Testicular torsion is a true urologic emergency and must be differentiated from other complaints of testicular pain because a delay in diagnosis and management can lead to loss of the testicle. [1] Testicular torsion accounts for as many as 26% of cases of acute scrotum. [2] Although testicular torsion can occur at any age, including the prenatal and perinatal periods, it most commonly occurs in adolescent males; it is the most frequent cause of testicle loss in that population. [3, 4, 5, 6]

In pediatric patients, the following features are associated with higher likelihood of torsion [7] :

Pain duration of less than 24 hours

Nausea or vomiting

High position of the testicle

Transverse lie of the affected testis

Abnormal cremasteric reflex

Embarrassment in the prepubescent or pubertal patient may prevent disclosure of scrotal pain, and scrotal pain referred to the lower abdomen may be perceived by the adolescent patient as not being of scrotal or testicular origin. For this reason, any adolescent boy who complains of lower abdominal pain should undergo examination of the external genitalia to rule out the possibility of scrotal or testicular pathology. [8]

A retrospecitive review of 73 adolescent patients (median age, 15.3 yr) who underwent surgical treatment for testicular torsion reported that patients who presented with abdominal pain, compared to patients with initial testicular pain, had a significant delay in diagnosis/treatment (median pain duration of 36 hr vs 5 hr) and a significantly higher rate of testicular loss (81% vs 4%). [9] Study results suggest that every 10 minutes of delay in the ED may increase the chance of having a nonviable testis in exploration by 4.8%. [5]

Testicular torsion is a clinical diagnosis. If the history and physical examination strongly suggest testicular torsion and detorsion procedures do not work, the patient should undergo surgery without any delays to perform imaging studies. When there is a low suspicion of testicular torsion, color Doppler and power Doppler ultrasonography can be used to demonstrate arterial blood flow to the testicle while providing information about scrotal anatomy and other testicular disorders. The whirlpool sign—a spiral-like pattern seen on assessment of the spermatic cord using standard high-resolution ultrasonography and/or color Doppler sonography—is a definitive sign for testicular torsion in pediatric and adult patients, but it has a limited role in neonates. Some studies suggest that MRI, particularly with contrast enhancement, is highly accurate for testicular torsion, particularly when torsion knot or whirlpool patterns are evident. [10, 3, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]

According to American College of Cardiology (ACR) Appropriateness Criteria, quick and accurate diagnosis of acute scrotum and its etiology with imaging is necessary because a delayed diagnosis of torsion for as little as 6 hours can cause irreparable testicular damage. According to the ACR, ultrasound duplex Doppler ultrasonography of the scrotum is usually appropriate as the initial imaging modality for the acute onset of scrotal pain without trauma or antecedent mass in an adult or child. Reported sensitivity of color Doppler US in detecting torsion ranges from 96% to 100%, with a specificity of 84% to 95%. The use of a combination of dynamic contrast-enhanced T1-weighted MRI with T2-weighted and T2*-weighted sequences may help distinguish patients with torsion alone from those with torsion and hemorrhagic necrosis. [25, 18, 19, 26, 27, 28]

A Doppler sonogram of an avascular testicle is shown below. Surgical exploration should not be delayed for the sake of performing imaging studies.

Transverse power Doppler image of both testes illustrates an enlarged, avascular left testicle. View Media Gallery

If the diagnosis of torsion is suspected on clinical grounds, early urologic consultation is mandatory because definitive treatment is surgery for detorsion and orchiopexy or possible orchiectomy. Transfer the patient if no urologist is available. Administer analgesic medication, as testicular torsion is typically very painful.

The TWIST (Testicular Workup for Ischemia and Suspected Torsion) scoring system was developed to determine the risk of testicular torsion on clinical grounds and thereby decreasing the need for ultrasonography. [29, 30] Patients are classified as low, intermediate, or high risk.

TWIST consists of the following measures:

Testis swelling (2 points)

Hard testis (2)

Absent cremasteric reflex (1)

Nausea/vomiting (1)

High-riding testis (1)

The TWIST score is based on the sum, ranging from 0 to 7. The risk stratifying scores for those at low risk for testicular torsion are 0 to 2 points; intermediate risk, 3 to 4 points; and high risk, 5 to 7 points

The window for possible salvage and survival of a torsed testicle is commonly thought to be 6-8 hours, but testicular survival is known to occur outside that critical window. A systematic review of 2116 cases regarding testis survivability and duration of torsion showed that when operated on within 0 to 6 hours of torsion, 97.2% of testes survived, whereas only 24.4% of testes survived after 25 to 48 hours of torsion. Testicular survival after prolonged torsion may suggest that testicular blood flow was not fully constricted or that intermittent torsion occurred. [4, 23]

Boettcher et al studied 138 patients and determined that pain lasting less than 24 hours, the presence of nausea and/or vomiting, and a high position of the testis upon examination were associated with an increased likelihood of testicular torsion. All patients with 2 or more of these findings had testicular torsion at exploration, with 0% false-positive results. They proposed that a clinical score might help avoid unnecessary scrotal exploration and suggested the use of a clinical score in conjunction with ultrasonography in the assessment and management of boys with acute scrotal pain. [31]

For other discussions of this condition, see the Medscape Reference articles Testicular Torsion and Pediatric Testicular Torsion.