The purpose of this study was to evaluate subscapularis tendon tears and to investigate the prevalence and treatment options according to our new classification. We classified the type and size of tendon tears using arthroscopy. From July, 2002 to October, 2008, we operated on 454 shoulders with rotator cuff tears. We classified subscapularis tendon tears into 4 types. Type 1: partial and longitudinal tear of articular side, pulley is intact, LHB is stable. Type 2: partial tear of superior tendon from lesser tuberosity, LHB is stable or unstable due to dysfunction of pulley. Type 3, 4: complete tear from lesser tuberosity, classified according to the location of “comma sign”, LHB is unstable and a state of partial or complete tear. We could investigate 274 shoulders (males 165, females 109, 155 right shoulders, 119 left shoulders) passed for 1 year at least after operation. Their mean age was 64 years old (33-87). More than 40% of rotator cuff tear patients had complications about subscapularis tendon (Type 1; 10.4%, Type 2; 14.7%, Type 3; 9.6%, Type 4; 9.6%). In Type 4 patients, they got better results than the other types. Subscapularis plays an important role in shoulder functions especially glenohumaral joint stability. We might overlook subscapularis tendon tears when we operate rotator cuff tears. Recently the number of arthrosopic rotator cuff repair is increasing. We can evaluate more in detail of the state of shoulder. Our classification is useful for treatment of subscapularis tendon tears because there is a direct relationship between the types and strategies of treatment. We had every confidence that to evaluate and treat subscapularis tendon tears brings good results after operation.
