EM Cases: Testicular Torsion: A Diagnostic Pathway

Originally published at EM Cases. Reposted with permission. Listen to accompany podcast HERE

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In this Part 2 of Urologic Emergencies EM Cases main episode podcasts Dr. Natalie Wolpert and Dr. Yonah Krakowsky answer questions about testicular torsion including: when, after the onset of symptoms, is the testicle salvageable? How sensitive is the presence of cremasteric reflex in ruling out testicular torsion? Are there any set of clinical symptoms and signs or decision tools (such as the TWIST Score) that can rule in or rule out testicular torsion with confidence? How accurate is doppler ultrasound in the diagnosis of testicular torsion? To what degree does Prehn’s sign help distinguish epididymitis from testicular torsion? How can you distinguish testicular torsion from torsion of testicular appendage? When is manual de-torsion indicated and how effective is it? and many more…

Podcast voice editing by Emma Helman; production, sound design & editing by Anton Helman

Written Summary and blog post by Winny Li, edited by Anton Helman July, 2020.

Cite this podcast as: Helman, A. Krakowsky, Y. Wolpert, N. Testicular Torsion: A Diagnostic Pathway. Emergency Medicine Cases. July, 2020. https://emergencymedicinecases.com/testicular-torsionAccessed [date]

Testicular torsion occurs when the spermatic cord twists leading to impaired blood flow to the testicle, causing ischemia and potentially tissue necrosis. A bell clapper deformity is a predisposing factor in testicular torsion where the tunica vaginalis attaches high on the spermatic cord, leaving the testis free to rotate within the tunica vaginalis.

Time is Testes

Historically, we thought the time window for possible salvage and survival of a torsed testicle is 6-8 hours. However, more recently it has been recognized that survival percentages are significant beyond the commonly held 6 to 8-hour time frame and even after 24 hours. During this time, there may be intermittent torsion detorsion, leading to the variable spectrum of salvageability and difficulty in predicting the precise onset of irreversible ischemia.

Bottom line: Duration of symptoms should not guide management decisions. All cases of suspected testicular torsion must be treated as a surgical emergency, even if the time from onset is beyond 6-8 hours. The sooner the testicle is de-torsed, the more likely salvageability.

Testicular torsion can occur at any age

Testicular torsion can occur at any age, but it is primarily associated with a bimodal distribution in the first year of life and in adolescence. Although exceedingly rare, there are case reports of testicular torsion occurring in men over the age of 40. We should therefore still maintain an index of suspicion for testicular torsion in older men who present with unilateral acute scrotal pain.

Classic Signs and Symptoms of Testicular Torsion

  • Acute unilateral pain
  • Scrotal erythema, edema and swelling
  • Absent cremasteric reflex
  • Position: high, horizontal lie
  • Nausea and vomiting

Acute unilateral pain

Most patients with testicular torsion will present with sudden onset of severe unilateral testicular pain, often radiating to the groin/abdomen/flank. However, there are subsets of patients who will present with gradual onset of pain, minimal or no pain, intermittent pain caused by intermittent torsion/detorsion or resolution of their initial severe pain followed by reduced pain. Up to 20% of patients with testicular torsion will present with isolated lower abdominal pain. All male patients presenting with lower abdominal pain should have a gentile examination for signs of torsion.


Scrotal erythema, edema and testicular swelling are commonly reported in patients with torsion. However, these findings also overlap in patients with epididymitis and torsion of the appendix testis. Swelling is a sensitive but not specific sign.

Absent Cremasteric Reflex

The cremasteric reflex is elicited by lightly stroking the skin of the inner thigh. Normally, this causes the cremaster muscle to contract and elevate the testicle. Studies report varying sensitivities as low as 60%. The presence of a cremasteric reflex does not rule out torsion.

Position of testis

While the presence of an elevated testicle (OR = 58.8) and a horizontal testicular lie increases the likelihood of testicular torsion, it is often difficult to palpate the testicle discretely and determine the position.

Prehn’s Sign

Prehn’s sign is the relief of pain with elevation of the testis commonly seen in patients with epididymitis. It does not reliably distinguish epididymitis from torsion. One cross section study of 120 patients found the Prehn’s sign was present in 91% of patients with torsion and 21% of those with epididymitis.

TWIST (Testicular Workup for Ischemia and Suspected Torsion) Score

Proposed score for assessing testicular torsion in patients < 18 years of age (Barbosa 2013) and (Frohlich 2017)

Finding Points
Testicular swelling 2
Hard testicle 2
Absent cremasteric reflex 1
Nausea or vomiting 1
High-riding testicle 1
  • PPV 100% when 7 points
  • NPV 96% when <5 points

Our experts recommend against using the TWIST score to rule out torsion, however a score of 7 may warrant urgent urology consult with the aim of immediate surgical intervention without doppler ultrasound confirmation. The TWIST score requires further multicenter validation.


Bottom line: “No discriminating features, in either history or examination conclusively differentiate the correct diagnosis when it comes to testicular torsion” (Sidler 1997)

Diagnosis of testicular torsion

In patients where there is a high index of suspicion for torsion, urgent surgical consultation should not be delayed by diagnostic imaging. Our experts recommend parallel expert consultation and ultrasound imaging when feasible.

Scrotal Doppler ultrasound for testicular torsion

Diagnostic characteristics

  • Sensitivity: 88 – 100% (+LR = 8.8-10)
  • Specificity: 90%

Diagnostic findings

  • Enlarged, hyperemic testicle
  • Increased echogenicity
  • “Whirlpool sign” spiral like pattern of the spermatic cord
  • Decreased doppler flow compared to contralateral side

Color Doppler ultrasound is not always accurate and is subject to false negatives. A partially-torsed testicle may exhibit arterial flow but no venous flow, or may show an abnormal high-resistance pattern of arterial flow. When an ultrasound is non-diagnostic, and the clinical presentation remains concerning, urology consultation remains warranted.

Testicular torsion vs. torsion of testicular appendage

Although a relatively rare phenomenon, the appendix testis is responsible for 92% of testicular appendage torsion with the appendix epididymis accounting for the remainder. These appendages have no physiological function. These presentations are often prepubertal, with sudden onset pain (usually more moderate in severity) and located midline in the scrotum.

blue dot sign is considered pathognomonic, although very rarely clinically seen. This is an area less than 3mm with a pale bluish discoloration present on the scrotum at the superior pole caused by the cyanotic appendage beneath the scrotal wall.

Diagnosis can be confirmed by color Doppler ultrasound. Treatment relies on supportive care with analgesia and scrotal support. The appendage autoamputates in roughly one week.


Management of testicular torsion

All patients with suspicion for testicular torsion should have immediate urology consultation for potential operative exploration and repair. Manual detorsion using the open book technique should only be attempted in instances where there is a significant delay to definitive surgical management due to unforeseen circumstances or in remote locations. Manual detorsion has a poor success rate as up to 1/3 of patients will be torsed in the opposite direction that is assumed by the open book technique.

Take Home Points for testicular torsion

  • Consider the diagnosis of testicular torsion in all patients with acute testicular pain irrespective of age
  • Duration of symptoms should not guide urgency of management; all cases of suspected testicular torsion must be treated as a surgical emergency
  • The presence of a cremasteric reflex does not rule out testicular torsion
  • History, physical examination and ultrasound all have significant limitations in making the diagnosis; the gold standard is surgical exploration
  • Torsion of the testicular appendage has similar presentation but only requires supportive care; the diagnosis is confirmed with ultrasound

Bonus top 3 urology pearls from the urologist’s perspective for emergency physicians

  1. For suspected penile fractures (a tear in the tunica albuginea), a penile ultrasound in the ED can optimize surgical outcomes and planning for definitive OR. Fixation is not a surgical emergency.
  2. Unilateral kidney stones rarely cause AKI if the patient has a baseline functional contralateral kidney. IV fluid rehydration will often correct renal function obviating the need for admission to hospital.
  3. A KUB X-ray and urine pH can help guide treatment of kidney stones (monitor passage, help with dissolution and guide if the patient is a candidate for shock wave lithotripsy)

References for testicular torsion



Mellick LB, Sinex JE, Gibson RW, Mears K. A Systematic Review of Testicle Survival Time After a Torsion Event. Pediatr Emerg Care. 2019;35(12):821-825.

Beni-Israel T, Goldman M, Bar Chaim S, Kozer E. Clinical predictors for testicular torsion as seen in the pediatric ED. Am J Emerg Med. 2010;28(7):786-9.

Mellick LB. Torsion of the testicle: it is time to stop tossing the dice. Pediatr Emerg Care. 2012;28(1):80-6.

Perrotti M, Badger W, Prader S, et al. Medical malpractice in urology, 1985 to 2004: 469 consecutive cases closed with indemnity payment. J Urol. 2006;176(5):2154Y2157.

Mejdoub I, Fourati M, Rekik S, Rebai N, Hadjslimen M, Mhiri MN. Testicular torsion in older men: It must always be considered. Urol Case Rep. 2018; 21:1-2.

Ciftci AO, Senocak ME, Tanyel FC, et al. Clinical predictors for differential diagnosis of acute scrotum. Eur J Pediatr Surg. 2004;14(5):333Y338.

Paul EM, Alvayay C, Palmer LS. How useful is the cremasteric reflex in diagnosing testicular torsion? [Supplement]. J Am Coll Surg. 2004;199(3):101.

Sidler D et al. A 25-year review of the acute scrotum in children. S Afr Med J. 1997;87(12) 1696-8.

Frohlich LC, et al. Prospective validation of clinical score for males presenting with an acute scrotum. AEM Dec 2017.

Bandarkar AN, Blask AR. Testicular torsion with preserved flow: key sonographic features and value-added approach to diagnosis. Pediatr Radiol. 2018;48(5):735-744.

Mcdowall J, Adam A, Gerber L, et al. The ultrasonographic “whirlpool sign” in testicular torsion: valuable tool or waste of valuable time? A systematic review and meta-analysis. Emerg Radiol. 2018;25(3):281-292.

Eaton SH, Cendron MA, Estrada CR, et al. Intermittent testicular torsion: diagnostic features and management outcomes. J Urol 2005;174(4 Pt 2):1532–5.

Barbosa, JA, et al. Development of initial validation of a scoring system to diagnose testicular torsion in children. The Journal of Urology. 2013; 189:1853-8

Prospective Validation of Clinical Score for Males Presenting with an Acute Scrotum. Acad Emerg Med. 2017 Dec;24(12):1474-1482.


Other FOAMed resources on testicular torsion

EMdocs testicular torsion pearls and pitfalls


Pediatric EM Morsels on TWIST Score

Core EM on testicular torsion

Drs. Helman, Wolpert and Krakowsky have no conflicts of interest to declare

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