Congenital bilateral absence of the long head of biceps tendon
Presentation
Fall on the ground about 10 days before the presentation. Complaining of left shoulder pain. No previous history of trauma or surgery of either shoulder.
Patient Data
The symptomatic left shoulder shows absent biceps tendon in the bicipital groove. There is no medially dislocated biceps long head tendon. Its myotendinous junction is absent at the level of the pectoralis major tendon insertion. The short head of the biceps brachii is normal. The distal biceps tendon is intact. Supraspinatus, infraspinatus, teres minor, and subscapularis tendons are intact. The supraspinatus tendon shows mild heterogeneous echopattern without fluid cleft / volume loss / calcification. Supraspinatus and infraspinatus muscles show normal bulk and echopattern. There is no subacromial-subdeltoid bursal effusion or glenohumeral joint effusion. There is an ill-defined area of increased echogenicity of the subcutaneous fat over the acromial process of the scapula without any fluid cleft/collection. This correlates with the site of pain and represents fat contusion.
The asymptomatic right rotator cuff was examined. The long head of the biceps tendon is absent in the bicipital groove. There is no medially dislocated tendon. There is absent myotendinous junction of the long head of the biceps under the pectoralis major tendon insertion. The short head of the biceps is normal. Subscapularis, supraspinatus, infraspinatus, teres minor tendons are intact and show normal echopattern. Supraspinatus and infraspinatus muscles are normal. There is no bursal or joint effusion.
Case Discussion
A female presented with post-traumatic left shoulder pain for the last few days. Ultrasound shows mild tendinosis of the supraspinatus tendon along with subcutaneous fat contusion over the acromion process of the scapula. The long head of the biceps tendon is absent.
The asymptomatic right cuff also shows the absent long head of the biceps tendon.
With absent biceps long head in the bicipital groove, there are three possibilities with tendon tear and tendon dislocation being most common and congenital absence being very rare.
In the case of the tendon tear, the long head myotendinous junction shows sagging below the level of the pectoralis major tendon.
In the case of the tendon dislocation, the long head myotendinous junction is seen at its normal location under the pectoralis major tendon insertion. A medially dislocated long head biceps tendon is seen overlying / deep to / in the substance of the subscapularis tendon depending on presence or absence of associated subscapularis tendon tear.
The third possibility in case of non-localization of the biceps tendon in the bicipital groove is the congenitally absent tendon as in this case. There is no tendon and so there is no myotendinous junction at the level of the pectoralis major tendon insertion.
Based on the findings, the case shows the bilateral congenital absence of biceps long head tendon. The symptomatic side MRI revealed similar findings (no copyright, not uploaded). The asymptomatic side MRI was not done.