BackgroundArthroscopic surgery has been established as an efficacious intervention for the treatment of rotator cuff tears. The primary aim of this study was to analyze the modifications in the lateral acromial angle (LAA) subsequent to rotator cuff repair surgery using single‐row rivet fixation and double‐row rivet fixation techniques. Furthermore, we sought to investigate the influence of LAA on the prognosis of rotator cuff repair surgery.MethodThis observational study retrospectively enrolled 105 patients diagnosed with degenerative rotator cuff tears who underwent arthroscopic rotator cuff repair between 2016 and 2019. Following the exclusion of two patients with subscapularis or superior labrum anterior and posterior (SLAP) tears, as well as three patients who were lost to follow‐up, a cohort of 100 patients was included for clinical and imaging evaluation. Among these individuals, 50 were assigned to the double‐row repair group, whereas the remaining 50 comprised the single‐row repair group. Bilateral shoulder magnetic resonance imaging (MRI) scans were conducted no less than 24 months post‐surgery. Experienced arthroscopic surgeons, blinded to the LAA measurements, assessed the rotator interval (RI) using a control MRI. Functional assessment was performed using the University of California, Los Angeles (UCLA) quick disability of the shoulder and arm, shoulder and hand (qDASH) score. The Wilcoxon signed‐rank test for dependent samples was employed to compare data between the pre‐ and post‐intervention groups. Pearson correlation coefficients were calculated to evaluate the relationship between different parameters.ResultsThe study population consisted of 73 female patients and 27 male patients, with a mean age of 58.32 ± 5.29 years and a mean follow‐up duration of 25.88 ± 8.11 months. Preoperatively, the mean LAA was 75.81° ± 11.28°, RI was 4.78 ± 0.62, UCLA score was 17.54 ± 2.44, and qDASH score was 2.45 ± 0.25. The average tear size was 8.95 ± 2.11 mm. A statistically significant difference in LAA was observed between the preoperative and postoperative measurements, with the double‐row repair group exhibiting a greater LAA than the single‐row repair group. Finally, a significant correlation was identified between LAA, RI, and qDASH scores after a 24‐month follow‐up period.ConclusionAccording to our findings, the utilization of double‐row rivet fixation has a greater LAA angle than single‐row rivet fixation. Moreover, this preservation of LAA is significantly associated with the functional recovery of the shoulder joint.