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Evidence Based Strategies for Common Clinical Questions

July 2022

The Answer Might Be Below the Belt: How to Avoid Missing Testicular Torsion


Author: Kristin Palmen, MD | Pediatric Resident


Column Editor: Kathleen Berg, MD | Co-Director, Department of Evidence Based Practice | Pediatric Hospitalist, Division of Pediatric Hospital Medicine | Associate Professor of Pediatrics, UMKC School of Medicine 


The implications of missing testicular torsion are significant and include impaired testicular function and infertility. Testicular torsion occurs when the blood supply to the testicle is reduced due to twisting of the spermatic cord. The severity of ischemia depends on the duration of the torsion, making prompt diagnosis essential. Details on initial history and physical presentation can help identify testicular torsion before it is too late.  
Testicular torsion has a bi-modal age distribution with one peak in the neonatal period and a second peak around puberty. Testicular torsion accounts for about 10%-15% of acute scrotal disease in children.1 In general, testicular torsion occurs without any precipitating event; however, genetic factors, environmental factors, preceding trauma, and anatomical variants including the bell clapper deformity may be predisposing factors.2 The bell clapper deformity is an abnormal fixation of the tunica vaginalis present in about 12% of males.2 Normally, the tunica vaginalis is attached directly to the posterolateral part of the testis. When fixed more superiorly, the tunica vaginalis surrounds the epididymis, distal spermatic cord and testis, leading to more mobility of the testis and a higher risk of twisting at the level of the spermatic cord.1  
Most commonly, torsion presents with severe, acute, unilateral testicular pain. Pain may radiate to the lower abdomen and groin and is often accompanied by nausea and vomiting. Exam reveals a unilateral high riding and swollen testis with diffuse tenderness on palpation.3 Additionally, the cremasteric reflex will be absent. This reflex is less useful in very young boys because studies have shown the cremasteric reflex is only present in 50% of boys less than 30 months old.4 However, the loss of the cremasteric reflex is at least 99% sensitive for testicular torsion, meaning that its presence makes torsion exceedingly unlikely.2 While uncommon, an undescended testicle can also torse, causing a tender, swollen inguinal mass and/or abdominal pain. Therefore, every male with abdominal or inguinal pain requires a genital exam. 
If there is suspicion for torsion, the Testicular Workup for Ischemia and Suspected Torsion (TWIST) score is a useful clinical decision tool that can help direct next steps of diagnosis and management. It is a score ranging from 0 to 7 based on presence of testicular swelling (2 points), hard testicle (2 points), absent cremasteric reflex (1 point), nausea/vomiting (1 point) and high-riding testicle (1 point). Barbosa et al. found this score to have negative and positive predictive values of 100% for cutoffs of 2 and 5 respectively, with specificity of 81% and sensitivity of 75%.5 A score of 0 to 2 is low risk, so ultrasonography is not required, and other diagnoses should be considered. A score of 3 to 4 is intermediate risk and an ultrasound with Doppler should be obtained. A high-risk score of 5 or greater requires an urgent urologic consult with immediate surgical investigation.6 The TWIST score was validated in subsequent pediatrics studies in 2016 and 2022, both confirming its high positive and negative predictive values.6,7   
Surgical management involves the surgeon assessing the viability of the testis after opening the scrotal sac. If the testis is necrotic, an orchiectomy is performed. If it is viable, then the surgeon will de-torse it and orchiopexy is performed for the contralateral testicle and the salvaged testicle. These procedures are standard of care, since the anatomic defect that allowed the testicular torsion to occur is most likely bilateral.3  
There is a four- to eight-hour window before significant ischemic damage occurs. If surgery is performed within six hours of symptom onset, reported testicular salvage rates are 90%-100%. Testicular salvage rates decrease to 50% if symptoms are present for more than 12 hours, and less than 10% if symptoms are present for 24 hours or more. Overall salvage rates are reported to be 62%-85% in descended testes and 29%-40% in undescended testes.8 Even if blood flow is restored, there can be long-term adverse outcomes including defects in spermatogenesis and decreased fertility.2 To ensure that testicular torsion is diagnosed quickly and correctly, always remember to perform a genital exam for boys presenting with groin, abdominal or inguinal pain, or for unexplained nausea/vomiting. Use the TWIST score and refer for surgery immediately if torsion is suspected.  



  1. Sharp VJ, Kieran K, Arlen AM. Testicular torsion: diagnosis, evaluation, and management. Am Fam Physician. 2013;88(12):835-840.
  2. Laher A Ragavan S, Mehta P, Adam A. Testicular torsion in the emergency room: a review of detection and management strategies. Open Access Emerg Med. 2020;12:237-246. doi:10.2147/OAEM.S236767
  3. Testicular torsion. ClinicalKey. April 14, 2021. Accessed March 20, 2022. 
  4. Caesar RE, Kaplan GW. The incidence of the cremasteric reflex in normal boys. J Urol. 1994;152(2 Pt 2):779-780. doi:10.1016/s0022-5347(17)32707-6
  5. Barbosa JA, Tiseo BC, Barayan GA, et al. Development and initial validation of a scoring system to diagnose testicular torsion in children [published correction appears in J Urol. 2014 Aug;192(2):619]. J Urol. 2013;189(5):1859-1864. doi:10.1016/j.juro.2012.10.056
  6. Pan P. Validation of the Testicular Workup for Ischemia and Suspected Torsion (TWIST) score in the diagnosis of testicular torsion in children with acute scrotum. Indian Pediatr. 2020;57(10):926-928.
  7. Sheth KR, Keays M, Grimsby GM, et al. Diagnosing testicular torsion before urological consultation and imaging: validation of the TWIST score. J Urol. 2016;195(6):1870-1876. doi:10.1016/j.juro.2016.01.101
  8. Kumar V, Matai P, Prabhu SP, Sundeep PT. Testicular loss in children due to incorrect early diagnosis of torsion. Clin Pediatr (Phila). 2020;59(4-5):436-438. doi:10.1177/0009922820903037