Sonography in the instability of the long head of the biceps tendon confronted with histopathologic and arthroscopic findings.

Disorders of the long head of the biceps tendon (LHBT) are a common source of shoulder pain and disability. This tendon can be well visualized using ultrasonography; however, little is known if such examination allows clinicians to predict pathological changes of the tendon structure. In the study described below, we compare preoperative sonographic findings with the data from shoulder arthroscopy and microscopic examination of the excised tendon fragments in 19 consecutive patients with LHB tendinopathy and clinical suspicion of its instability. Preoperative ultrasonographic (US) inspection assessed several features of the tendon, whereas its stability was verified arthroscopically. In all cases, tenodesis or tenotomy procedures were performed and excised tendon fragments were harvested for microscopic examination based on the semiquantitative Bonar score. The most common US findings were hypoechoic areas, tendon thickening, an increased Power Doppler (PD) signal and mechanical instability. Just as shoulder arthroscopy confirmed all mechanical instability cases detected in US, microscopic assessment revealed advanced degeneration in all samples. Our study indicates that US is a useful tool in identifying cases of advanced instability and LHB tendinopathy, whereas biceps tendon instability is a biomechanically complex, gradually progressing phenomenon, frequently associated with additional shoulder lesions.