Sonographic evaluation of the distal biceps tendon using a medial approach: The pronator window

Objective: The purpose of this report is to describe and demonstrate the potential advantages of a technique to image the distal biceps tendon using a medial approach: the pronator window. Methods: Distal biceps tendon imaging via the medial approach was shown using real-time sonography on an asymptomatic volunteer as well as cadaveric anatomic dissection. Results: The medial approach images the biceps tendon with minimal anisotropy while providing several potential advantages, including (1) complete visualization of the ulnarly facing radial tuberosity and the tapered distal biceps insertion, (2) increased contrast and reduced beam attenuation at the interface between the biceps tendon and overlying brachial artery, and (3) avoidance of the beam-attenuating effects of the supinator encountered when imaging the tendon from a lateral approach. Conclusions: The medial approach to image the distal biceps tendon complements previously described techniques and should be considered in the evaluation of patients presenting with distal biceps tendon disorders. Future clinical studies may elucidate the relative advantages and disadvantages of sonographic distal biceps imaging techniques in specific patient populations.