Effect of Anterior Supraspinatus Tendon Partial-Thickness tears on Infraspinatus Tendon Strain through a Range of Joint Rotation Angles

摘要

BackgroundRotator cuff tears are common shoulder problems whose propagation is difficult to predict because of the structural and mechanical inhomogeneity of the supraspinatus tendon. We have previously shown that the supraspinatus and the infraspinatus tendons mechanically interact when the supraspinatus tendon is intact or exhibits a full-thickness tear so that an increase in supraspinatus tendon strain is paralleled by an increase in infraspinatus tendon strain. Such interaction is critical and suggests that an increase in infraspinatus tendon strain that accompanies an increase in supraspinatus tendon strain may shield the supraspinatus tendon from further injury but increase the risk of injury to the infraspinatus tendon. In this study, the mechanical interactions between the supraspinatus and infraspinatus tendons were evaluated for the commonly occurring supraspinatus tendon partial-thickness tears through a range of rotation angles.