Volume and Movement Affecting Flow of Injectate Between the Biceps Tendon Sheath and Glenohumeral Joint: A Cadaveric...

The objective of our study was to determine if flow of injectate between the biceps tendon sheath and the glenohumeral joint is a function of injectate volume or of motion of the upper extremity.

Sixteen upper-extremity fresh-frozen cadaveric specimens were used. Initially, three ultrasound-guided biceps tendon sheath injections were performed using 2, 5, and 10 mL of contrast material. Immediately after the injections, the specimens were imaged using CT. If contrast material was not visualized within the glenohumeral joint, the specimen was manipulated for 5 minutes and reimaged using CT to assess for contrast material within the joint. Five separate ultrasound-guided glenohumeral joint injections were also performed using 5 mL (three specimens), 10 mL (one specimen), and 15 mL (one specimen) of contrast material. The specimens underwent CT, and the presence or absence of contrast material in the biceps tendon sheath was documented before and after manipulation. Next, eight additional ultrasound-guided biceps tendon sheath injections were performed using 2 mL (six specimens) and 5 mL (two specimens) of contrast material.

The 5- and 10-mL biceps tendon sheath injection specimens and the 5-, 10-, and 15-mL glenohumeral joint specimens showed communicating contrast flow on the initial CT study. Only two of the seven 2-mL biceps tendon sheath injection specimens showed flow of contrast material into the glenohumeral joint from the biceps tendon sheath on the initial CT study; the remaining five specimens showed no communication even after manipulation.

Communication between the biceps tendon sheath and the glenohumeral joint may be a function of injectate volume rather than patient movement.