Objective To compare the early effectiveness of arthroscopic repair of moderate rotator cuff tears with single-row modified Mason-Allen technique and double-row suture bridge technique. MethodsThe clinical data of 40 patients with moderate rotator cuff tears who met the selection criteria between January 2021 and May 2022 were retrospectively analyzed. Among them, 20 cases were repaired with single-row modified Mason-Allen suture technique (single-row group) and 20 cases with double-row suture bridge technique (double-row group). There was no significant difference in gender, age, disease duration, rotator cuff tear size, and preoperative visual analogue scale (VAS) score, Constant-Murley score, and T2* value between the two groups (P>0.05). The VAS score, Constant-Murley score (including subjective influence, pain, flexion, internal rotation, external rotation, abduction, and muscle strength score) were compared between the two groups before operation and at 6 weeks, 3, 6, and 12 months after operation. Functional MRI and ultrashort-echo-time (UTE)-T2* technique were performed to calculate T2* value and quantitatively evaluate the healing of rotator cuff tissue; and the healing of rotator cuff was evaluated by Sugaya classification at 12 months after operation. ResultsPatients in both groups were followed up 1 year. There was no complication such as muscle atrophy, joint stiffness, or postoperative rotator cuff tear. The intra-group comparison showed that the scores of pain, subjective influence, flexion, abduction, and muscle strength in Constant-Murley scores at each time point after operation in the two groups were significantly higher than those before operation, while VAS scores were significantly lower than those before operation (P<0.05). Internal rotation, external rotation, and total score of Constant-Murley score in the two groups were lower at 6 weeks due to abduction immobilization within 6 weeks after operation, and gradually increased at 6 months after operation, with significant differences at 3, 6, and 12 months after operation when compared with those before operation and at 6 weeks after operation (P<0.05). The T2* values of the two groups showed a downward trend over time, and there were significant differences between the two groups at other time points (P<0.05), except that there was no significant difference between at 6 and 12 months after operation in the single-row group and between at 3, 6, and 12 months after operation in the double-row group (P>0.05). The comparison between groups showed that the VAS score and T2* values of the double-row group were significantly lower than those of the single-row group at 6 weeks, 3 months, 6 months, and 12 months after operation (P<0.05). The scores of subjective influence, flexion, abduction, and internal rotation in the double-row group were significantly better than those in the single-row group at 6 weeks and 3 months after operation (P<0.05), and the external rotation score and total score in the double-row group were significantly better than those in the single-row group at 3 months after operation (P<0.05), but there was no significant difference at 6 and 12 months after operation (P>0.05). There was no significant difference in muscle strength and pain scores between the two groups at 6 weeks, 3 months, 6 months, and 12 months after operation (P>0.05). There was no significant difference in the results of Sugaya classification between the two groups at 12 months after operation (Z=1.060, P=0.289). Conclusion The effectiveness of arthroscopic repair of moderate rotator cuff tears with modified Mason-Allen technique and double-row suture bridge technique is satisfactory, but suture bridge technique is helpful to the early rehabilitation training of shoulder joint and the recovery of motor function of patients.