External validation of the “deformity, edema, and pain in pronation” model for predicting wrist fractures

BACKGROUND:The aim of this study is to externally validate the "Deformity, Edema, and Pain in Pronation" model, which determines the necessity for radiography in patients with wrist trauma. METHODS:This prospective, cross-sectional study was performed in a tertiary emergency department (ED). All patients admitted to the ED with wrist trauma aged 18 years and older were included in the study. Patients who did not have acute and blunt wrist trauma, those who could not be fully examined due to various reasons, and patients who did not wish to participate were excluded. Each patient was examined by their responsible physician, and imaging tests were requested based on the indications. All radiographic images were evaluated by an orthopedic surgeon who was blinded to the clinical information. This evaluation was accepted as the standard reference for diagnosing fractures. RESULTS:391 patients were included in the study. 170 patients (43.5%) had at least one fracture. The sensitivity and specificity of the model formed in our study in predicting wrist fractures were 98.77% (95% CI: 95.61-99.85) and 27.60% (95% CI 21.82-34.00), respectively. The area under the receiver operating characteristic curve (AUC) on external validation of the model was 0.878 (p < 0.001; 95% CI: 0.844-0.913). With the practice of this rule, there would be a 16% decrease in X-ray imaging request, while only 0.5% patients would have missed inoperable fractures. CONCLUSION:The "deformity, edema, and pain in pronation" model is a reliable and practical clinical decision rule for determining the necessity of radiography in wrist trauma.