Vascularity and tendon pathology in the rotator cuff: A review of literature and implications for rehabilitation and surgery

Objective: To compile histological and imaging research detailing the microvascularity of the rotator cuff and determine the clinical application of these findings for clinicians. Methods: A computer-assisted literature search of MEDLINE (1966 to September 2008) using keywords related to blood flow to the shoulder and limited to humans and English language. A hand search was also performed by three of the authors. Results: Nineteen studies met inclusion and exclusion criteria. Conclusions: The relationship between the variables of vascularity, age and degeneration remains unclear. Recent studies with stronger design and better technology support the fact that increased vascularity is a normal response to smaller tears, but that as tear size increases the healing response fails and decreased vascularity is observed. Also, impingement may cause hypovascularity. These studies support the possibility that people without symptoms may have normal blood flow even with ageing. Finally, exercise may increase blood flow to the rotator cuff. These findings have both surgical and rehabilitation implications.