Validation of the TWIST score for testicular torsion in adults

Purpose: The TWIST (Testicular Work-up for Ischemia and Suspected Torsion) score was developed to allow for expedited diagnosis of testicular torsion (TT) in children based on clinical variables: edema (2 points), hard mass (2), absent cremasteric reflex (1), high-riding testis (1) and nausea/vomiting (1). We sought to validate the TWIST Score applied by non-expert physicians for the diagnosis of testicular torsion in an adult population.

Methods: We prospectively analyzed all consecutive males presenting to a tertiary hospital with acute scrotum. Patients with previous scrotal pathology or trauma were excluded. Physical examination was performed by a general surgeon and variables of TWIST were recorded. All patients underwent Scrotal Doppler Ultrasound. Measures of accuracy of the TWIST score and ROC curves were generated to evaluate its performance in diagnosing TT in adults.

Results: Of 68 patients, 34 had TT (50%). Median age was 24.9 years. According to the original cutoffs of TWIST, 23 patients had a score ≤ 2 among which none had TT. Fifteen patients had a score of 3-4, among which seven had TT. Thirty patients had a score ≥ 5, among which 27 had TT. All 18 patients with a score of 6 or greater had TT (100% PPV). ROC curve revealed an AUC of 0.95.

Conclusion: The TWIST Score is valid for the diagnosis of Testicular Torsion in adults, presenting a PPV of 90% for a cutoff of 5 points and 100% for six points. In all patients with a score of 2 or less, the disease could be safely excluded (100% NPV).

Keywords: Acute scrotum; Emergency medicine; Score; Testicular torsion.