Review Question - QID 219739

Calcific tendonitis involves fibrocartilaginous metaplasia of the tendon in the early precalcific stage (Answer 1).

The patient presents with atraumatic shoulder pain, limited range of motion, and a catching sensation with activity. All of these are symptoms potentially attributed to calcific tendonitis near the rotator cuff insertion. The pathophysiology of calcific tendonitis is divided into three stages. First is the precalcific stage when the tendon undergoes fibrocartilaginous metaplasia. Second is the calcific stage, which is subdivided into three phases: formative (characterized by cell-mediated calcific deposits), resting (lacks inflammation), and resorptive (phagocytic resorption and vascular infiltration), the latter of which is the most painful clinically. Finally, the postcalcific stage involves the resorption of calcium and tissue remodeling. Plain radiographs are the mainstay of diagnosis, and the first line of treatment is physical therapy with stretching and strengthening exercises, NSAIDs, and corticosteroid injections.

Suzuki et al. reviewed the pathogenesis and management of rotator cuff calcific tendonitis and described the established work of Uhthoff and Loehr who first proposed the process of cartilaginous metaplasia within the precalcific stage. They discussed the utility of plain radiographs within the diagnostic workup and nonsurgical management including NSAIDs, corticosteroid injections, and physical therapy. The authors concluded that further elucidation of the disease pathogenesis is warranted to better guide optimal treatment strategies.

The pathogenesis of calcific tendinopathy had previously been thought of as a primarily degenerative process prior to the work of Uhthoff and Loehr, who proposed three distinct stages of disease evolution: the precalcific, calcific, and postcalcific stages. They described fibrocartilaginous metaplasia within the precalcific stage in which tenocytes become chondrocytes. This process is followed by calcification and subsequent resorption in the later stages. The authors concluded by emphasizing the importance of the proper determination of disease stage to guide treatment decisions, with surgical intervention warranted in refractory cases within the formative phase of calcification.

Figure Descriptions:
Figure A is an AP radiograph demonstrating calcification along the course of the supraspinatus tendon consistent with calcific tendonitis.
Figure B is an AP radiograph demonstrating superior migration of the humeral head within the glenoid and advanced degenerative changes consistent with chronic rotator cuff tear arthropathy.
Figure C is an axial MRI image demonstrating high T2 fluid signal intensity surrounding a thickened biceps tendon indicative of tenosynovitis.
Figure D is a coronal MRI image demonstrating superior migration of the humeral head within the glenoid and retracted supraspinatus and infraspinatus tendons consistent with a chronic rotator cuff tear.
Figure E is an AP radiograph demonstrating humeral head osteolysis, acromioclavicular joint widening, bony sclerosis, and soft tissue swelling consistent with neuropathic osteoarthropathy of the shoulder.

Incorrect Responses:
Answers 2-5: These disease processes do not involve fibrocartilaginous metaplasia as part of the underlying pathogenesis.