Presentation
A few days prior to the presentation, the patient had an acute onset, the non-traumatic origin of severe pain involving the left shoulder.
Patient Data
There is soft calcification without posterior acoustic shadow involving subscapularis tendon; measuring about 35 x 8 x 4 mm. Calcification is along bursal side fibers. However, on lateral aspect calcification appears to enter into lesser tuberosity through a cortical defect. There is another soft small calcification (about 4 x 3 mm) in infraspinatus tendon.
Biceps long head, supraspinatus, teres minor tendons and rest of the subscapularis-infraspinatus tendons show normal echopattern. There is no tendon tear.
There is no bursal effusion. Supraspinatus and infraspinatus muscle bellies show normal volume without fatty infiltration.
Case Discussion
An adult female had an acute onset of left shoulder pain about one week prior to the ultrasound. Ultrasound shows a large calcification in subscapularis tendon which appears to extend into the lesser tuberosity of the humeral head. There is also smaller calcification in the infraspinatus tendon.
Rotator cuff calcific tendinosis involves more commonly supraspinatus tendon. Calcification can be 'hard' showing a posterior acoustic shadow on ultrasound. Calcification can be 'soft' without posterior acoustic shadow as in this case. Calcium can migrate to subbursal space and into bursa causing bursitis. Calcium migration into the humerus head is less common. Supraspinatus/infraspinatus calcification can migrate in greater tuberosity of the humeral head and subscapularis calcification can migrate in the lesser tuberosity as it appears in this case. MRI is required to look for edema in the bone in such a case.