1146 The Use of Ultrasound Compared to Clinical Examination in the Diagnosis of Complete UCL Tear of the Thumb

Aim To compare sensitivity and specificity of clinical examination and ultrasound scan in diagnosing complete UCL tear of the thumb. Method A retrospective cohort study was undertaken at QEHB Birmingham over a period of 8 years from January 2016 to June 2023. Case notes were analysed for 258 patients with thumb UCL injury. Patients who had a complete UCL tear on intraoperative findings were identified and their notes reviewed to establish the findings of pre-operative clinical examination and ultrasound imaging. Sensitivity, specificity, PPVs, and NPVs were calculated for both. Results 75 patients had surgical exploration. Of these, 54 patients had a complete tear identified and 16 had incomplete tears, with 13 patients excluded due to unclear documentation. A final total of 41 patients with complete tears and 16 patients with incomplete tears were included in the study. 12 of these patients had ultrasound imaging of their UCL. The true positive, false positive, false negative and true negative values for clinical examination and US were 24,3,17,6 and 8,2,2,0 respectively. The sensitivity, specificity, PPV and NPV for clinical examination compared to US were 0.58 vs 0.80, 0.66 vs 1.00, 0.88 vs 0.80, 0.26 vs 0.00 respectively. Conclusions Ultrasound imaging of thumb UCL injuries has a higher sensitivity, specificity and PPV for diagnosis of complete tears compared to clinical examination. Further larger prospective studies are warranted to validate and further refine the role of ultrasound in the diagnostic pathway.