Shoulder capsule shrinkage and consequences on shoulder movements.

A study was designed to find landmarks to avoid restriction of range of motion or insufficient shortening of the ligaments after thermal shoulder capsule shrinkage. In 15 nonembalmed shoulders from cadavers, shrinkage was done in three steps: (1). the middle glenohumeral ligament, (2). the anterior part of the inferior glenohumeral ligament, and (3). the posterior part of the glenohumeral ligament. Before and after each step passive range of motion of the glenohumeral joint was studied. Results indicated that flexion and the external rotation were not affected. External rotation in the scapular plane with 45 degree elevation diminished after shrinkage of the middle glenohumeral ligament. External rotation in full abduction diminished after shrinkage of the anterior part of the inferior glenohumeral ligament. Abduction diminished after shrinkage of the anterior and posterior parts of the inferior glenohumeral ligament. Internal rotation in full abduction was restricted after shrinkage of the posterior part of the inferior glenohumeral ligament. These results show a constant relation between the reduction of a given movement and the shrunken area, by providing useful landmarks to reduce the passive hyperabduction that is constant in anterior shoulder instability and to control the immediate effects on the other ranges of motion. To control the immediate consequences of shrinkage may help avoid excessive restriction of motion or insufficient reduction of capsular redundancy.