Many authors reported post operative good results of arthroscopic rotator cuff repair (ARCR) for small or medium size tears. However, high re-tear rate and poor functional outcomes of ARCR for massive tears were reported and those indications were obscure. The aim of this study was to determine the accurate operative indications of ARCR for massive tears according to the correlation between the preoperatively remained shoulder function and the postoperative outcome. We retrospectively evaluated 26 patients (18 males and 8 females), who had undergone ARCR for massive tears with a minimum 6 months follow-up. The average age at the surgery was 67.7 years old. Preoperative patients' factors: age, sex, longitudinal tear size, transverse tear size, involved torn tendon, ROM of active flexion, ROM of active abduction and evaluation by the Japanese Orthopaedic Association (JOA) shoulder scoring system were statistically analyzed about correlation with the postoperative evaluation by JOA scoring system at 6 months follow-up. Preoperative factors such as age, sex, longitudinal tear size, ROM of active abduction and preoperative evaluation by JOA scoring system did not significantly affect the postoperative evaluation by JOA scoring system. However, preoperative factors such as transverse tear size (over 40mm), involved torn tendon (torn subscapularis tendon), ROM of active flexion (below 90 degrees) did significantly affect the postoperative evaluation by JOA scoring system. Relative good surgical indications of ARCR for massive tears were as follows: below 40mm in transverse tear size, subscapularis tendon was not torn and a possible over 90 degrees of active flexion.
