Age / Sex : 87 / F

Chief complaint : Limited of motion, shoulder, right

(History of trauma and dementia)

Courtesy : Ji Young Hwang, Ewha Womans Unversity Mokdong Hospital

Discussion

Answer:  Medial dislocation of biceps tendon long head

Findings: Fat-suppressed PD-weighted axial images show a thick and dark oval structure in anterior aspect of subscapularis tendon. Intraarticular dislocation of the long head of biceps tendon may be easily identified by the empty bicipital groove and the intraarticular course of this rope-like structure from the superior glenoid. In this case, intraarticular medial dislocation of biceps tendon from the bicipital groove is associated with disruption of biceps pulley in massive rotator cuff tear; Full-thickness tear of supraspinatus, infraspinatus, and subscapularis tendon (not shown here).

Diagnosis:

(medial) dislocation of long head of biceps tendon

Differential Diagnosis:

Calcific tendinitis

Buford complex

Loose body

Discussion:

The long head of the biceps tendon (LHBT) arises from the supraglenoid tubercle and the superior glenoid labrum, courses over the top of the humeral head, and goes down into the bicipital groove between the greater and lesser tuberosities. The LHBT sheath communicates with the glenohumeral joint. The LHBT as it courses from the intraarticular to the extraarticular bicipital groove is retained in its proper position by the combined action of the coracohumeral ligament, superior glenohumeral ligament, anterior portion of supraspinatus tendon and cranial portion of subscapularis tendon, which is forming the “biceps pulley”. The disruption of this “biceps pulley” may result in the intraarticular subluxation or dislocation of biceps tendon. Dislocation or subluxation of the biceps tendon may present as an isolated lesion, but it is usually seen in association with rotator cuff disease, especially, involving the anterior portion of supraspinatus tendon or cranial portion of subscapularis tendon. On MR imaging, the dislocated biceps tendon can be identified medial to the empty bicipital groove, most clearly on axial images. Oblique coronal and oblique sagittal images are also useful. The displaced biceps tendon can be identified as either extraarticular or intraarticular, with a variable degree of injury to the surrounding structures. At conventional MR imaging, associated abnormalities of the biceps tendon may manifest as variable degrees of increased signal intensity, changes in the shape of the tendon (thickening, flattening, broadening), and fluid around the displaced biceps tendon. Other abnormalities associated with dislocation of the biceps tendon include an abnormal shape of the bicipital groove, abnormalities of the rotator cuff, disruption of the CHL, disruption and thinning of the subscapularis tendon, and supraspinatus tendon tear

References:

Biceps pulley: normal anatomy and associated lesions at MR arthrography. Radiographics. 2011;31(3):791-810.