Matrix Metalloproteinase and Tissue Inhibitor of Matrix Metalloproteinase Levelsare Specifically Altered in the Torn Rotator Cuff

Introduction: Rotator cuff (RC) disease is the most common cause of shoulder pain in adults (1). The incidence of full-thickness RC tears has been reported to be as high as 40% (2). Several studies have documented the pathological changes associated with RC disease including disruption and thinning of fascicles, foci of granulation tissue, and dystrophic calcification (3). However, despite a large volume of knowledge on the incidence and management of RC disease, the etiology or pathogenesis of the disease remains controversial. This has hindered biological treatment options for RC disease.