Testicular Torsion
Definition
Testicular torsion refers to the twisting of the spermatic cord, causing compromised blood supply to the testis
Aetiology
Most cases occur spontaneously, but trauma / vigorous activity can precipitate torsion [Ref]
Key risk factors: [Ref]
- Congenital
- Bell-clapper deformity – most significant (present in up to 12% of males and is often bilateral)
- An anatomical variant where the testis is not properly attached to the tunica vaginalis
- The testis is therefore free to rotate, like the clapper of a bell swinging inside a bell
- Cryptorchidism (undescended testes)
- Bell-clapper deformity – most significant (present in up to 12% of males and is often bilateral)
- Bimodal age distribution
- Neonatal period (first 30 days of life)
- Adolescence (12-18 y/o)
- Previous episodes of intermittent torsion
Clinical Features
Symptoms
Typically presents as a sudden onset of severe unilateral scrotal pain [Ref]
- The pain might radiate to the lower abdomen / inguinal region
- Often with nausea and vomiting
Torsion in neonates: [Ref]
- Common for there to be an absence of pain (i.e., tenderness or irritability in neonates) & systemic symptoms (e.g., nausea & vomiting).
- Torsion is mainly identified through examination and typically presents as a firm, enlarged, and often discoloured scrotal mass.
- Testis may also appear atrophied or absent (in severe atrophy) if torsion is longer-standing (e.g., occurring prenatally or perinatally).
Signs
Typical examination findings: [Ref]
- Severe diffuse tenderness
- Scrotal skin may be indurated, erythematous, and warm
- Testicular position
- High-riding testis (the affected testis appears elevated as the twisting shortens the cord, pulling the testis upward)
- Horizontal lie (the affected testis lies sideways rather than vertically, as the torsion causes the testis to rotate)
- Absent cremasteric reflex on the affected side (highly specific finding for torsion) (due to impaired function of the cremasteric muscle)
The cremasteric reflex is regulated by the cremaster muscle (stimulus: stroking the medial thigh, response: elevation of the testis via cremaster muscle contraction):
- Sensory input: ilioinguinal nerve (L1)
- Motor output: genital branch of genitofemoral nerve (L1-L2)
In testicular torsion, twisting of the spermatic cord impairs the motor output of the reflex → cremasteric muscle cannot contract → absent reflex
Prehn’s sign (whether pain improves when the testis is elevated) is not a reliable test for torsion, but a negative Prehn’s sign (no pain relief on testis elevation) makes epididymo-orchitis less likely, and therefore raises suspicion for torsion.
Complications
The key complication is testicular infarction and necrosis (→ impaired spermatogenesis and subfertility / infertility) [Ref]
- This can occur 4-8 hours after symptom onset
Testicular atrophy can occur, even after successful detorsion
Investigation and Diagnosis
Testicular torsion is a clinical diagnosis
If clinical history and examination strongly suggest testicular torsion → refer for urgent urological consultation and surgical exploration (without delaying for further investigations) [Ref]
Imaging
If there is doubt in the diagnosis, 1st line imaging is Doppler ultrasound of the scrotum [Ref]
- ↓ / Absent Doppler flow is a key diagnostic feature
- The Whirlpool sign indicates a twisted spermatic cord
- Other features
- Enlarged (oedematous) testes
- Heterogeneous (vs homogenous) testicular parenchyma → indicative of areas of necrosis
Laboratory Tests
Laboratory tests are not routinely indicated – they may help rule out alternative diagnoses such as epididymitis
- ↑ Inflammatory markers and a urinalysis suggestive of UTI (e.g. +ve leukocytes, nitrites ± haematuria) favour epididymitis, but do not exclude testicular torsion.
Management
Top priority: immediate surgical exploration → detorsion → assess viability [Ref]
- Viable testis → bilateral orchidopexy
- Grossly necrotic / non-viable testis → orchidectomy + contralateral orchidopexy
Orchidopexy and orchidectomy sound similar, don’t mix them up:
- Orchidopexy (fixing the testis in place): involves suturing the testis to the scrotal wall to prevent further torsion
- Orchidectomy: surgical removal of the testis
Differential: Torsion of Testicular Appendage
Torsion of testicular appendage (hydatid of Morgagni): torsion of the appendix epididymis or appendix testis (instead of the spermatic cord)
It is a differential for testicular torsion and is suggested by: [Ref]
| Feature | Testicular torsion | Torsion of testicular appendage |
|---|---|---|
| Typical age | Adolescents (12-18 y/o) | Children (7–12 y/o) |
| Pain onset | Sudden onset | Gradual or subacute |
| Pain severity | Severe, often unbearable | Mild–moderate |
| Testicular tenderness | Diffuse (whole testis) | Localised to the upper pole |
| Systemic symptoms | Nausea and vomiting are common | Usually absent |
| Testicular lie | High-riding, horizontal lie | Normal testicular lie, vertical lie |
| Cremasteric reflex | Absent | Present |
| Blue dot sign | Absent | Classic feature |
| Doppler US | ↓ / Absent blood flow +/- Whirlpool sign | Normal testicular flow (US may show an enlarged testicular appendage and/or mild hydrocele) |
| Management | Urological emergency
Immediate surgical exploration within 6 hours (do not delay for imaging if high suspicion) |
Conservative management: NSAIDs, rest, reassurance
Unless there are severe symptoms and/or diagnostic doubt in which case surgical exploration is done. |