Congenital Absence of the Long Head of the Biceps Tendon: A Case Report

C ongenital absence of the long head of the biceps tendon is a rare entity. The exact prevalence of this anomaly is unknown; a review of the literature revealed only two reported cases1,2. We present a third case. Several interesting observations and similarities noted among these three cases may have clinical implications regarding shoulder stability. Our patient was informed that data concerning the case would be submitted for publication. Fig. 1 T1-weighted axial magnetic resonance image of the proximal part of the right humeral shaft. Note the hypoplastic bicipital groove and the absence of the long head of the biceps tendon. A thirty-seven-year-old right-hand-dominant man presented to our clinic because of left shoulder weakness. The medical history was notable for spina bifida occulta, congenital inguinal hernia, and an undescended testicle on the right side. The family history was notable for the fact that the father had ankylosing spondylitis and the human leukocyte antigen-B27. Physical examination revealed anterior shoulder instability and mechanical symptoms suggestive of labral pathology. Generalized ligamentous laxity was noted as the patient's thumb could be approximated to the volar aspect of the forearm with wrist flexion. Magnetic resonance imaging of the left shoulder confirmed a labral tear extending from the eleven o'clock position to the six o'clock position. A relatively small long head of the biceps tendon was seen to run along the typical intra-articular course from the bicipital groove to the superior aspect of the labrum (Fig. 1). Although the tendon was believed to be diminished in diameter …