Atypical Location of Calcific Tendinitis in the Shoulder.
American Journal of Physical Medicine and Rehabilitation
Case Diagnosis: Right Infraspinatus Calcific Tendinitis
Case Description: A 47 year-old female presented with acute on chronic right shoulder pain. Her pain was aching in nature and without a history of trauma. Examination showed tenderness over the lateral and posterior proximal humerus with a decrease in active range of motion with abduction and external rotation secondary to pain. Rotator cuff muscle strength was normal and no pain was elicited with shoulder impingement tests. A diagnostic ultrasound (US) showed a large calcium deposit measuring 3 cm x 3 cm with a hypoechoic center. Ultrasound Guided Needle Lavage (UGNL) was performed for thirteen minutes. At her twelve-week appointment, the patient had resolution of her shoulder pain.
Discussions: Rotator cuff calcific tendinitis (RCCT) is a common cause of shoulder pain with a predominance in women from ages 30 to 60 years old and with an association with endocrine disorders. Calcium hydroxyapatite crystals are deposited in or around a tendon that occur most commonly in the supraspinatus and only about 15% of the time in the infraspinatus. The pathogenesis has three distinct stages: precalcific (fibrocartilaginous metaplasia), calcific (further subdivided into a formative, resting and resorptive phases) and postcalcific. Pain is typically experienced during the resorptive phase due to growth of the calcium deposits and through inflammation induction. Diagnosis is through Xray, US, Computed Tomography or Magnetic Resonance Imaging. Under US, calcific deposits appear as hyperechoic structures with posterior acoustic shadowing or can be amorphous or globular. Further classification systems based on calcifications types and appearances correspond to their respective stages.
Conclusions: This case highlights the presentation of calcific tendinitis in an atypical location that was not amenable to conservative treatment. UGNL is an effective alternative to treat large calcific deposits from RCCT. Calcific tendinitis should be a differential diagnosis for non-traumatic shoulder pain in middle aged persons.
Mazar A, Mendez J. Atypical location of calcific tendinitis in the shoulder. Am J Phys Med Rehab. 2021;100(4 suppl.):a33-a34.