Distal radioulnar joint stability and ulnar styloid bone marrow oedema: the added value of MRI in triangular fibrocartilage complex injuries

OBJECTIVES: To investigate the diagnostic value of MRI combined with distal radioulnar joint (DRUJ) stability characteristics and ulnar styloid bone marrow oedema (BMO) in differentiating peripheral vs. central triangular fibrocartilage complex (TFCC) injuries, and to establish a multiparametric MRI diagnostic model to optimize preoperative classification accuracy. METHODS: A retrospective analysis of 76 patients with arthroscopically confirmed TFCC injuries (55 peripheral tears, 21 central tears) was conducted. Preoperative MRI evaluated DRUJ stability and BMO. Chi-square tests analysed intergroup differences, binary logistic regression identified predictors, diagnostic efficacy metrics were calculated, and MRI-based classification, DRUJ stability, BMO, and combined models were compared using arthroscopy as the gold standard. RESULTS: The peripheral tear group exhibited significantly higher BMO positivity (82.9% vs. 11.1%) and DRUJ instability rates (70.9% vs. 9.5%) compared to the central tear group (both P < .001). Logistic regression identified BMO positivity (OR = 0.140, 95% CI: 0.044-0.444) and DRUJ instability (OR = 0.103, 95% CI: 0.013-0.428) as independent predictors of peripheral tears (P = .001). The combined model (MRI + DRUJ + BMO) demonstrated superior diagnostic performance (AUC = 0.898, 95% CI: 0.818-0.978; sensitivity = 76.2%, specificity = 94.6%) compared to MRI alone (AUC = 0.810) or DRUJ + BMO models (AUC = 0.822). CONCLUSIONS: The combined model integrating anatomic stability improves diagnostic specificity, providing critical guidance for preoperative stratification, surgical planning, and personalized treatment. ADVANCES IN KNOWLEDGE: BMO and DRUJ stability hold potential as supplementary MRI imaging biomarkers for TFCC injuries classification.