Aberrant origin of the long head of the biceps: a case series

MRI of Selected Abnormalities at the Anterior Superior Aspect of the Shoulder: Potential Pitfalls and Subtle Diagnoses

“…Variations of the LHB tendon that have been described previously range from complete absence of the intraarticular portion of the tendon, which is very rare, to a spectrum of variant origin sites of the intraarticular segment of the tendon, including the presence of two separate origins [4,[6][7][8][9][10][11][12]. Although arthroscopy studies describe a number of variants within a "mesotenon" category, essentially consisting of a thin mobile synovial connection between the joint capsule along the undersurface of the rotator cuff and the intraarticular LHB tendon with a normal tendon origin from the supraglenoid tubercle or superior labrum [11], most of these prior reports do not include MRI correlation, and, presumably, these types of variations would be difficult to detect with imaging.…”

“…and separate origins that merge together before exiting the joint as a single tendon, also referred to as a "bifurcate" or "Y-shaped origin" of the LHB tendon [4,[7][8][9][10][11][12]. In this setting, one of the two origins is typically from the superior joint capsule or rotator cable, and the second may be from the normal superior glenoid site or may be from the scapula medial to the supraglenoid tubercle [10,12]. In some of the cases reported in the literature, the extraarticular segment of the LHB tendon is noted to be hypoplastic in the setting of variant intraarticular LHB tendon anatomy [4,7].…”

Sonography of the Accessory Head of the Biceps Brachii

“…A recent cadaveric study with MRI correlation showed the accessory head of biceps brachii muscle at the anterolateral aspect of the biceps brachii long‐head tendon, at the level of the bicipital groove 1 . Arthroscopic reports have confirmed an accessory tendon at this site, consistent with a normal variant 12 – 14 . In the study by Gheno et al, 1 the average short‐ and long‐axis dimensions of the accessory biceps were 0.85 and 6.2 mm at the level of the bicipital groove.…”

“…Dierickx et al 13 , 15 speculated that the accessory biceps may cause impingement in a young patient, which could evolve into a rotator cuff tear. Others described the accessory tendon as a benign anatomic variant that does not contribute to shoulder disorders 12 . More study is needed to determine whether this normal variant is ever symptomatic or pathologic or whether it can predispose to biceps tenosynovitis or other disorders.…”

“…Sonography has been shown to be an excellent imaging modality to evaluate muscles and tendons, with advantages and disadvantages compared to magnetic resonance imaging (MRI) 10 , 11 . Recently the MRI and arthroscopic appearance of the accessory head of the biceps brachii has been described 1 , 9 , 12 – 14 . The purpose of this series is to demonstrate the sonographic appearance of the accessory head of the biceps brachii in the bicipital groove.…”