While multiple factors have been identified in the pathophysiology of rotator cuff disease, the biochemical and molecular events leading to rotator cuff degeneration and tear have not yet been defined. The subacromial bursa has been implicated in this process. The current study involves the use of histological and immunohistochemical methods to investigate the expression of certain proinflammatory cytokines, proteases and cyclooxygenase enzymes in subacromial bursa. The effect of cortisone injection on these mediators in patients with rotator cuff disease is also unknown. The expression of these chemical mediators may contribute to inflammatory catabolic processes and tissue degradation and may play important role in pathogenesis of rotator cuff disease. We hypothesize that subacromial bursa in patients with rotator cuff disease will produce the pro-inflammatory cytokines that are not expressed or expressed at a low level in patients without subacromial impingement. Also, cortisone injection decreases the expression of catabolic factors in subacromial bursa in patients with rotator cuff disease.
Currently we are developing several studies in this area.