Classic triad:

• Pubertal boy or infant.
• Sudden acute scrotal pain (though painless presentations have also been described).
• Vomiting in the absence of fever.

Time factor and prognosis

Torsion is an absolute surgical emergency (surgical emergency). The prognosis for testicular salvage directly depends on the time elapsed before diagnosis. Therefore, the risk of unnecessary surgical exploration is fully justified by the chance of saving the testicle.

Time-based classification:

1. Acute: from 24 hours to 10 days.
2. Subacute and chronic: subsequent stages.
3. Missed torsion (missed torsion): duration exceeding 24 hours.

Organ salvage rate:

• Within the first 6 hours — 80%.
• With surgical delay exceeding 24 hours — drops to 20%.

Ultrasound examination (US)

Ultrasound is the primary imaging modality, but in younger children, Doppler evaluation can be limited. Even modern transducers sometimes fail to detect extremely slow physiological blood flow in small testicles.

• Grey-scale US: In the acute phase, ipsilateral increased echogenicity, an enlarged heterogeneous testicle and epididymis, scrotal edema, and a reactive hydrocele are noted. These signs are nonspecific. Rule of thumb: an edematous hypoechoic testicle is usually nonviable; one that appears normal on standard ultrasound can often be salvaged.
• Color Doppler flow imaging (CDFI): Significantly improves diagnostics. Spectral analysis of the arteries and comparison with the healthy side are mandatory. Any asymmetry is suspicious for partial or intermittent torsion.
• CEUS (Contrast-enhanced ultrasound): Useful in emergency settings.

Specific patterns:

• Whirlpool sign (whirlpool sign): visualization of the twisted spermatic cord (sensitivity 92%, specificity 99%).
• Corkscrew-like appearance (corkscrew-like appearance): direct evidence of torsion when tracing vessels into the inguinal canal.

Critical note: The presence of normal blood flow does not completely rule out the diagnosis!

Differential diagnosis

During ultrasound, it is important to differentiate torsion from other common causes of acute scrotal pain and swelling:

• Epididymitis or orchitis: blood flow in the organ is normal or even increased.
• Torsion of testicular appendages (torsion of testicular appendages): the most common cause of acute pain in children. The testicle itself appears normal, but an enlarged appendage and fluid are visible. Often presents a misleading picture of inflammatory changes without a characteristic nodule.
• Acute scrotal edema: sudden onset of a painful, hyperemic sac with a completely normal ultrasound appearance of the underlying structures.

Class and exam questions

What else to study on this topic

• Torsion of testicular appendages (hydatids) and its ultrasound appearance
• Epididymitis and orchitis: differential diagnosis
• Acute scrotal edema in children
• The role of contrast-enhanced ultrasound (CEUS) in emergency diagnostics
• Testicular microlithiasis and its association with previous torsion

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.