Functional outcomes and MCID achievement at 3 and 6 months after knotless double-row rotator cuff repair: an ambispective (retrospective–prospective) cohort study

Background Minimal clinically important difference (MCID) provides a patient-centered measure of meaningful recovery after rotator cuff repair, but data on early MCID achievement following knotless double-row repair remain limited. This study evaluated functional outcomes and MCID achievement at 3 and 6 months and explored associations with selected tear-related structural factors. Materials and methods An ambispective (retrospective–prospective) cohort study was conducted in 39 patients undergoing arthroscopic knotless double-row rotator cuff repair. Pain and functional outcomes were evaluated preoperatively and at 3 and 6 months postoperatively using the Visual Analog Scale (VAS), Constant–Murley Score (CMS), and University of California, Los Angeles (UCLA) Shoulder Score. MCID thresholds were defined as ≥ 10.4 points for CMS and ≥ 3.5 points for UCLA. MCID achievement rates were calculated, and exploratory analyses were performed to assess associations between tear size, tendon retraction, fatty degeneration, and clinically meaningful improvement. Results Mean VAS improved from 6.82 ± 1.12 preoperatively to 2.95 ± 0.76 at 6 months ( p < 0.001). Mean CMS improved from 42.64 ± 3.77 to 81.26 ± 5.84, and mean UCLA score improved from 14.05 ± 4.83 to 30.23 ± 2.41 at 6 months (both p < 0.001). At 3 months, MCID was achieved in 87.2% of patients for CMS and 74.4% for UCLA. By 6 months, all patients in this cohort achieved MCID for both outcome measures. Exploratory subgroup analyses showed no statistically significant associations between tear size, tendon retraction, fatty degeneration, and 3-month MCID achievement. Conclusion Arthroscopic knotless double-row rotator cuff repair provided substantial early pain relief and functional improvement, with high rates of clinically meaningful recovery by 3 months and all patients in this cohort exceeding MCID thresholds by 6 months. Exploratory subgroup analyses did not identify statistically significant associations between tear-related structural factors and MCID achievement; however, these findings should be interpreted cautiously given the limited sample size. Clinical trial number Not applicable.