Article

The purpose of this study was to evaluate the effects of glenohumeral rotations and humeral head translations on supraspinatus tendon morphology. Design. A convenience sample of cadaver shoulders was used to measure supraspinatus tendon shape and dimensions from MRI images. Background. Epidemiological evidence has indicated that shoulder elevation and external rotation may be risk factors for rotator cuff tendon pathology. But little is known about how these postures affect tendon morphology. Methods. Measurements of supraspinatus tendon morphology were made from three-dimensional reconstructions based on T2-weighted fast spin-echo magnetic resonance images. Seven cadaver arms were imaged at neutral, 45degrees external and 45degrees internal rotations at 0degrees, 30degrees, and 60degrees of glenohumeral abduction. Measurements of the anterior, middle, and posterior portions of the tendon were made using ANALYZE(TM) software. Results. The supraspinatus tendon was twisted at the muscle-tendon junction of the middle and posterior portions in 45degrees external and 45degrees internal axial rotations of the humerus, especially over 30degrees of abduction. Abduction over 30degrees shortened the entire supraspinatus tendon. External and internal rotation motions elongated the anterior and posterior portions, respectively. Conclusions. Arm posture affects morphology of the supraspinatus tendon. Relevance The results support the epidemiologic evidence linking external rotation and abduction to supraspinatus tendon disorders. (C) 2004 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS