The severity of distal biceps tendon (DBT) injuries ranges from partial to complete tears leading to various clinical manifestation. Accuracy of early diagnosis and selection of treatment are critical to long-term recovery outcomes. Magnetic resonance imaging (MRI) or ultrasonography (US) are two commonly modalities for pre-operative diagnosis. The objective of this study was to determine the efficiency of MRI and ultrasonography US in the diagnosis of DBT rupture confirmed by operative findings.

MRI and US are equally effective in terms of accuracy, sensitivity and specificity.

A total of 31 patients with DBT avulsion and surgical treatment were recruited for this retrospective study. All these patients received both US and MRI examinations prior to surgery. DBT avulsion was classified into partial tear and complete tear. Diagnosis outcomes by MRI and US were analyzed and compared statistically for the accuracy, sensitivity, and specificity in discriminating partial and complete DBT tears.

The accuracy of MRI and US was 86.4% and 45.5% in diagnosis of complete DBT rupture, respectively. Accuracy rate of MRI (66.7%) was the same as US in diagnosis of partial tear. Overall accuracy rate of MRI (80.6%) was higher than US (51.6%) in diagnosis all DBT avulsion with an odds ratio of 3.9. Sensitivity and specificity of MRI were 76.0% and 50.0%, while that of ultrasonography were 62.5% and 20.0%.

The findings of this study suggest that MRI is a more accurate imaging modality at correctly identifying the type of DBT tear although US is more cost-effective.

III, Cohort study, Diagnosis study.