We studied 54 patients operated on for combined supraspinatus and infraspinatus rotator-cuff tears. The presence or absence of the dropping and hornblower’s clinical signs of impaired external rotation were correlated with Goutallier stage-3 or stage-4 fatty degeneration of infraspinatus and teres minor. These grades of fatty degeneration have previously been correlated with a poorer outcome from reconstructive surgery.

We found that hornblower’s sign had 100% sensitivity and 93% specificity for irreparable degeneration of teres minor and the dropping sign 100% sensitivity and 100% specificity for similar degeneration of infraspinatus.

In seven patients, teres minor showed hypertrophy. This muscle can give useful function for the activities of daily living in patients with rotator-cuff tears in whom it is intact.