Biceps Tendon Sheath Injection: An Anatomical Conundrum

Long head biceps tendon peritendinous or sheath injections are routinely administered at or immediately distally to the bicipital groove. The main indication for injection remains the clinical diagnosis or treatment of biceps tendinopathy, although true inflammation of the tendon within the bicipital groove is rare. Because the tendon sheath is merely an extension of the joint cavity, it is plausible to assume that an injection into the sheath would result in intraarticular spread. Surprisingly, such an anatomical tenet has a vague confirmation in the published clinical literature. This experiment was undertaken to investigate patterns of injectate spread when peri-tendon injection at the bicipital groove is performed.