Background <p>Massive rotator cuff tears (MRCTs) represent a complex surgical challenge with high retear rates. While biomechanical studies favor double-row techniques, clinical comparisons of Modified Double-Row Suture Bridge (MDR-SB) versus Traditional Single-Row (SR) repairs remain limited, particularly regarding functional recovery patterns and complication profiles. Therefore, this study aimed to compare the 12-month structural integrity, functional recovery trajectories, and complication profiles between the MDR-SB and SR techniques in patients with MRCTs and preserved muscle quality.</p> Methods <p>This retrospective cohort study analyzed 190 consecutive patients with MRCTs undergoing arthroscopic repair (2020–2023). Participants were stratified into MDR-SB (<i>n</i> = 95) and SR (<i>n</i> = 95) groups. Both groups followed an identical, standardized postoperative rehabilitation protocol from the outset, which was modified only if postoperative stiffness was diagnosed. The primary outcome was the 12-month retear rate assessed via Sugaya classification on magnetic resonance imaging (MRI). Secondary outcomes included functional scores (University of California, Los Angeles Shoulder Score [UCLA], Constant-Murley Score [Constant], American Shoulder and Elbow Surgeons Score [ASES]), range of motion, strength recovery, and complications. Propensity score matching (yielding 68 matched pairs) addressed baseline imbalances in age, tear size, and fatty infiltration.</p> Results <p>After propensity score matching, the MDR-SB group demonstrated a significantly lower 12-month retear rate compared to the SR group (14.7% vs. 29.4%, <i>P</i> = 0.019); multivariable analysis confirmed this advantage (Adjusted OR 0.42, <i>P</i> = 0.012). Subgroup analyses indicated that the reduction in retear risk with MDR-SB was most pronounced in patients with larger tears (&gt; 5&#xa0;cm) and those with minimal fatty infiltration (Goutallier stage &lt; 2). Analysis of secondary outcomes revealed that the MDR-SB group was associated with an accelerated early functional recovery and superior final strength restoration. Specifically, significantly higher Constant, ASES, and UCLA scores were observed at the 3- and 6-month postoperative intervals (all <i>P</i> &lt; 0.001), and the affected/unaffected abduction strength ratio was significantly greater in the MDR-SB group at the 12-month final follow-up (86.0% vs. 76.8%, <i>P</i> &lt; 0.001). Transient postoperative stiffness occurred more frequently with MDR-SB (16.2% vs. 5.9%, <i>P</i> = 0.049), though all cases resolved by 6 months following a modified, intensified physical therapy regimen.</p> Conclusion <p>For patients with MRCTs and preserved muscle quality (Goutallier stage &lt; 2), the MDR-SB technique demonstrates superior 12-month structural integrity, more favorable functional recovery trajectories throughout the postoperative period, and a distinct complication profile characterized by superior strength restoration and manageable transient stiffness compared to SR repair.</p>