Diagnosing with a TWIST: Systematic Review and Meta-Analysis of a Testicular Torsion Risk Score

Abstract

Purpose:The Testicular Workup for Ischemia and Suspected Torsion (TWIST) score is a 7-point tool to evaluate acute scrotal pain. Parameters include testicular swelling (2 points), hard testis (2), high-riding testis (1), absent cremasteric reflex (1) and nausea/vomiting (1). This review aimed to determine the diagnostic utility of TWIST and its role in risk stratification.Materials and Methods:A systematic review and meta-analysis of diagnostic test accuracy was conducted. Five risk stratification systems were explored, including the Barbosa (0–2, 3–4, 5–7) and Sheth (0, 1–5, 6–7) scoring systems, to obtain sensitivity, specificity and area under the receiver operating curve.Results:Thirteen studies were identified, 9 prospective studies proceeded to meta-analysis of diagnostic test accuracy and 5 pediatric studies (1,060 patients, 199 torsions) were included in the primary analysis. The most accurate risk stratification system was Barbosa (0–2, 3–4, 5–7), with an AUC of 0.924 (95% CI: 0.865, 0.956). Barbosa showed favorable sensitivity in low-risk patients (0.984), facilitating rule out of torsion, and favorable specificity (0.975) in high-risk patients, facilitating urgent surgical exploration. Sensitivity and specificity in intermediate-risk patients were 0.922 and 0.682, respectively, indicating a need for further workup with ultrasound. Using this stratification, 65.2% of patients were low-risk, 19.9% were intermediate-risk and 14.9% were high-risk. Per 100 presentations of acute scrotum, there was a missed torsion rate of 1.6/100, ultrasound rate of 19.9/100 and negative exploration rate of 2.5/100.Conclusions:TWIST is an effective tool for suspected testicular torsion and is appropriate for widespread adoption. The Barbosa scoring system is reliable and reduces reliance on scrotal ultrasound.

Is There a Relationship Between Waking Up from Sleep and the Onset of Testicular Torsion?

“… 66 A recent systematic review and meta-analysis showed that TWIST is a valuable technique for detecting possible TT and is suitable for widespread use, suggesting that it is a helpful tool for making treatment decisions in cases of acute scrotal presentation. 67 Based on our review, we suggested adding one more point to the TWIST score for TT presentation concomitant with sleep. Adopting this upgrade in the TWIST score to confirm the association of sleep as a risk factor for TT requires further investigation through future studies.…”

This Month in Pediatric Urology

“…Qin and Qu (page 62) from Australia performed a systematic review and meta-analysis looking at the efficacy of the scores in predicting torsion. 4 Different stratification systems (Barbosa, Sheth and 3 other schemes that group the scores into risk tiers) were compared. They concluded that the original system by Barbosa remains the most reliable but note that there is still room for improvement by increasing the specificity of the intermediate risk group.…”

Testicular Torsion

“…Those with a TWIST score of 0–2 are of low risk for TT, a score of 3–4 indicates intermediate risk, and a score of 5–7 points indicates a high risk for TT (Frohlich et al, 2017). Many studies have validated the use of the TWIST score (Barbosa et al, 2014; Frohlich et al, 2017; Qin & Qu, 2022).…”