Ultrasound demonstration of distal biceps tendon bifurcation: normal and abnormal findings.

We demonstrate the US appearance of the distal biceps tendon bifurcation in normal cadavers and volunteers and in those affected by various disease processes. Three cadaveric specimens, 30 normal volunteers, and 75 patients were evaluated by means of US. Correlative MR imaging was obtained in normal volunteers and patients. In all cases US demonstrated the distal biceps tendon shaped by two separate tendons belonging to the short and long head of the biceps brachii muscle. Four patients had a complete rupture of the distal insertion of the biceps with retraction of the muscle belly. Four patients had partial tear of the distal biceps tendon with different US appearance. In two patients the partial tear involved the short head of the biceps brachii tendon, while in the other two patients, the long head was involved. Correlative MR imaging is also presented both in normal volunteers and patients. US changed the therapeutic management in the patients with partial tears involving the LH of the biceps. This is the first report in which ultrasound considers the distal biceps tendon bifurcation in detail. Isolated tears of one of these components can be identified by US. Knowledge of the distal biceps tendon bifurcation ultrasonographic anatomy and pathology has important diagnostic and therapeutic implications.