Evaluation of the Diagnostic Performance of the Testicular Workup for Ischemia and Suspected Torsion (TWIST) Score for Assessing the Risk of Testicular Torsion in Adult Patients Presenting to the Emergency Department With Scrotal Pain - A Prospective Observational Study

Evaluation of the Diagnostic Performance of the Testicular Workup for Ischemia and Suspected Torsion (TWIST) Score for Assessing the Risk of Testicular Torsion in Adult Patients Presenting to the Emergency Department With Scrotal Pain

This prospective multicenter observational study aims to evaluate the diagnostic accuracy of the Testicular Workup for Ischemia and Suspected Torsion (TWIST) score in adult patients presenting with acute scrotal pain in Swedish Emergency Departments.

The TWIST score is a clinical decision tool originally validated in pediatric populations to stratify patients into low, intermediate, and high risk for testicular torsion. The study will include men aged 18-40 years presenting with scrotal pain or symptoms suggestive of torsion. Patients with scrotal trauma, symptom duration over one week, previous testicular surgery, or inability to give informed consent in Swedish will be excluded.

Participants' clinical findings will be recorded on a standardized form, and the TWIST score will be calculated. Management will follow standard clinical practice independently of the study. Primary outcome is the diagnostic accuracy of the TWIST score to rule out testicular torsion in low-risk patients (TWIST 0-2). Secondary outcomes include diagnosis of torsion within 30 days, time to surgery, patient-reported pain, number of Doppler ultrasounds performed, and the potential reduction in unnecessary imaging.

The study will be conducted at multiple Swedish sites, including Linköping University Hospital, under oversight by the Swedish Ethical Review Authority (Etikprövningsmyndigheten, decision number 2025-07400-01). The results aim to inform clinical practice by providing a validated decision-support tool for adult patients with suspected testicular torsion, potentially improving patient outcomes and resource utilization.

Study Overview

• Status: Recruiting
• Conditions: Acute Scrotum; Testicular Torsion; Scrotal Pain

Detailed Description

Acute scrotal pain is a common presentation in Emergency Departments, but the diagnosis of testicular torsion (TT) is relatively rare. Prompt identification is crucial because TT requires urgent surgical intervention to preserve testicular viability. Delays in diagnosis, particularly due to unnecessary imaging or non-standardized clinical assessment, may result in testicular loss.

The TWIST (Testicular Workup for Ischemia and Suspected Torsion) score is a clinical decision tool developed and validated in pediatric populations to stratify risk of TT based on five clinical features: testicular swelling, hard testis, high-riding testis, absent cremasteric reflex, and nausea/vomiting. Adult validation is limited, and no large-scale multicenter study has evaluated its performance in adult Emergency Department settings in Sweden.

This study will prospectively collect structured clinical data from adult patients aged 18-40 years presenting with scrotal pain at participating Swedish EDs. The TWIST score will be calculated from documented clinical findings. The study does not influence clinical management; patients will receive standard care, including imaging or surgical intervention as deemed appropriate by treating clinicians.

Primary objectives focus on the diagnostic accuracy of TWIST for ruling out TT in low-risk patients, while secondary objectives include assessment of the score in identifying high-risk patients, measurement of time to surgery, evaluation of pain scores, and analysis of imaging utilization. Data will also be linked to the Swedish Perioperative Register (SPOR) for outcomes such as surgery performed, complications, and final diagnoses.

The study is designed to evaluate whether structured use of TWIST can support evidence-based, standardized risk stratification in adults, potentially improving patient outcomes, streamlining resource use, and reducing unnecessary delays in diagnosis and treatment. Ethical oversight is provided by the Swedish Ethical Review Authority (Etikprövningsmyndigheten, decision 2025-07400-01).

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

• Study Contact: Name: Jens Wretborn, MD, PhD; Phone Number: +461030000; Email: jens.wretborn@liu.se

Study Locations

• Sweden
  • Östergötland County
    • Linköping, Östergötland County, Sweden, 58185
      • Recruiting
      • Linköping University Hospital, ED
      • Contact: Jens Ragnar Wretborn, MD, PhD; Phone Number: +46; Email: jens.wretborn@liu.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult men aged 18-40 years presenting to participating Emergency Departments in Sweden with acute scrotal pain or scrotal symptoms suggestive of testicular torsion. Patients with trauma-related scrotal pain, symptom duration longer than one week, previous testicular surgery, or inability to provide informed consent are excluded. The study aims to evaluate the diagnostic accuracy of the TWIST score in a real-world adult ED population.

Description

Inclusion Criteria:

• Male patients aged 18-40 years

Presenting to the Emergency Department with acute scrotal pain or scrotal symptoms

Suspicion of testicular torsion before clinical assessment

Exclusion Criteria:

• Scrotal pain or symptoms caused by trauma

Symptom duration > 1 week

History of testicular surgery

Inability to provide informed consent (e.g., language barrier or cognitive limitation)

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Adult ED Patients with Acute Scrotal Pain; All participants are assessed according to routine clinical care in the Emergency Department. The TWIST score is calculated from standard clinical findings but does not influence management; decisions regarding imaging or surgery follow usual clinical practice. Data on symptoms, TWIST score components, and outcomes (including surgical confirmation of testicular torsion) are collected prospectively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic Accuracy of the TWIST Score (Low-Risk Group)	Number and proportion of adult patients with a low-risk TWIST score (0-2) who are confirmed not to have testicular torsion based on surgical exploration or follow-up within 30 days. This measures the sensitivity of the TWIST score to safely rule out torsion.	Up to 30 days from ED visit

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to exploration	Time in hours from patient arrival in the Emergency Department to surgical intervention for suspected testicular torsion.	30 days from ED visit
Testicular torsion	Number of testicular torsions found up to 30 days from ED visit	30 days from inclusion
Pain at study inclusion	Pain at inclusion to the study measured by NRS	Up to one hour from inclusion in the study.
Use of Ultrasound	If ultrasound was used during the Emergency Department visit	Up to 48 hours from inclusion or ED discharge, whichever comes first

Collaborators and Investigators

• Sponsor: University Hospital, Linkoeping
• Collaborators: Linkoeping University
• Investigators: Principal Investigator: Jens Wretborn, MD, PhD, Linkoeping University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2026
• Primary Completion (Estimated): January 31, 2028
• Study Completion (Estimated): December 31, 2029

Study Registration Dates

• First Submitted: March 6, 2026
• First Submitted That Met QC Criteria: March 24, 2026
• First Posted (Actual): March 27, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 23, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Testicular Torsion; Acute Scrotum; Testicular Workup for Ischemia and Suspected Torsion (TWIST)
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Diseases, Male; Male Urogenital Diseases; Spermatic Cord Torsion
• Other Study ID Numbers: 2025-07400-01 (Other Identifier: Swedish Ethical Review Authority approval number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The study will collect sensitive health data from adult patients with acute scrotal pain. Due to patient privacy and data protection regulations, individual participant-level data will not be shared outside the research team.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No