Triple-row technique reduces gap formation and elongation compared with the suture-bridge technique.

Abstract

The suture-bridge (SB) technique is widely used for rotator cuff repair. However, re-tear rates remain high, suggesting that further optimization of repair constructs is necessary. The triple-row (TR) technique, which incorporates an additional middle row of fixation, has been proposed to enhance tendon stabilization, but its mechanical performance remains unclear. This study aimed to compare the mechanical properties of SB and TR repair techniques for rotator cuff tears. Based on the middle-row stitch technique, TR repair was classified as double-simple (TR-DS), double-horizontal mattress (TR-DM), and Mason-Allen (TR-MA). Biomechanical testing was performed using 11 rotator cuff repair models comprising a three-dimensional humeral bone model and silicone rubber tendon for each repair technique. After preloading, the four repair constructs (SB, TR-DS, TR-DM, and TR-MA) were loaded cyclically for 200 cycles from 10 to 100 N, followed by increasing the load to failure at 1 mm/s. Gap formation, cyclic elongation, and the ultimate failure load were compared using one-way analysis of variance with Tukey-Kramer post hoc tests. Compared with SB repair, all TR repairs exhibited significantly less gap formation (all p < 0.001) and cyclic elongation (all p ≦ 0.006). The ultimate failure load did not differ significantly between SB and TR repairs. While TR-MA exhibited superior mechanical properties across all outcomes, no significant difference was found among the TR constructs. Compared with SB repair, TR repair significantly reduced gap formation and elongation. These findings may support consideration of TR repair when enhanced initial repair stability is desired.