We reported the results of infraspinatus muscle transfer for massive rotator cuff tear. 17 patients received infraspinatus muscle transfer. There were 13 males and 4 females with an average age of 70 years (55 to 81 years). The patients were affected on the right side (dominant side) except one case. The etiology of the rotator cuff tears was fell down in 6, farm work in 4, sports in 2 and unknown in 5. All patients had rest and motion pain, contracture of the shoulder was not observed and active ROM (a-ROM) was under 60 degrees in 5 cases. The follow up period averaged 17 months (range, 9 to 24 months). A brace with 30 degrees abduction was applied to all patients after surgery, they started passive ROM exercise from the day after surgery. A-ROM exercise without a brace was started from 6 to 8 weeks after surgery. The structural outcome was evaluated with preoperative and postoperative MRI. All patients showed infraspinatus muscle atrophy in preoperative MRI. Shoulder pain disappeared in 8 patients, and improved in 9 cases. The average a-ROM of flexion/abduction/external rotation improved from 94/92/47 to 156/166/44, supraspinatus tests were negative after surgery. The average JOA score significantly improved from 56 to 91. All patients showed no infraspinatus tendon tear after surgery in postoperative MRI. Infraspinatus muscle transfer was an effective method for irreparable massive rotator cuff tear in spite of the presence of infraspinatus muscle atrophy.
