Objective:To investigate the biomechanical characteristics and clinical outcomes of arthroscopic superior capsular reconstruction for massive irreparable rotator cuff tears (MIRCT) using the long head of biceps tendon (LHBT) with tenotomizing its distally or not (the "Chinese way" ).Methods:Eight fresh-frozen cadaveric shoulders were used to create a MIRCT model by detaching the footprints of the supraspinatus and infraspinatus tendons on the greater tuberosity. LHBT autograft was transferred and securely fixed onto the footprint of supraspinatus tendon for superior capsular reconstruction. Further, all cadaveric specimens were assigned to the tenotomy group or reservation group (4 cadaveric specimens in each group) according to whether the distal part of LHBT was tentomized or not. Biomechanical tests were conducted to observe the stiffness, ultimate load of fixed LHBT and to measure the length between LHBT tear site and its insertion on the superior labrum. A total of 41 patients with MIRCT who underwent arthroscopic superior capsular reconstruction using LHBT autograft between July 2016 and December 2018 were enrolled in the study. There were 17 males and 24 females, aged from 46 to 76 years (62.6±7.3 years). All patients were assigned to the tenotomy group (23 cases) or reservation group (18 cases) according to whether the distal part of LHBT was tentomized or not. The visual analogue scale (VAS), University of California, Los Angeles (UCLA) score, American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score and Fudan University Shoulder Score (FUSS) were used to evaluate the clinical outcomes. The range of motion (ROM) of shoulder was recorded before and after operation. Magnetic resonance imaging was used to assess the structural integrity of reconstructed tissue at 12 months after operation (refers to the failure of the transposed LHBT, which may be accompanied by a retear of partial repaired supraspinatus tendon).Results:Biomechanical research showed that the stiffness, ultimate load of fixed LHBT and the length between LHBT tear site and its insertion on the superior labrum in the reservation group (54.0±6.6 N/mm, 141.8±15.9 N, 93.3±12.4 mm, respectively) were significantly higher than those in the tenotomy group (25.7±4.2 N/mm, 80.8±8.0 N, 47.4±2.0 mm, respectively) ( P<0.05). All patients were followed up for 12-18 months (14.5±1.8 months) without significant complications and adverse reactions. No matter the distal part of LHBT was tentomized or not, the ROM and clinical scores (VAS score, UCLA score, Constant-Murley score, ASES score and FUSS) of patients improved significantly at 1 year follow-up than that before operation ( P<0.05). However, there were no significant differences between the reservation group and tenotomy group in terms of postoperative ROM [flexion, abduction, external rotation at side, internal rotation (vertebral level) were 144.3°±15.5° vs. 148.0°±10.3°, 145.1°±14.1° vs. 142.3°±11.2°, 67.3°±14.4° vs. 62.7°±11.7°, 8.3±2.1 vs. 7.8±2.5, respectively], VAS scores (2.3±1.6 vs.1.5±1.2), functional scores (Constant-Murley score, UCLA score, ASES score and FUSS were 88.2±11.4 vs. 85.6±9.6, 29.3±2.8 vs. 31.4±3.5, 86.8±11.8 vs. 82.6±9.2, 92.1±10.1 vs. 88.3±8.2, respectively) and structural failures (35.2% vs. 30.0%, P>0.05). Conclusion:Arthroscopic superior capsular reconstruction using LHBT with reserving its distal part could achieve higher mechanics strength. However, the short-term follow-up showed that tenotomizing the distal part of LHBT exerted no obvious influence on postoperative function and structural integrity.